Red Line 85 Plus Diesel Fuel Additive Treatment - 12 Ounce, Pack of 12

I did not se any increse in mpg, but using it gives me peace of mind that my fuel is lubricated enough, and it is keeping the injectors cleener.

This stuff actually works. I have a new 2007 Duramax with only 5000 miles. I put in the additive and the truck ran quieter with an increase of 1.5-2 miles per gallon. Well worth the money when fuel is $4.75 a gallon.