October 15, 2019

*EXCLUSIVE* 2011 Heavy-Duty Hurt Locker (Part II)

Part Two

2011 Heavy-Duty Hurt Locker: Brake Test

 Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

40 mph to Zero Brake Test with 19,400 lbs Trailers

During the last HD Shootout, we performed 60-to-zero-mph brake tests to measure stopping distances from 60 mph with the trucks empty and with 2,000 pounds of ballast in their cargo boxes. Instead of repeating that test, this time we measured brake performance with the trailers attached.

Each truck was tested twice, side-by-side with the other trucks, in two tests. Tow/haul mode was on. The exhaust brakes on the Ram and GM trucks were enabled while towing. The Ford’s exhaust brake is automatically enabled when the truck is in tow/haul mode.

Because of the heavy weights involved, we tested stopping power from 40 mph to zero, but we changed things up a bit.

In the first round, the trucks were connected to the trailers via the 7-pin electrical connection, so the trucks’ integrated trailer brake controllers could manage the trailer brakes when we applied our foot to the service brakes inside the truck.


In the second round, we disconnected the electrical connection, so the truck brakes were forced to stop the entire rig — truck and trailer — without any assistance from the trailer brakes.

Why did we do this? The importance of testing trucks without the electrical connection to trailers demonstrates a common problem with 7-pin trailer plug connections. In the RV7-type connection, standard on all pickups today, the male-to-female connection isn’t locked tight. It depends on friction from a brass wedge sliding against a metal blade in 7 places to hold the plug in place. Over time, the plugs flex with truck movement, causing electrical arcing and voids that allow dirt and water in, which can lead to corrosion over time. Whether it breaks, corrodes or pulls away, if you lose connection from truck to the brake or ground wires in the trailer plugs, you lose the trailer brakes. This is why you should check your 7-pin connector often and regularly.

In contrast to our earlier, faster brake test with payload where the GMC Sierra 3500 excelled, this time the Ford F-350 had the best stopping power, followed by the Ram 3500. The Ford needed only 94 feet to stop compared with more than 100 feet for the Ram and Sierra.

Stopping distance grew dramatically when we disconnected the trailer connections, by an average of about 50 percent. The Ford still came to a halt in the shortest distance – 143 feet, about 20 feet sooner than the Ram (164 feet) and Sierra (165 feet).


Why did the Ford perform so much better in this brake test than the GMC and Ram trucks?

Even though Ford has the smallest brake rotors in the class (13.7 inches front and 13.4 inches rear compared with 14 inches for the GMC and 14.1 inches for the Ram), it appears to manage ABS more effectively with or without trailer attached. The lack of any “disconnected trailer brake” signal to the truck didn’t seem to change what the yaw signal was to the Ford.

The GMC Sierra with trailer brakes connected seemed to give confusing signals to the ABS computer, not allowing full brakes as the truck slowed down, allowing it to roll forward to pass the stopped Dodge at slow speed.

Ford and GM use truck brake hydraulic pressure from the master cylinder to activate the integrated trailer brake controller, whereas the Ram’s trailer brake controller relies on an integrated accelerometer. This means Ford and GM don’t require trailer movement to activate the brakes, while Ram measures the movement of the trailer to help manage brake application. All three brands’ integrated trailer brake controllers use accelerometer-based motion readings when the ABS computer takes over during hard braking.

2011 Heavy-Duty Hurt Locker: Davis Dam Grade Climb

Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Davis Dam Grade Climb

After nearly four years of deliberation and negotiation, truck manufacturers and the Society of Automotive Engineers are expected to agree to the industry’s first tow testing standards for pickups by late this year.

The standard, known as J2807, establishes tow-vehicle performance requirements against the following criteria to establish maximum ratings: timed acceleration on level ground and up a 12 percent incline; maintaining speed on a real-world grade; understeer; trailer-sway response; braking and park brake at gross combined weight; and tow-vehicle hitch/attachment structure. To minimize test variations, J2807 provides standard test trailer specifications and requirements for use in these tests.

Once J2807 is implemented, truck buyers will finally have an apples-to-apples comparison for the trailer-towing capacity of all light-duty pickups. All manufacturers are expected to follow it starting with the 2013 model year. PickupTrucks.com is using parts of the standard for testing, including the standardized hill climb at Davis Dam Grade.

Topographical map of Davis Dam Grade based on GPS data collected by our VBOX and exported to Google Earth. The red line representing our timed course starts at the upper right (near the Colorado River) and finishes 59,000 feet (11.17 miles) later in the lower left at Union Pass.

The Davis Dam grade test site is on U.S. Highway 68, just outside Bullhead City, Ariz. We started our run at the intersection of Highway 68 and McCormick Boulevard, the same place that J2807 specifies. The top of the grade is about 12 miles from the starting point. We measured 11.17 miles (59,000 feet) from start to finish, just past the Union Pass marker at the summit. The incline is a steady 5 percent for nearly its entire length.

Each truck had two clean runs up the grade at wide open throttle from start to finish. Runs during which the driver let off the accelerator, braked or both were not counted. The trucks were in tow/haul mode, with the exhaust brakes on and the air conditioning set to maximum for the entire climb.

