Chevy vs. Ford, Duramax vs. Power Stroke, and Allison vs. TorqShift—these are brand battles that never get old. In fact, for the 2011 model year, they’ve all been reignited!
Face it, when it comes to diesel pickups, we all want the one that makes the most power. And for the first time in years, Ford Motor Company and General Motors offer similarly sized diesel V-8s that are rated to within 3 hp of each other. This horsepower and torque war has been great for our industry, but we want to know which truck does the most with its power. Loyalists and diesel enthusiasts are quickly choosing sides. Ford and GM have launched major ad campaigns touting their trucks as “the most powerful,” and even the Internet forums are buzzing with diesel bench racers. It’s time Diesel Power settled this feud. So we again teamed up with PickupTrucks.com's Mike Levine to test the latest diesel heavy-duty trucks Ford and GM offer.
Ford vs. Chevy: Round One Recap
After our initial testing of each manufacturer’s ¾-ton and 1-ton trucks (“2011 Diesel Truck Shootout,” Oct. ’10) with PickupTrucks.com, Ford released a high-output version of its 6.7L Power Stroke. The power increase bumped the engine’s output by 10 hp and 65 lb-ft—giving it 3 more horsepower and 35 more lb-ft of torque than GM’s 397hp and 765-lb-ft LML Duramax.
We knew that meant a Silverado vs. Super Duty rematch—but not just any rematch. This time we set out to find which manufacturer builds the most powerful pickup by taking each truck over one of the toughest tows in America, with a gross combined vehicle weight (GCVW) approaching 28,000 pounds.
We'll give you the full story in the February , 2011 issue of Diesel Power magazine (on sale January 1, 2011), but with a battle this powerful, we couldn't keep the results to ourselves for another second!
11,000-Foot, 18,900-Pound Towing Torture Test
The stretch of Interstate 70 that spans across Colorado is one of the most intimidating highways in the country. Nearly six months out of the year you can expect dismal weather conditions, freezing temperatures, and trucks moving very slow along the section that connects Denver to Grand Junction. Mountain peaks can reach higher than 13,000 feet, and the highway itself climbs to more than 11,000 feet at the Eisenhower Tunnel—what a perfect place for a diesel truck test.
The Combatants: Ford F-350 Super Duty vs. Chevy Silverado 3500
Ford and Chevy were both asked to provide us with a production truck straight off a dealer’s lot. Unfortunately, Ford declined to supply us a vehicle for this test. So, General Motors purchased both 1-tons involved in our 2011 King Of The Hill Shootout from Midwest auto dealers.
The two crew cabs in our test were ordered with four-wheel drive, 3.73:1 axle gears, 17-inch wheels (the Ford’s are forged aluminum vs. Chevy’s steel units with chrome inserts), and cloth interior. Navigation systems, cooled seats, and other luxuries were purposely left out. The trucks were so evenly matched that even the prices of both rigs were nearly identical. The MSRP on the Ford sticker was just $65 more than the Chevy’s.
Upon weigh-in (with both trucks full of fuel), we noticed the Ford was only 200 pounds heavier than the Chevy—making for a pretty even matchup. In fact, in the years this staff has been conducting vehicle shootouts, we’ve never seen such evenly matched trucks.
For those of you saying, “Hey, wait a minute. If GM gave you both trucks, that stacks this test in GM’s favor.” We thought of that, too. We decided the best way to offset this perceived advantage was to hire a former Ford Motor company engineer to drive both trucks during all of our testing. Our driver’s name is Harry Rawlins, and he was previously Ford’s Trailer Tow Engineer. Holding that job title meant Rawlins was intimately familiar with Ford’s (as well as GM’s and Dodge’s) towing capabilities. Rawlins also holds a Class A commercial driver’s license (CDL), which meant he was the only person in the test legally able to drive the trucks towing this much weight. Plus, in the sense of full disclosure, Rawlins is also a Super Duty owner.
