I have a 2000 2500 Cummins 2wd with an auto tranny. It has bout 119000 on it and I only get like 14 miles a gallon that I fugured out once, they were mostly highway. I tried drew's brews and changed my fuel filter and it increased bout at least a mile a gallon. I have stock air box and stock exhaust on it for now. Gonna replace muffler with pipe but keep cat for some back pressure and put an after market filter. Are there things I can get for it or things to do for that will increase the gas mileage a good amount. Are they any affordable chips that will help it out.

Thanks

 

Load it down heavy and take it on a long ride, helped mine out, because the guy who owned it the first 26000 didn't load it, I was bitching about the fuel mileage the first four days I owned it, but then when I hooked my trailer to it and hit the road to so a job and put in 180 miles for the day, I noticed it started getting better with in a few days

 

I guess that would like kinda clean the engine out

 

also find a big hill and lay into the throttle the whole way up. this will get the EGT's and cylinder pressures up and burn off an carbon buildup on the injectors.