The first run was completed late in the afternoon. The second run was completed the next morning. We averaged the two runs to calculate the fastest time.

Despite the grade’s length and the hot temperatures, which we thought would expose and exaggerate any weaknesses in cooling or power, all of the trucks were very competitive.

The Ford F-350 and GMC Sierra sparred fiercely with each other for the fastest time. The Ford was fastest on the first run and the GMC was fastest on the second. GMC’s average time up the hill was 11.5 seconds faster than the Ford’s time. The Ram 3500 finished just more than a minute behind the F-350.

This chart shows each truck's speed climbing Davis Dam Grade against the clock at wide open throttle. The GMC Sierra 3500's fastest run was 671.3 seconds, the Ford F-350's best time was 710.8 seconds and the Ram's quickest climb was 774.2 seconds. The sloped lines represent each truck's position climbing the mountain.

This chart shows the speeds of the three trucks relative to each other over the 59,000 foot (11.17 mile) run to the top of Davis Dam Grade. Note how similar the speed patterns are for each truck as the grade changes throughout the climb.

The GMC Sierra 3500’s quickest time up Davis Dam was 11 minutes, 11.3 seconds, and its average speed pulling from 500 feet up to 3,000 feet in elevation was 58.35 mph. Top speed was 69 mph for a few moments where the highway’s slope decreased to 3 percent for several hundred yards.

The Ford F-350’s best time up the grade was 11 minutes, 50.8 seconds at an average speed of 54.9 mph. Its top speed was 63.15 mph.

The Ram’s fastest run was 12 minutes, 54.2 seconds at an average speed of 50.64 mph. Its top speed was 62 mph, at the same spot the GMC and Ford hit their top speeds.

Of the three trucks, the Sierra ran coolest up the hill, even when the outside temp was more than 100 degrees. Coolant temp climbed by just 3 degrees, from 187 to 190, and transmission temp ranged from 210 to 215.

While the Ford was almost as fast as the GMC, its powertrain ran hotter. Coolant peaked at 231 degrees, and the transmission temp hit as high as 216. The Ram stayed cooler than the Ford but warmer than the GMC. Coolant temp topped out at 226 degrees, and the transmission hit 213.


All the trucks’ engine fans turned on during their runs to cool things down, but the Ram’s fan was the loudest. The Ram also had the roughest shifts and seemed to have difficulty figuring out whether to stay in 3rd or 4th gear, hunting for a sweet spot among the two gears.

It’s worth noting that all three trucks would have easily passed the SAE J2807 minimal speed standard, which is 35 mph on Davis Dam Grade for a dually one-ton pickup with a gross vehicle weight rating of 13,000 pounds or less.

2011 Heavy-Duty Hurt Locker: Davis Dam Grade Exhaust Brake Test

 Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Davis Dam Grade Exhaust Brake Test

We didn’t just time the trucks up the grade. We also evaluated their exhaust-brake performance while heading back to Bullhead City with the 19,400-pound trailer pushing these dually HDs on their trips downhill.

An exhaust brake saves on brake and transmission wear by clamping down the engine’s turbo vanes, creating back pressure to engine-brake the truck. It also reduces the potential for brake fade during long descents, increasing downhill safety and overall wheel brake life.

The GMC Sierra and Ram 3500 have push-button-activated exhaust brakes that can work in or out of tow/haul mode, while the Ford F-350’s exhaust brake is enabled only when the truck is in tow/haul. Unlike the Duramax and Cummins, the Ford’s exhaust brake can’t be turned off. Cruise control was not used.

Example graph of one of several exhaust brake runs in the Ford F-350 towing 19,400 lbs. (approximately 28,400 lbs. combined weight, including three adult males). Six brake applies can be seen here, immediately after speed peaks exceeded 60 mph. Wheel brakes were applied until speed was reduced to approximately 48 mph, to keep the truck in a narrow band between 50 mph to 60 mph.

At the start, we crested Union Pass westbound and set our speed to 55 mph. Then we waited for gravity to take over and the trucks to exceed 60 mph, at which point we applied the wheel brakes to lower our speed to approximately 48 mph to start the pattern over again. We counted the number of times the wheel brakes were applied. The truck with the fewest brake applies wins.

We’ve always liked the Ram’s exhaust brake, which was designed and engineered by Cummins. During last year’s HD Shootout, we considered it a stronger exhaust brake than the one recently added to the Duramax. That belief proved itself on the downhill run from the top of Highway 68. As measured for the trucks’ best downhill runs, we had to apply the Ram’s wheel brakes only twice to keep the Ram one-ton in the 50 mph to 60 mph range. The GMC Sierra 3500 required four brake applies, and the Ford F-350 required five.

2011 Heavy-Duty Hurt Locker: Eisenhower Pass Climb

Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Eisenhower Pass

Our second major climb was the eastbound ascent from Dillon, Colo., to the top of Eisenhower Pass on Interstate 70, the highest point in the U.S. interstate system. The grade starts at approximately 5 percent for two miles and then increases to about 7 percent for the remaining six miles, to the entrance of the Eisenhower Tunnel — the highest vehicular tunnel in the U.S. It’s perhaps the toughest stretch of road a loaded truck will encounter on a major cross-country highway; we call it the Nürburgring of pickup trucks because nearly every bit of towing and braking hardware is stressed to the max for many miles at a very high altitude.