Upping the ante this time, we pitted the two comparably equipped Chevy and Ford dualies against each other, and each truck took turns pulling a 30-foot-long, 18,900-pound gooseneck trailer over our real-world test course. Our 25-mile test loop consisted of an 8-mile eastbound climb up I-70 from Dillon, Colorado. The climb begins as a 5-percent grade and transitions into a 7-percent killer. The starting line for each truck began at 9,200 feet and ended at the Eisenhower Tunnel at 11,000 feet. At that point, we’d turn around on the east end of the tunnel and descend back down the western slope of westbound I-70 to evaluate each truck’s exhaust brake and tow-haul mode. The testing was performed at midnight, when traffic on I-70 is practically nonexistent. The ambient air temperature ranged between 5 and 11 degrees F. The test began and ended at the Dillon exit.
Acceleration Test: 6.7L Power Stroke vs. 6.6L Duramax
The trucks were tested one at a time, launched in four-wheel drive (for best traction), and returned to two-wheel drive at 30 mph. Both trucks were held at wide-open throttle for the entire 8-mile climb. All tests were recorded by one of Racelogic’s VBOX GPS data loggers for the most accurate data possible. Quarter-mile, 0 to 50 mph, and top speed were all measured in addition to the one-way elapsed times.
Exhaust Brake Test: Holding Back 28,000 Pounds
Each truck was then turned around at the top of the hill and driven westbound back through the tunnel. The trucks exited the Eisenhower Tunnel at 50 mph, with their exhaust brakes and tow-haul modes turned on, and the transmissions in a manually selected Third gear. The trucks were then allowed to descend from 11,000 feet to 9,200 feet so we could determine how well each of them could control the 18,900-pound trailer.
After our initial ’11-model-year-truck testing last summer in Michigan, we were left wondering how the high-output (400 hp) version of the new 6.7L Power Stroke would have faired against the 397hp 6.6L LML Duramax. Surely with 800 lb-ft of torque, the new Super Duty should give the 765-lb-ft Duramax a run for its money in a test of power, right?
Nope. It wasn’t even close.
Once again, the Chevy proved to be the superior performer when it comes to acceleration testing. In every towing test we ran on I-70, the Silverado 3500 outperformed the Super Duty F-350. The Silverado made it through the quarter-mile more than 2 seconds quicker, achieved a top speed that was nearly 10 mph faster, and finished the entire climb more than 2 minutes ahead of the Ford. The Duramax performed significantly better at 11,000 feet of elevation as well, pulling the 18,900-pound load at 47 mph, while the Ford slowed to 35 mph. Check out our acceleration testing sidebars for the full results. Acceleration Test Winner: Chevrolet Silverado 3500
The exhaust brake test brought out similar success for the Duramax and Allison combo. As we began our downhill run, the Ford descended the western slope well but required an average of 14 applications of the truck’s brake pedal to hold the vehicle speed between 50 and 60 mph. The exhaust brake was clearly working, but the nearly 28,000 pounds (with four people in the truck) was more than the Ford could control without driver input.
The Chevy on the other hand, crested the top of the hill feeling like a totally different kind of vehicle. Just by the exhaust noise we could tell the Duramax’s Garrett turbo offered far more exhaust braking than the Garrett unit the Power Stroke uses. Going downhill in the Chevy, the driver had far less work to do. While the Super Duty managed the load by hitting the brakes 14 times, the Chevy only required 1 brake application for the entire 8-mile downhill run. While the difference in hillclimbing between the Chevy and the Ford is impressive, the exhaust braking advantage of the Silverado is staggering. Exhaust Brake Test Winner: Chevrolet Silverado 3500
Before the tow test began, we drove both trucks 1,250 miles out to Colorado from Detroit. This served as both an initial break-in process, and a fuel economy challenge for the two trucks. Thanks to the fact that a majority of the miles accumulated were in light traffic and on flat ground along I-94, I-80, and I-76, we were able to see what kind of mileage these trucks can achieve out on the open road. Cruising speeds were kept between 65 to 80 mph the entire trip, and drivers swapped trucks at each fuel fill-up.
We found that both trucks were comparable in the mileage department, with the Chevy edging the Ford by less than 0.7 mpg. See our fuel economy side bar in the February 2011 issue of Diesel Power for a complete analysis. Fuel Economy Test Winner: Tie
Be sure to check out the full story with all the data and details--as well as our analysis on why the Ford lost-- in the February 2011 issue of Diesel Power magazine. It'll hit your mailbox, and newsstands, on January 1, 2011. And you can see the data from our test at Pickuptrucks.com