I have an 08 Ram with 5.7 hemi, its got 80000 miles on it. I put the new correct Champion plugs in it,the air filter is clean and had the dealer do fuel injector cleaning. Tire pressure is good. I'm getting 12 mpg in town and highway mixed, was gettin about 16 when i got it yr and half ago. Any idea guys?

 

When was the last time the throttle body was cleaned?

 

It had complete dealer tune-up at 50,000. Don't know if they clean it with those or not, but I'll call and see. You think thats the problem?

 

It can contribute. Still, 12 mpg ain't too bad. 16 mpg in town sounds like the computer talking, not the real world.

 

Never heard of anyone getting 16 in and around the city. 12 is about accurate. Reset ur mpg computer while u r city driving and then do it again while ur on the hiway. That will prob give u a more accurate live #. The average is just both over time, good days and bad.

 

I said 12 mpg city and highway mixed, meaning i fill the tank up and do my usual driving , which is a combination of both city and highway driving. About 1/8 tank left, I refill it and check it by calculator. I dont pay any attention to the computer mpg, it always lies. It use to get 16 mpg w/mixed driving, but now its getting about 12. I run Shell 87 octane gas. Any ideas now?

 

I know what u meant. I still think 12 to14 combined is fair, thats taking it easy. I run 89 all the time. That is until this week when my programmer comes in.

 

2wd is rated at 13 city/19 hwy.
4wd is rated at 12 city/18 hwy.

You are not far off base.

 

in that year did you get new tires? HAve you changed the differential fluids? Maybe the quality of gas is worse now. I get a solid 13-13.5 in town. Cant wait to see what I get with a SC and 91!

 

The ethanol in gas now days is probably the main factor in the drop that being said cleaning your tb and egr would help also clean or replace your o2 sensors would be another idea