We started at 8,776 feet in Dillon and finished at 11,000 feet above sea level, climbing 2,224 feet over nearly eight miles and 7,500 feet higher than the finish on Davis Dam Grade.

We drove each truck up the grade in tow/haul mode and two-wheel drive. Runs during which the driver let off the accelerator, braked or both were not counted. The fastest time was used for our comparison. We ran each truck up the grade in sequence, two times total. Each run included five adult males inside, adding another 1,000 pounds to the trucks. The trucks were at a dead stop before each run. The driver ran wide open throttle from start to finish. We didn’t encounter any traffic on the road during the late-night climbs.

Topographical map of Eisenhower Pass based on GPS data collected by our VBOX and exported to Google Earth. The red line representing our timed course up I-70 starts near the upper right, in Dillon, Colo., and finishes 40,000 feet (7.6 miles) later in the lower left, near the entrance to the Eisenhower Tunnels at 11,000 feet above sea level.

Temperatures at the start of the runs in Dillon ranged between 54 degrees and 62 degrees, according to the trucks’ outdoor temperature readouts.

Like the Chevy Silverado 3500 that won the Rumble in the Rockies test, the Duramax-powered GMC Sierra 3500 was the fastest truck up Eisenhower Pass. It finished in 8 minutes, 46.8 seconds – 84 seconds ahead of the F-350 and 152.6 seconds ahead of the Ram 3500. The Sierra’s average speed cruising up to 11,000 feet was 51.70 mph, 7.2 mph faster on average than the Ford and 11.35 mph faster on average than the Ram. The GMC’s top speed was 68.77 mph for a few seconds before the grade changed from 5 percent to 7 percent.

The Ford F-350’s best time up the grade was 10 minutes, 16.6 seconds, at an average speed of 44.51 mph. The top speed was 58.5 mph, and it happened just before the point where the grade increased from 5 percent to 7 percent.

Some may notice that the Ford was much closer to the GMC in performance this time around compared to the Rumble in the Rockies. We noticed that improvement, too, even before we looked at the numbers.

This chart shows each truck's speed climbing Eisenhower Pass against the clock at wide open throttle. The GMC Sierra 3500's fastest run was 526.8 seconds, the Ford F-350's best time was 611.1 seconds and the Ram's quickest climb was 679.4 seconds. The sloped lines represent each truck's position climbing the mountain.

This chart shows the speeds of the three trucks relative to each other over the 40,000 foot (7.6 mile) run to the top of Eisenhower Pass. Note how similar the speed patterns are for each truck as the grade changes throughout the climb.

It seems as if Ford has improved the Power Stroke V-8 diesel’s performance at high altitudes. Last year, we tested a Ford F-450 and an F-350 in the Rocky Mountains, and neither truck was able to exceed 2,100 rpm at wide open throttle up I-70 when towing a heavy trailer. But in this test, we repeatedly saw the Ford hit and hold rpm levels as high as 2,700 rpm – just below its peak horsepower, which is critical for pulling with confidence and strength over long distances. And, in general, driving through the Rockies, without instrumentation running, there were times the Ford Super Duty could pull away (slowly) from the Sierra while climbing grades. If we assigned a ratio to our impressions, the Ford outpowered the GMC about 25 percent of the time in the Rockies while towing.

How was this F-350 able to dig deeper than the other 2011 Super Dutys we’ve driven? We suspect that Ford has continued to refine the Job 2 engine and transmission calibrations (Job 3?) to improve high-altitude performance. We have asked Ford for a comment, but we haven’t received a response as of this writing. We stopped at a Ford dealer in Denver to identify the firmware version, but the service computer only said the firmware did not require an update.

We don’t think Ford submitted a “ringer” for this test. If there’s a firmware update for this truck, you could take your 2011 Super Duty in for service and have it flashed to the same version as this truck. Wherever the change comes from, it’s welcome.


2011 Heavy-Duty Hurt Locker: Eisenhower Pass Exhaust Brake Test

 Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Eisenhower Pass Exhaust Brake Test

We repeated the exhaust brake test on the westbound descent back to Dillon. Eisenhower averages a 2 percent steeper grade than Davis Dam, and that 2 percent made a big difference in slowing the 14-ton fully burdened rigs (trailer, truck and five adult males).

The finishing order changed, with the Sierra requiring five brake applies, the Ram 12 and the Ford 13.

What happened to the Ram? Before we explain, we’ll note that we had both a GM and a Ram engineer in the cab with us (two of the five passengers) during this testing.

If there’s a glaring weak spot with the High Output Ram, it’s the six-speed automatic transmission. The Cummins’ exhaust brake is willing and able to slow the truck, but it doesn’t seem to have the full cooperation and support of the gearbox. By contrast, this is where the GMC’s Duramax and Allison transmission form a formidable team.


By itself, the Duramax exhaust brake doesn’t feel as strong as the Ram’s, but to make up for this, the exhaust brake and transmission work extraordinarily well together. They’ve been engineered that way from the start. The Duramax and Allison downshifted to as low as 2nd gear while the engine stopped burning diesel and only pumped air at 4,150 rpm to slow the truck. The Ram, however, stubbornly stayed in 3rd gear, from 2,500 to 2,900 rpm, and picked up speed until it was forced to upshift to 4th gear to keep from over-revving. Fourth gear, for all the trucks, allowed speeds to increase over 60 mph, forcing us to apply the brakes. If the Ram could have downshifted to 2nd gear, like the Sierra, we think there would have been far fewer brake applies.

