I have a 2008 Ram 4wd with 5.7 engine. Lately I've noticed that there seems to be a very mild miss occassionally while driving it. The truck got a complete dealer tune-up in Jan '10. The mpg has dropped off about 3-4 mpg. There are no check engine light codes on,the air filter is clean. I'm about to change the oil,check tire pressure and see if my brakes are dragging any. Any other ideas of what problem could be? Thanks for any advice.

 

Did the tune up include a removal and cleaning of the throttle body? They almost never do, and it's a pretty good mpg robber (although not 3-4 mpg). How many miles on the truck?

 

Welcome to the site

 

It has 74,900 miles. I was using the crappy Murphy USA (Walmart) gas too the last couple tanks when I noticed the poor mpg. I switched back to Shell today, my tires were 10 lbs under on 3 outta 4 tires. I'm gonna change my oil now. I will check and see if throttle bottle cleaning is part of tune-up. Thx. What about o2 sensor,would i have check engine light if that was problem?

 

Thx, good site.

 

new O2s can help. IDK what their mileage expectations are honestly. I just replaced mine and Im at 80k +/-