2000 wrangler 4.0L, auto, 31" tires. seems to be getting about 11 mpg. i try not to go over about 55mph and am on highway about half time. RPM are about 2500 at 55mph. How much do the bigger tires affect the speedo and the odometer? I guess my figures could be off a bit but i would expect closer to 15-17 mpg. i counted the drive shaft at just over 3 revolutions for 1 revolution on rear tires. thanks
low MPG?
- Thread starter johnoz28
- Start date
I have the same setup - 2005, 4.0L auto and 31s. I keep pretty detailed records of my gas milage, and I end up pulling 13.5 MPG - 70% city and 30% highway.
Got enough air in your tires? You may try some fresh spark plugs. A cold air intake can help as well.
Got enough air in your tires? You may try some fresh spark plugs. A cold air intake can help as well.
SteelHeadz
Super Moderator
Also Check your Throttle body for carbon build up. make sure the butterfly is clean. sometimes a fuel injector flush helps too.
Utah_jeepster
Super Moderator
Well John there is some you could do to help with your gas mileage,
Air intake and exhaust, an after market air intake and opening up your exhaust will help. The next is chipping it, but at this point your not going to get too much more out of her, 16MPG or so city.
I am afraid most jeeps were not aerodynamically designed.
Your speed-o might be off 3-4% at most due to the fact your jeep came factory stock with 29 inch tires. its a cheap fix if you want to fix that. Most stealerships charge 15 or so for a new speed-o gear and it only takes 5 minutes to crawl under and change it out.
Air intake and exhaust, an after market air intake and opening up your exhaust will help. The next is chipping it, but at this point your not going to get too much more out of her, 16MPG or so city.
I am afraid most jeeps were not aerodynamically designed.
Your speed-o might be off 3-4% at most due to the fact your jeep came factory stock with 29 inch tires. its a cheap fix if you want to fix that. Most stealerships charge 15 or so for a new speed-o gear and it only takes 5 minutes to crawl under and change it out.
wrangleramp88
New member
I have a 4 cyl and it was only a little better .If you live in a hilly area it don't help either (I do).I have a scan tool in mine and I'm up to 14-20 mpg by removing any weight that i didn't need. and putting acetone in my fuel.
strangler4x4
New member
I have a 99 4.0l sport with a 5spd i get between 14-16mpg around town And between 20-25 on a long highway haul at 65mph at 2300rpm with 31 X 10.5's
SteelHeadz
Super Moderator
:bomb:Suck's to be me. after hearing everyone's Fuel ECONOMY, i'm NOT happy to report that i get 8-9 miles to a gallon. LOL. AMC 360, Edelbrock Performer Cam,Lifters,Springs Intake and Carburator. 35x14.5 -15 Pitbulls.Go figure.
Utah_jeepster
Super Moderator
SteelHeadz, you might be in luck, you didn't mention if your re-geared your axles. Once you make the jump to 35 inch tires you need to re-gear the axles to get your transmission working for you again.
For around 560$, a good axle guild, and a long weekend you could regain 4-5 miles per gallon.
SteelHeadz
Super Moderator
Yeah, i've been thinking about that lately. i probably will consider that after Christmas. I still got a lot of presents to get for Christmas and Wedding anniversary 2 days after that.
Wrangl3r93
New member
1993 Wrangler 4.0HO with 263k miles on it averaging 14-16 depending on how my mood changes(40%highway/60%city). Rolling on 33x12.50 tires but I'm geared down to 4.10 with the manual transmission.