The Ford’s weak exhaust brake is its Achilles heel. It had minimal effect slowing the rig and keeping our driver from getting that “white knuckle” feeling you don’t want while barreling down I-70 at night. Although the Ford’s six-speed transmission did a nice job downshifting from 4th to 3rd gear after the foot brake was applied, the wheel brakes on both truck and trailer suffered as stopping power was turned into heat. At the end of every descent from Eisenhower Pass to Dillon, the F-350’s brakes were literally smoking.

Ford has excellent stopping power on flats, but it needs to step up its game in the mountains to stay even with GM and Ram.

2011 Heavy-Duty Hurt Locker: Fuel Economy

 Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Fuel Economy

Our final test of the three heavyweights was fuel economy, because every time you have to stop to refuel, you lose time and money.

We measured fuel consumption over almost 2,000 miles of travel with the trailers behind the trucks the entire time. The results exclude segments where we were testing the trucks, such as on the mountain climbs and at Chrysler’s proving grounds. As we’ve seen in earlier tests, the Ford F-350 had the best fuel economy while towing, at 9.5 mpg. The GMC was close behind at 9.1 mpg, or a difference of $22 over 2,000 miles. The Ram had the worst mileage, at 8.5 mpg, costing $115 more to operate than the Ford.

Download Detailed Mileage Comparison Chart

Ford’s and GMC’s DEF systems – used to scrub nitrogen oxide emissions to meet federal regulations – allow the engines to operate more efficiently with less exhaust gas recirculation than the Ram. While DEF runs about $2.99 a gallon and the Ford and GMC have DEF tanks that hold about 8 gallons, it’s well worth the cost. We started out with full DEF levels in both trucks and never had to refill during the trip, and no low-DEF warnings came on.

Our past measurements show DEF consumption at about 2 percent of diesel fuel, though it might have been higher because of the heavy loads and high stress we were putting on the trucks.

2011 Heavy-Duty Hurt Locker: Best Overall Heavy-Duty Pickup Truck

Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Best Overall Heavy-Duty Summary and Selection

To determine the best overall truck in the Heavy-Duty Hurt Locker comparison, we considered the data we gathered along with our opinions from living with the trucks for a week and driving them more than 2,000 miles.

We also created a two-part chart (below) that summarizes all of the empirical data we collected for each test and turns those results into relative scores based on individual truck performance against the best-performing truck.

For each test — the fastest truck by time or the shortest to stop by distance – first place was awarded 100 points, and the second- and third-place trucks were assigned points relative to how close they finished to the leader. For example, if the fastest truck through the quarter-mile finished in 15 seconds (getting 100 points) and the second-place truck finished in 16 seconds, then the second-place truck received 93 points.

Exhaust brake performance had a significant impact on the final scores.

For your own purposes, you can weight each test section to create your own total score based on the results of our testing.

2011.5 Ram 3500 High Output

The Ram has the most improved interior of any of the trucks we tested and the best exterior, and it has made tremendous strides in powertrain cooling. But despite those efforts, it lags the Ford and GMC HDs.

Inside, the seats were the most comfortable over long distances, and its information display has a good selection of important engine information.

The Ram’s exhaust brake and DEF-free NOx reduction approach are the standout performance features. The High Output 6.7-liter six-cylinder engine is a monster, but paired with the enhanced transmission, it feels the least refined of the group. Only half-jokingly, now that Allison Transmission is fully independent from GM, an Allison gearbox should be paired with the Cummins oil burner. The pair would be unstoppable.

The mandatory 4.10 rear gear set that comes with the Max Tow Package to increase GCWR didn’t help to make this combo feel smooth and well-integrated. We couldn’t help but feel that power was being lost somewhere, slipping away maybe in a torque convertor or clutch plates.

Pricing for this truck was a stretch. The High Output Cummins that is now standard with all Ram HDs with automatic transmissions automatically adds $500 to the window sticker. As equipped, it seemed on the high side for certain options, like the Garmin touch-screen navigation computer, which has an aftermarket feel instead of feeling like it’s factory equipment.

If Ram can continue to improve on its transmission, this truck has the opportunity to seriously rival the other two rigs.

2011 Ford F-350 Super Duty


Integration is probably the most impressive aspect for this truck. The way the transmission shifts is impressive. We love the range select capability in the transmission, but the noticeable absence of exhaust brake effectiveness is troubling, if not unnerving, on big grades. Repeated use of the wheel brakes under heavy load is going to cause issues with long-term wear and cost of ownership. We love the Ford’s rich driver information center. It’s the best trip and truck management computer of the bunch and reflects Ford’s superior ability to make life easier for the Super Duty driver/owner.

Looking under the hood at the 6.7-liter diesel V-8 is confusing. There’s a lot going on because of its unique reverse airflow design, where fresh air comes in through the sides and exits through the engine valley directly into the turbo. We prefer Ford’s DEF solution, with the fuel and urea filler tubes next to each other for easy access when refueling.

