Does anyone know why I get such bad gas mileage? Overall gas mileage on my overhead is 11.4mpg average. When I first got the truck(about a year ago)it had the Mopar Computer in it and was only getting 9mpg then I put the stock computer back in and programmed the Hypertech.People have told me that it's my tire size and I should re gear but I really don't want to spend the money to re gear it. Thanks

 

what gears do you have now? my truck gets 21mpg with 31" and 3.55 gears.

when was the last time you did a tune up. that helped mine alot. and when my O2 sensor went I dropped down to like 15mpg.

if you have 3.55 I would go to 4.10 if you dont do alot of highway driving.

 

i am also getting 21-22 MPG on the freeway with 31" tires and the 4x4. im sure your lift/tires is killing your mileage but you should still get better then that. check your tire pressure and answer jonny's question about the tuneup

 

i get 18 if i baby my truck. its impossible for me to get more. i average 16 mpg 31x10.50 tires and 3.55 rear end. how do you guys get 21-22. and yesi already had my spedometer/ odometer recalibrated.

 

Tell me about it how do you guys get 21-22 per gallon i know i have a V6 but my dads 4.7 doesnt even get that good i think the best it got was 17-18, but thats is if you baby itbut who babies a v8 lol

 

the main thing to get a good mpg is to keep up the maintenance on it. keep the tires at the right psi, change plugs, oil etc...

I hardly every baby mine with a light foot cause I love to hear the exhaust.and I still get around 20 doing that.

I replace all my fluids with synthetic. thats all I run now. I bet I could get 22+ if I babied it and never stomped on it. but thats not gonna happen. if I get 18+ im happy. my truck has 205,000kms and sill goin strong.

 

your cat might be getting plugged. also check and see, someone might be stealing gas from you. tire pressure is a sure sign to better mileage. also if you are running a 6 banger with those tires, gearing is the only thing that will help.

 

My truck does mostly all highway driving. I haven't done a tune up yet. It's a 99 and I only have 64k miles on it. I've had it for about a year and average only725 miles a month.I do keep my tire psi where it should be. I guess it kinda sucks cause other people have 33's and get better gas mileage. If I could get 15mpg I would be happy. It's been getting worst since it's cold out, today my gas light came on and I only got 170 miles to the tank.

 

Yea my 3.9 gets 15 on good days

 

yes other people get better with 33's but you have 33x13.50 not 33x12.50 which is the most common. and the wider the tire the more air resistance and drag you have.