You can't go by your computer, for accurate mileage.

 

My overhead trip computer(lie-o-meter) is consistently 2-3mpg off!

 

When i'm on te highway.. I set the cruise at 70... i need to.. i have a heavy foot... But anyways.... My so called estimater... says i'm gettin atleat 17.5 highway.. and YES... i do reset it... and that with more uphilll then downhills..

 

for best mileage, don't go over 55mph. keep the rpms below 2000, 1500 is best, you will be amazed how good thease hemis are, now if your worried abought growing old before you get thier, don't excead 65 mph, best of booth worlds.

reseting the trip/mileage coumputer every time is not that dependable, it dose have a pyschcological perk when you watch the mileage numbers go up and allways start with a full tank and run it dry, you get better milage than adding gas here and thier as you go.

 

I-40 between Oklahoma up until Virginia is almost all 70mph speed limit. There are areas in OK that are 75 mph, up around Tulsa IIRC.

I bought my truck ('05 QC 4x4 Sport package) in PA when we were home on leave. I immediately put a bedcover on it to keep our bags dry on the way back to Little Rock, AR, so I don't have any data without the cover on it. After about a 500 mile break in, I reset the trip computer for the way home. With the cruise set at about 72 mph I get 17 mpg. I haven't done manual calculations, but I don't believe I've gotten over 17 mpg on the highway.
When the truck was stock, I tried to keep it below 2,000 rpm for gas mileage purposes. Since I put the exhaust on it, though, I have to keep it under 2k in order to keep my hearing!!!!

 

If your overhead trip computer MPG average is consistently far off the actual...say over an average of 5-10 tanks...that is a strong hint that some of your fuel injectors are clogged, or your fuel pressure is dropping because of pump/regulator/filter troubles.

 

WOW[sm=yikesomg.gif]rpmorey ... 15 towing a 5k TT ... Daaaaaaaaaammmmmmmmmmmmnnnnnnnnnnnn !!

06 Mega dont come wiff MDS ... best I get is 8.5