For towing, the Ford’s electric mirrors are a huge asset that offers excellent visibility. We also like the in-bed trailer plug and integrated tailgate step. Contrast this with the other two trucks and their bumper-mounted plugs that required us to pull the trailer wire over their tailgates, causing one trailer plug to disconnect and the other trailer wire to pull loose the trailer wire from the junction box on the trailer. We had to bungee cord the GMC and Ram trailer cords to prevent those issues from recurring.

When it comes to performance, we’ve yet to drive a 2011-era Super Duty with the strength and capability of the truck we tested. It was closer in performance to the GMC than we’ve ever seen.

Best Overall Heavy-Duty: 2012 GMC Sierra 3500


The GMC Sierra 3500 is our choice for the Best Overall Heavy-Duty Truck in the Hurt Locker test. Its performance continues to affirm what we’ve seen from previous 2011-12 GM HD pickups. Their chassis and on-road performance should be in the crosshairs of Ram and Ford.

The GMC Sierra led with best-in-class performance, with wins in almost every test we put the trucks through.

The Sierra was the most comfortable rig over our long days. It was also the quickest for the driver to get comfortable with the trailer and load.

We were disappointed with the lack of information displayed in contrast to the other trucks. It needs to get a better information center, yesterday. We’re also disappointed in the solution found for the DEF maintenance. The Sierra needs an accurate DEF gauge — not a low-DEF/empty warning light or an OK indicator. The DEF filler area under the hood next to the engine is awkward, and the tank sits well below the bottom of the doorsill. It’s too exposed, especially if any four-wheel driving is required.

That said, if we were going to shop for a heavy-duty truck today, we’d buy the Sierra.

Go to Part One

*EXCLUSIVE* 2011 Heavy-Duty Hurt Locker (Part I)

Introduction by H. Kent Sundling; www.MrTruck.com

I’ve been privileged to be in 4 of PickupTrucks.com’s truck comparisons. I push to get all the possible tests related to towing of course and Mike Levine goes the extra mile to present accurate data. These pickup truck shootouts become the benchmark for truck comparisons. The largest truck related audiences read this reports. Truck manufactures use the data to improve their trucks with OEM engineers riding with us across the country. It’s a good feeling to be part of an automotive journalist group that can be heard by OEM’s providing our feedback and the feedback of our readers to get trucks designed to meet our needs. As always, there’s enough data in this report for you to pick your winner for the way you use a truck.

This test was designed for maximum use.  Not often can you review trucks at their max limit. We towed 19K plus trailers in 100 degree plus air temp. at 80mph in Utah (legal). We towed extreme grades on desert and the Rockies. Brake tested with loaded trailers, recorded tons of useful data and had no breakdowns or blowouts. Like in real life, we worked long hours, kept our logbooks updated and pushed the trucks to the limit.

 

       
Titan dropped off 3 new 30′ dually trailers stacked on top of each other at Transwest Transwest unstacked the trailers and I towed them to my back yard where the new trucks awaited Rare picture of MrTruck doing manual labor lifting up the ramps for more drag A couple of video crews shot for days and……
       
 …Professional camera dudes were everywhere  Dusk beauty shots, some static, some for…  …Speeding trucks at 90 mph (private track)  Remote camera’s took the dangerous shots

2011 Heavy-Duty Hurt Locker: Truck and Trailer Specs

Part One |  Part Two

Posted by Mike Levine | August 14, 2011

Of all of the trucks we’ve tested in the past decade, the latest heavy-duty pickups seem to have stoked competitive fires and brand rivalries like no others. Not just among enthusiasts, but also among the manufacturers. Every few months, there have been upgraded power levels and capabilities as truck makers have tried to one-up each other.

We created the ultimate comparison test as a complement to last year’s comprehensive Heavy-Duty Shootout and Rumble in the Rockies tests to find out — once and for all — which current heavy-duty pickup is best overall.

It’s a comparison so tough that we call it the Heavy-Duty Hurt Locker.

The Heavy-Duty Hurt Locker is based on lessons learned from previous tests and feedback from readers. It’s a 2,200-mile, four-state slog towing trailers that weigh almost 10 tons each and push each truck’s gross combined weight to more than 90 percent of their gross combined weight rating – levels so high that it forced those of us without one to get commercial driver licenses.

 

*As of Aug-15, 2011, 2012 GMC Sierra 3500HD pricing has not been announced. Test price is estimated.

The Hurt Locker includes driving up two of the nastiest mountain climbs in the U.S. – from hot summer temperatures of more than 100 degrees in the Arizona desert to the oxygen-starved peaks of the Colorado Rockies, 11,000 feet above sea level. Through it all, we measured fuel economy, acceleration, power and braking and evaluated the confidence that each truck gave its driver.

We teamed up with our friends at Diesel Power Magazine and MrTruck.com, and we partnered with Titan Trailers, which supplied the gooseneck trailers, and Pioneer Sand, which provided about 36,000 pounds of ballast.

The Contenders

To push the trucks and their diesel engines to the limit, we decided to test one-ton dual-rear-wheel models from Chrysler, Ford and GM. These rigs can tow and haul more than any other pickup on the road.

