Duramax vs Power Stroke Fuel Economy Tow Test and Drag Race

FishOnOne wrote:

4x4ord wrote:
The problem with doing mileage tests over a short distance like this is that if during the test the Duramax happened to do a DPF regeneration and the Ford didn't the results are meaningless. I think it takes roughly a gallon of fuel to clean the DPF so on a run where only a few gallons of diesel is required the mileage result could be way off.

I thought about that but if a truck did do a regen I think the mpg delta between these two trucks would have been greater. Plus towing this much weight there should have been passive regen working in their favor.

in colder weather my truck will go a long ways before the DPF is full but on average I'm going to guess it cleans about once every 500 miles. All it would take to screw up the test is for a regeneration to be triggered anytime in that short test loop. If the Duramax happened to start a regen even 5 miles before the end of the test, the test is flawed. To really do a proper comparison they would have to run both trucks an entire cycle; start with a clean filter and end with a clean filter. Then calculate miles per gallon based on the distance travelled even though it would be a different distance for each truck. Is it possible one truck regenerates 30% more often than the other or that one uses more fuel to do its burn? I might put quite a bit of emphasis on fuel economy when making a truck purchase if I felt the fuel economy tests were accurate.... as it is I think I would purchase the truck I wanted and if it happened to be the one that got the best fuel economy during the comparison, I would feel a little better about my choice.