Power or Torque?
I won't talk about the MPG advantages since that is obvious - but which is more important to you in a truck? Horsepower or torque? The V8 HP rating is much higher than the V6 diesel, but the diesel torque curve is very fat which makes that energy available immediately even at the low RPM ranges. The max HP rating of an engine (gas or diesel) is usually found near the max RPM limits of the engine. You really have to compare torque curves to see the "feel in the pants". In a drag race, the diesel is a goner because it runs out of breath at the higher RPMs (hear those semi drivers shifting 10 times just to cross the intersection?) but for hauling loads, the V6 diesel is as good or better than the V8. Diesels also retain closer to their gas mileage figures under heavy load conditions than gas engines. So if your needs are for hauling a lot of people/stuff/towing, and not necessarily for beating the next guy to the stop light, the diesel is the better choice. I drove a GL320 CDI and the passing power is amazing. Could not believe it was a 3.2 liter V6 moving nearly 6000 lbs.
Last edited by cyeung65; Jan 26, 2007 at 08:36 AM.