2011.5 Ram 3500 with High Output 6.7-liter Cummins I-6

Remember the one-upmanship battles among the manufacturers that we mentioned earlier? This 2011.5 Ram 3500 is the latest example of how quickly the game is changing in the heavy-duty pickup segment. Ram is listed first because it has had the most work done to it.

In response to major power increases from Ford and GM, Ram collaborated with its longtime diesel engine partner at Cummins to boost torque in the inline-six-cylinder from 650 pounds-feet (in early 2011 Ram HD pickups) to 800 pounds-feet for all 2500 and 3500 models equipped with Chrysler’s 68RFE six-speed automatic transmission. That ties Ford’s best-in-class torque rating for the all-new 6.7-liter Power Stroke V-8 Diesel.

To manage that torque increase, upgrades include a new engine control module with new calibrations that allow the engine to achieve peak power at a more desirable rpm range. The Ram’s six-speed gearbox also gets a new torque converter with updated shift calibrations to handle the increased power and a re-engineered crankshaft damper that reduces engine noise and vibration, for improved drivability.

Rams HDs with manual transmissions stick with the standard 350 hp, 650 pounds-feet 6.7-liter Cummins diesel.

 

For Ram dual-rear-wheel models, there’s a new Max Tow option package that features a towing-optimized 4.10 rear axle that includes stronger helical gears and upgraded bearings, along with a finned aluminum differential cover to dissipate heat. There’s also a new water-to-oil transmission cooler and new power-steering cooler to help manage the higher trailer towing ratings.

The Max Tow package increases fifth-wheel towing to a best-in-class 22,750 pounds, up from the previous 18,500 pounds. The GCWR rises to 30,000 pounds in certain models.

The 2011 Ram 3500 wasn’t included in the Rumble in the Rockies because, at the gross combined weights we tested at, we exceeded its 24,500 GCWR by more than 2,500 pounds. Now, in the 2011.5 Ram 3500 we tested, the 4.10 rear axle and Max Tow package added an amazing 8,000 pounds of trailer towing capacity over the standard 3.73 setup. That gave it a GCWR of 29,000 pounds, and a spot in our grudge match. Our Ram test truck was configured as a middle-of-the-road SLT model with the optional Big Horn regional package that adds convenience features and chrome and leather highlights. It also came with a 6.5-inch touch-screen multimedia head unit with Chrysler’s new entry-level Garmin navigation system, Uconnect voice command with Bluetooth and a ParkView backup camera.

Also included was a factory spray-in bedliner, perfect for resisting gradual wear damage from the trailer’s breakaway chains.

In classy Mineral Gray Metallic with sharp-looking 17-inch aluminum wheels and stout styling, the Ram 3500 was the best-looking one-ton we tested, but it was also the most expensive at $58,200.

2012 GMC Sierra 3500 with 6.6-liter Duramax V-8

Although it’s a model year newer than the GM Heavy-Duty pickups we tested in the HD Shootout and Rumble in the Rockies, the GMC Sierra 3500 got only marginal changes, including improved messaging about diesel exhaust fluid levels.

The Sierra 3500’s 6.6-liter Duramax V-8 is rated at 397 horsepower and 765 pounds-feet of torque. For 2011, the Sierra and Chevy Silverado HD pickups got all-new front and rear suspensions, brakes, axles and fully boxed ladder frames. The eight-cylinder Duramax is the fourth generation of GM’s HD diesel. Sixty percent of its hardware is new, and it’s 97 hp and 245 pounds-feet stronger than the original 2001 Duramax. GM says the new diesel engine is 11 percent more fuel efficient than the previous Duramax.

We’re big fans of the Duramax’s performance, as it has proven itself time and again over the past year, but our Fire Red Sierra continues to show its age inside. Like the Ram and Ford, our GMC in the midrange SLE trim had cloth seats, but the controls and colors made it feel stripped down. Black was the dominant color except for Spartan silver brightwork around the gauges, steering wheel and glove box. The rear of the Sierra felt cramped, especially with five adult males packed in during testing in Colorado.

The Sierra lacked running boards, making entry into the cabin more difficult compared with the other two trucks and exposing the large DEF tank hanging off the passenger side under the front door.

Pricing for 2012 GMC HD pickups hasn’t been announced yet, but based on 2011 pricing, we estimate the Sierra we tested would carry an MSRP of $55,710, the lowest of the three.

GMC’s New Best-in-Class Towing and Hauling Ratings for 2012

On Aug. 15, General Motors announced that the 2012 GMC Sierra 3500 and 2012 Chevy Silverado 3500 claim best-in-class towing and hauling among one-ton pickups, continuing the one-upmanship trend that led to this test.

New rear springs, shackles, cargo box mounts and strengthened cargo boxes will enable the Sierra and Silverado HDs to tow up to 23,000 pounds with a fifth-wheel trailer, up from 21,700 pounds in 2011.

Sierra and Silverado will also lead the class in dually payload, with a 7,215-lb. rating for the 3500HD regular cab 6.0-liter V-8 gasser dually.

Finally, upgraded trailer hitch receivers increase conventional towing to 18,000 pounds, up from 17,000 pounds last year. All changes will be on 2012 models arriving in dealerships in the fourth quarter of 2011.

