Going with 31's??

Chris06TJ

Active Member
Joined
Dec 4, 2012
I have a Jeep TJ that i just put a new set of 31x10.5x15 BFG's AllTerrain's. Its a 4.0 automatic transmission. Why all of a sudden does my gas milage suck to crap? it was great before but its just horrible now, I dont consider 31's to be too extreme especially since I only went up from a 30x 9.5. Any thoughts?
 
Wider tire = more rolling resistance. Deep aggressive tread= more rolling resistance. Larger diameter changes total gear ratio could change optimum engine rpm to ground speed
 
I thought about that... the day i bought my tires i measured my mileage to work, the day after new tires i measured again, over 18 miles i lost 6/10 of a mile.
 
I record my fuel milage religiously, and find its plus/minus at least 1mpg over many years OD recording. How many tanks of gas have you run thru to determine its "horrible".
 
6 months worth im getting about 225miles off a full tank, even experimented using 93 octane, complete tune up etc.
 
your miladge is spot on with mine before I went 3.73 gears in my axle. At 225,I started looking for a gas station.I keep an eye on it religiously since my guage sometimes doesn't register.Since going to 3.73 from 3.08, I go 10 to 15 miles farther on a tank. I got a sweet spot at 60mph with cruise control that nets me about a mile and quarter better in gas.Above or below that,around town,nets me the same as the old days. Yea,I did change the gear in the transfer case.
2001 wrangler,6.0,auto, 31/10.50s is what I have.
 
hot damn...I grew extra cylinders....just hate they were Ferd!!!!

ok,2001 wrangler sport...4.0,auto,3.73,31/10.5s


Better?????
 
Back
Top