I have a 1999 Ram 2500 with a 5.9L V8 5-speed. When living in the St. Louis area, I was getting 15-16mpg on a regular basis. Since then I have moved to Wyoming, I struggle to get 13mpg. I have changed the air filter, tried higher octane fuel, and run injector cleaner every 3000 miles. I have even tried driving slower!!! My only other thought was the higher elevation, but the mechanics with whom I have talked to out here says that doesn't matter.

Any thoughts or ideas would be appreciated.

 

Here is was I tell my customers-you should be getting at least 12-13MPG. That is what they get, if you happen to get more, good for you. If you get less, have it looked at. If you get 12-13, that is pretty much what the rest og the world is getting, I know somebody is gonna claim to get 20MPG-whatever. I've owned 3, my dads had 2 I've been working on them for a decade. Magnum V8's get 12-13, also summer grade fuels get worse mileage than winter grade.

 

I get 12 - 15 in town (depending on how I drive) and 20 on the highway in my 02 4.7 1500 QC.

Its a big 7000 pound brick that you are pushing through the air...you get what you get.