These changes don’t have any impact on the HD Hurt Locker test or its results.

2011 Ford F-350 Super Duty with 6.7-liter Power Stroke V-8


It’s not hard to argue that Ford’s F-Series Super Duty trucks are the benchmarks in the segment when half of the heavy-duty pickups sold in the U.S. have Blue Ovals in their grilles.

During our HD Shootout last year, we didn’t have the Job 2 tune for the 6.7-liter V-8 Power Stroke Diesel. The free powertrain firmware update became available just a few months after the trucks were introduced, and it boosted power and torque ratings from 390 hp and 735 pounds-feet of torque to an astonishing 400 hp and 800 pounds-feet.

This time, like the Rumble in the Rockies, our Super Duty test truck came with the latest engine and transmission calibrations.

The Dark Blue Pearl Metallic F-350 came in the XLT trim, the volume trim of the F-Series lineup. Its interior featured the same high-quality layout we’ve come to appreciate in Ford’s pickups.

The instrument panel came with a high-resolution 4.6-inch productivity screen that provides easy access and rich graphics to provide critical truck data such as fuel economy, driveline and off-road and trailer information. Our biggest gripe with the Super Duty’s interior is that the center stack is packed with buttons that can take drivers’ eyes – and attention – away from the road.

Although each truck we tested had gooseneck hitches, the F-350 was the only truck to offer a factory-installed gooseneck hitch prep package, including bed floor cuts, frame mount and wiring. The hitch ball that sits in the bed is sold separately. For the Ram 3500, it takes about an hour to install a Mopar gooseneck trailer hitch that attaches directly to the frame rails under the bed. The GMC Sierra 3500 requires aftermarket installation of a similar package.

The F-350 was priced in between the other two trucks, with an MSRP of $56,900.

The Trailers and Ballast


Titan Trailer provided us with three brand-new, 30-foot flatbed trailers (24-foot floor and 6-foot dovetail ramps) with gooseneck hitches. Each empty trailer had a curb weight of about 7,100 pounds. The Ruff Neck flatbeds feature tandem dual-rear-wheel 10,000-pound rear axles to support some of the heaviest loads you can tow with a pickup. They also have electric brakes on all four wheels and LED brake lights.

We traveled to Pioneer Sand in Northglenn, Colo. (just outside Denver), where we placed six pallets of earthstone slabs on each trailer. That’s about 12,300 pounds to bring the ballasted weight of each trailer to 19,400 pounds.

That brought the GCWR for the GMC to 27,600 pounds before five adult males jumped in and added another 1,000 pounds, for a grand total of 28,600 pounds, or 98 percent of the Sierra’s GCWR during our hill climb tests.

The total for the Ford F-350 was 28,160 pounds, or 94 percent of the Super Duty’s GCWR.

2011 Heavy-Duty Hurt Locker: Quarter-Mile Loaded

Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Testing

We carefully chose a combination of real-world and closed-course locations to test the trucks. We used our own GPS-based Racelogic VBOX test kit to record performance and geographic data.

A significant part of our testing involved comparing all three trucks head to head at wide open throttle, with and without the heavy trailers. Why would we do that? HD pickups aren’t muscle cars, after all.

At wide open throttle, we can measure the trucks at 100 percent of their maximum power ratings, something we can’t usually do for more than short periods when we’re on extended drive routes over public roads. It’s also one of the only ways to empirically separate the trucks’ performances from each other – which, you’ll see, is measured in the tenths of seconds.

We traveled to Chrysler’s Arizona Proving Grounds (formerly owned by Ford) in Yucca, Ariz., about halfway between Kingman and Lake Havasu City. There, we set up camp on a multiple-acre stretch of flat tarmac. It’s perfect for determining time and speed performance over a fixed distance, unloaded and loaded.

What’s the point of running heavy-duty pickups through the quarter-mile? Isn’t the job of a one-ton rig simply to deliver a heavy load or haul a trailer from Point A to Point B? You’d be correct, except for the one circumstance where the quarter-mile test almost always comes in as a handy measurement: merging into highway traffic.

Acceleration Tests

Because of strong winds, we measured zero-to-50-mph times while towing trailers and zero-to-60 times when the trucks were empty.

There were headwinds from the south gusting 15 mph to 25 mph. To account for this, we ran each truck six times – three sets of back-to-back runs in north and south directions. We averaged each north-south pair to calculate the acceleration times and are presenting the time and speed of the fastest sets.

Weather conditions recorded at Chrysler's Arizona Proving Grounds on July 13, 2011. The blue lines indicates each truck's testing start time.

For all testing, the same driver sat behind the wheel. Traction control was turned on and air conditioning was off, for maximum performance. Tow/haul mode was on when the trucks were loaded and off when they were empty. The exhaust brakes on both the Ram and GM trucks were also enabled when loaded. The Ford’s exhaust brake is automatically enabled when the truck is in tow/haul mode. Towing mirrors were at full extension or in the trailer-towing position when we towed and retracted or folded down when empty. Acceleration runs started by lifting the right foot off the brake pedal and pressing the accelerator instead of holding the brake down to build up engine rpm before launching.

Even though we had three identical new trailers behind the trucks, only one trailer was used for testing to reduce variables.

