just got a 2005 5.9 cummins. i also have a 1993 12v cummins. i have unlimited resource to 2 cycle oil and was wondering if adding a certain amount to either truck at fill up will help mpg or engine life? also what are a list of mods i can do to the 2005 and 1993 to improve mpg? also both trucks are stock. thanks!

 

smarty jr, intake, exhaust

 

the 12 valve I'm not sure about but the 05 would love to have a quart per fill up to keep the injectors lubed better. I add a quart usually every other fill up or sometimes every 3rd fill up. If I had an unlimited supply I would do a quart every tank!!

 

had lots of mixed reviews on 2cycle oil in fuel? just making sure before i add anything and make problems for myself thanks for input!

 

I've used PowerService fuel treatment every fill up since day one on my '03. Closing in on 300k miles and several thousands of hours of engine run time and, knock on wood, my factory stix still provide good fuel economy and a very smooth idle.

just my .02