Engine Torque Specs

The torque specifications for an engine are a measurement of its output power at peak rotations per minute (RPM). The engine's peak RPM will depend on its make and design, but most diesel engines in smaller vehicles have peak RPM in the 1,500 to 2,000 RPM range.

This "peak" is when the engine is most efficiently using fuel for the amount of power (in terms of rotations and torque) it is producing. The torque at this point is the defining measure most knowledgeable people in automotive will measure the true strength of the engine in terms of how much weight it can move.

A Dodge Ram 2500 with a 6.7L V6 Cummins diesel engine, for instance, outputs 650 foot pounds of torque at 1,500RPM (it's peak). It's displacement of 6,690 cubic centimeters is relatively large compared to other light truck diesels.

A Chevrolet 3500HD with a 6.6L V8 Duramax puts out 660ft-lb of torque at 1,600RPM and displaces 6,601cc while a Ford F250 with a Super Duty diesel at 6.4L (V8) outputs 650lb-ft of torque at 2,000RPM with only a 6,400cc displacement.

For the most part, the smaller the displacement, the lower the fuel consumption overall. Vehicle manufacturers are often working to improve the balance between displacement and power output.

Most smaller diesel engines, such as those found in the extremely efficient Audi Q7 TDI Premium Quattro, will displace around 3,000cc (2,967cc for the Audi) and produce about 400lb-ft of torque at peak RPM. This Audi is capable of well over 40mpg on the highway.

A typical gasoline engine putting out that much power would likely get about half to two thirds of the fuel efficiency as the Audi's output is on par with many consumer sports cars.

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