Towing Trailers

The Ford F-350 was the fastest truck through the quarter-mile when pulling a trailer, but just barely. It ran 1,320 feet in 25.63 seconds at 55.13 mph, almost a quarter-second faster than the GMC Sierra 3500, even though the Sierra finished with a higher speed of 56.75 mph. The speed and time charts show why.

The Ford F-350 carried a higher speed through the first 600 feet before the Sierra 3500 started to outpower it, but by then it was too late. The Sierra couldn’t close the gap between the two, even though the gap was shrinking.

The Ram 3500 demonstrated a consistent pattern throughout all of the acceleration testing, which we could also feel by the seat of our pants. Hitting its peak torque at 100 rpm sooner than its competitors and its 4.10 rear axle helped give the Ram fast starts off the line – usually first or second through the first 400 feet – but its lack of horsepower seemed to hurt the Ram over the full quarter-mile. It finished the distance in 26.39 seconds at 53.46 mph. Overall, the Ram stuck very close to the Ford and GMC one-tons.

The Ford Super Duty’s coolant temps ranged between 208 and 219 degrees, and transmission temps hovered around 207. The F-350’s transmission was able to shift to 4th gear, finishing the runs at about 2,900 rpm, about 100 rpm above peak horsepower. We didn’t encounter any rear axle hop like we have in the past, but we could feel a surge of power move from the front of the truck to the rear as it launched in wide open throttle. In general, the Super Duty’s six-speed had the smoothest shifts of the trucks – something we also saw in performance tests and highway driving.

The Sierra’s coolant temp stayed a consistent 210 degrees while transmission temperatures rose from 158 on the first run to 189 at the end of the third. A cooling fan kicked in whenever coolant went above 210 degrees until that target temp was reached. The Sierra held onto 1st gear the longest of the trucks, holding it until 3,000 rpm before upshifting to 2nd. It was the only truck that made it to 5th gear at the quarter-mile mark, upshifting at 3,200 rpm in 4th and immediately dropping to 2,300 rpm in 5th.

The Ram HD’s coolant ranged between 204 and 222 degrees, but the truck’s fan turned on in the low 220s and efficiently lowered the temperature to 210 in a few moments. Gearbox heat ranged from 199 degrees during the first run to 215 after the last. In general, rpm numbers from the Ram’s inline-six were lower than its eight-cylinder competitors. The Ram made it to 4th gear in the quarter-mile. There were occasional hard upshifts.

2011 Heavy-Duty Hurt Locker: Quarter-Mile Unloaded

Words by Mike Levine, Mark Williams and Kent Sundling, Photos by Ian Merritt

Unloaded Acceleration Tests

The only time our trucks were unloaded was during the quarter-mile testing at Chrysler’s proving grounds.

Free of its burden, the Sierra ran the fastest sprint, finishing with a best time of 17.22 seconds at 84.97 mph – about 8.5 seconds and almost 30 mph faster than when it was towing. The Ford F-350 was right behind it, finishing in 17.56 seconds at 83.03 mph.

Again, the Ram was close behind, running the quarter-mile in 18.02 seconds at 79.94 mph.

All three one-tons were within 2 mph and less than a second of the times we measured for similar one-ton trucks in the 2010 Heavy-Duty Shotoout.

 

Of course, the trucks ran cooler without the Titan trailers hanging off their backs.

Coolant temperatures for the F-350 dropped from 219 degrees to 206 degrees, and the transmission hovered around 203. The F-350 finished each run in 5th gear, and because we stayed at wide open throttle for several hundred feet after the quarter-mile mark to ensure clean data capture, the engine revved as high as 3,100 rpm, and fuel cutoff occurred at just over 90 mph. In one run, we felt the Ford’s traction control intervene at the start of the sprint and cut engine power.

Temperatures didn’t vary much for the Sierra after we unhitched the trailer. Coolant remained around 210 degrees, and transmission temps stayed around 183. Without the gooseneck, the GMC was able to shift all the way to 6th gear (with the wind at its back) and hit more than 90 mph past the quarter-mile marker. During all the wide-open-throttle runs, shifts from the Allison gearbox were smoother, though we noticed some torque converter slip between 2nd and 3rd gear.

We’ll note that we encountered a terrible buzzing/vibrating noise coming from the Sierra’s engine compartment during hard pulls on the highway and at the proving grounds when the engine was running between 2,300 rpm and 2,800 rpm. It turned out to be a relatively common problem for 2011 Duramax owners, caused by the position of the heater hose that runs from the exhaust gas recirculation cooler to the heater core. After we repositioned the hose with a zip tie, the noise immediately disappeared. GM dealers are aware of the problem, and a production fix will be implemented soon to prevent it in new trucks, GMC says.

The Ram ran much cooler without the trailer. Coolant temperature never exceeded 206 degrees, and transmission temperatures stayed below 200. With tow/haul off, the shifts seemed smoother, and they became closely spaced. The Ram shifted all the way to 6th gear in the quarter-mile. The 2-3-4 upshifts were particularly smooth and well-cadenced. Each new gear started at 2,500 rpm and upshifted at 3,000 rpm like clockwork. There was some torque converter slip that caused a slight rpm drop between 4th and 5th gears.

Go To Part Two