I purchased a '02 GMC 2500 w/ approx. 90,000 miles several months ago. I went for my first trip of any length, pulling a 30' fithwheel camper, last week. I left home with a tank full of the same fuel I use in my tractors, high sulfur and 2% soy oil, had all the power I needed. Filled up shortly before reaching my destination. I spent the trip home listening to it jump out of overdrive every time I wasn't going down hill. Same roads, wind wasn't a factor, air and fuel filters changed a month ago. Could the power difference have been in the fuel alone?

I haven't had the opportunity to use any bio yet, but it's been said around here that they run better while using it. If all else was the same, it's a pretty good indication that it somehow must have been the fuel. Out of curiousity, where do you get "high sulphur" fuel? I thought that all one could get was low sulphur.

The fuel is meant for off road farm and constuction use only, it slipped in the tank by mistake.;)

I've run red before and found a big difference in fuel mileage, with red being the better one.

I've run red before and found a big difference in fuel mileage, with red being the better one.

How much of a difference? :confused:

Ben

The fuel is meant for off road farm and constuction use only, it slipped in the tank by mistake.;)

I thought that the only difference between the off road and other was the red dye and the road tax. I guess I didn't realize that the fuels were different; I thought all the fuel was low sulphur.