Poor fuel mileage

[glwood]

I used the app on my iPhone waze to use until my gear came in after install it was right on

Apps and internet charts usually get you close, but don't always take into account the transmission of the 'charted' vehicle. They usually give a more conservative gear ratio that might not work in real life. If yours turned out good, you're lucky.

 

[Snow-proofed4x4]

Went from 31 inch tire to 35 inch tire. Now my fuel mileage dropped 7 mpg. Any help?

I have a 1998 TJ that someone built it started life as a 4cyl but now it’s a 4.0l 6cyl with the ax-15 np231 combo. It’s been regeared to 4:56 and I’m able to get around 14-16 mpg average. I run Mickey Thompson Deegan 38 Pro 2 15x10 -44 wheels and Falken Wildpeak at3w 35x12.50r15s. It’s riding on a 4 inch skyjacker short arm suspension lift with slip yolk eliminator and Adams driveshafts. Dana 30 front 35 rear open diffs no body armor no gear inside not even a back seat and a Fishbone off-road bumper and no spare tire ( Yes it’s a pavement pusher because I have a 1991 yj for the trails and I just use the tj as a freeway driver/ my reliable car that I use to go on long trips) so if you do gear it correctly and keep it light and run all terrains you can still get respectable fuel economy but your not going to have a trail worthy build that’s ready to concor whatever the wilderness has to offer and still get any type of respectable fuel economy that’s just my 2 cents

 

[AndyG]

My jeep gained 6 miles per gallon instantly when I regeared it .

If you are going to run 35 ‘s, that’s going to cost you about $36.00 per tank , and that won’t take long to pay for a regear.

If you don’t set it up right like Rob said , it’s going to ultimately cost you more , plus the pleasure of having it right.

I really enjoy my Jeep far more than I anticipated I would regeared. A Jeep with no power is a drag.

I never see anything on this forum that folks debate so much as regearing.

If I bought a Jeep tomorrow with large tires and stock gearing , it would be driven directly to the shop to be regeared .

 

[Alex01]

This thread was from 2017. I bet he realized by now his mileage will never be the same as with 31s.

 

[tworley]

If you are going to run 35 ‘s, that’s going to cost you about $36.00 per tank , and that won’t take long to pay for a regear.

Your gas is cheap. I consistently hit $45-50

 

[AndyG]

Your gas is cheap. I consistently hit $45-50

I'm just being conservative on the cost per mile at 7 vs 14 mpg , and 15 gallons per tank at 2.59.