2017 3/4-Ton Premium Truck Challenge: Diesels on the Dyno
For those who tow (or intend to), haul heavy loads (or intend to) or need to do both while carrying family members on vacation (or intend to), the three-quarter-ton pickup truck can be a perfect choice. And in the world of full-size fully loaded 4×4 diesels, the single most important feature in this kind of vehicle is what's under the hood.
In fact, many customers in this segment choose their engine before choosing their pickup. That's how important an engine can be. To shine some light on the differing characteristics of each of the turbo-diesel engines in our 2017 3/4-Ton Premium Truck Challenge, we put them on a chassis dynamometer to see how they perform.
What does a dyno test tell us? It provides the opportunity to see — in an apples-to-apples comparison — how these different power plants create and distribute their strength.
How They Compare
Given the diversity of engines in this Challenge, it's no surprise our dyno results varied widely. The burly straight-six Cummins in the 2017 Ram 2500 made more than 95 percent of its torque around 2,000 rpm. The 2017 Nissan Titan XD, with the newest and smallest turbo-diesel of these heavy-duty trucks, uses a dual overhead cam V-8 Cummins and made its peak torque around 3,250 rpm. But it was the Duramax in the 2017 Chevrolet Silverado 2500 and Power Stroke in the 2017 Ford Super Duty F-250 that were the most alike and the most powerful. They have relatively similar architectures, and that's where the main battle for three-quarter-ton supremacy takes place. We saw that at the and during our when towing gooseneck trailers, but in the dyno testing we saw, the numerical representation.
The Chevrolet and Ford 32-valve V-8 engines were newly reconstructed for model-year 2017 to squeeze out as much power and torque as possible. They use high-pressure common-rail direct fuel injection, have similar compression ratios and have huge improvements in cooling power. Using the factory numbers, the Chevy Duramax has a 5-horsepower advantage over the Ford Power Stroke, while the Power Stroke has a torque advantage of 15 pounds-feet.
Here's what we found when we put each of our competitors on the dyno at Arizona Dyno Chip in Tempe, Ariz.
Power to the Rear Wheels
The Chevy's all-new turbo-diesel 6.6-liter V-8 Duramax made the most horsepower and torque of our four players, recording 385 peak hp and 775 pounds-feet of torque on the chassis dyno. This was just slightly ahead of the Ford's 6.7-liter V-8 Power Stroke, which made 369 hp and 721 pounds-feet of torque. Ram's 6.7-liter inline-six-cylinder Cummins came in third with 332 hp at 2,700 rpm, and 663 pounds-feet of torque at 2,200 rpm. The Nissan's 5.0-liter V-8 – the smallest engine of the group — came in last, making 267 hp and 437 pounds-feet of torque.
How We Conducted the Testing
Anyone who has experience with a chassis dynamometer knows it can be a little tricky capturing peak performance, mainly because of how smart (and dumb) many new transmissions (and the software that controls them) can be. Thankfully, we are familiar with Arizona Dyno Chip, so we made a date to test all our trucks on the same day, with the same technician, following the same procedures. Doing so allowed us to feel confident about the results of our dyno testing.
Cars.com photos by Angela Conners
| | Towing | Daily Driving | Dynamometer Testing |
