Just thoughts I'd share the info....

The solar system lined up just perfectly where I had three identical 600 mile round trip runs from Tucson to El Paso with no load or trailer, so I decided to try out two DFAs. I fueled up at the same stations each time.

The first trip I ran straight pump fuel with no DFA of any kind.
75-80mph cruise speed (Tucson-El Paso) net 15.1 mpg
60-65 mph cruise speed (El Paso-Tucson) net 18.8 mpg

Second trip with Shell Rotella DFA.
75-80 mph cruise speed (Tucson-El Paso) net 15.5 mpg
60-65 mph cruise speed (El Paso-Tucson) net 19.8 mpg

Third trip with Diesel Kleen (grey bottle)
85-93 mph cruise speed (Tucson-El Paso) net 16.0 mpg
60-65 mph cruise speed (El Paso-Tucson) net 21.0 mpg


The last trip was pretty quick going out, I shouldn't have been driving so fast, it was just that the truck seemed to be running very well that it was hard to stay out of the throttle. There was a VERY strong headwind most of the way to El Paso, so I had to keep my foot in it to keep up the speed. Then the wind would die down for a bit and I would peek at my speed and it was stuck at 93 mph. I guess that's the fastest the truck will go.

Anyway, I think I'm sold on the Diesel Kleen product. ($10.99 per 96 oz at Flying J Truck Stop) About 3 mpg better fuel economy, easier starts, smoother engine and more power. Pretty cool stuff!