Info from Pickuptruck.com

[Wrenchtraveller]

Gas Versus Diesel Comparison By Brand - 7% Grade with Trailer

This page is an opportunity to compare the relative performance of the single rear wheel gas pickups against their dual rear wheel diesel counterparts on the 7% grade.

Obviously, not an apples to apples comparison (primarily because of weight and rear axle and rear track differences between the 3/4-ton and 1-tons), but it provides some indication of the scenarios where each type of engine excels. You can see the patterns from manufacturer to manufacturer are almost identical, regardless of the truck / engine / transmission combinations.

Again, as we noted during the level 1/4-miles at Milan and MPG, look at how close the time and speed curves are for the Ford trucks. They were near identical up the 7% grade. In contrast to the Dodge and GM oil burners, the 6.8-liter V10 gas engine was faster moving up the grade than the 6.4-liter V8 diesel.

We'll raise the question again - with performance numbers like these, if you're not going to hold onto your Power Stroke for more than 100,000-miles do you really need to pay a $6,000+ premium for the diesel option over the gas V10 Triton's power and capability?

Pickuptruck.com has all the graphs showing on 7% diesel grade pulls with 10500 pound trailers, GMC was first, Dodge was second, and Ford's 6.4 was the slowest diesel.

[richfaa]

Hummmm..We have the 05 V-10 and have pulled many 7% grades dragging the 3400 behind. I have stated many times as of late that I think the gap between gas and Diesel is narrowing..however I find those numbers very hard to believe. The diesel is outstanding in the power department and I would not bet my hard earned money that my V-10 could out pull a Diesel up a 7% grade.At least I have never been able to keep up with them as of yet.....Close..but no cigar..

[sreigle]

They also have diesel and gas tests on 15% grades in that article. And the F450 with the 6.4L diesel towed a 20,000 lb trailer up a 25% grade in that test, also. On the one ton diesel results they show the Duramax coming out slightly ahead. But then conclude that all are so close that any will do the job just fine.