Nperryman

So I have a 98 xj and im looking to lift it. I will rarely have it offroad, just the ocassional mild trail. I know the jeep is a gas hog but I also dont want to overdue my build and get 12 mpg. I am looking at doing either a 3" or 4.5" lift and either 30's or 31's (which will have an all terrain pattern). I currently have an 8.25" rear axle and a 29 spline I believe. What advice do you guys have on what size lift and tires to go with so my gas mileage isnt sunk? I know lots of you have had many setups.

blue_on_blackXJ

Your axle is 29 spline. 30's on 4.5 inches will be really funny looking,I had 31's on 4.5 for a while and it was still a little odd. For mileage, stick with 30, though the change from 30 to 31 will be marginal. And keep height tks 3-3.5 inches to keep it proportional, as well as keep vibes down since it seems second gens seem to get them more.

Nperryman

Im thinking about going with a 4.5" zone lift that I can get from a dealer for pretty cheap. It has alot more than the three inch lift, including control arms and tcase drop.

jmm0122

At 4.5" you may need a sye, sometimes a t-case drop doesn't cut it. And don't forget about extended brakelines and adjustable trackbar. 31's might not look to bad and they will help with gas mileage. 30's will look pretty silly with 4.5" of lift though. Kinda like mine did before I got bigger tires.

wiggles

I don't mean to thread jack but I am also looking into a 4.5 inch lift and I am wondering if a drop pitman arm is something I should get

IZAREBL

not trying to thread jack either^... but can anyone give me a rough estimate on how many mpg a 3'' rc kit and 32'' mud tires would get?

Nperryman

What do you mean by help the gas mileage? Like making it less wind resistant?

wiggles

Probably wind and gear wise being that the engine will drive quite a bit different with much larger tires

Nperryman

The 31's will help gas mileage compared to stock?

jmm0122

No you won't need a drop pitman arm.
It all depends on how you drive. I would say maybe 2-3mpg difference, if you keep your foot off the gas.
No meaning you will get better gas mileage with 31's than you will get with 33's, which is what most people run with 4.5" of lift.

wiggles

^ so would I need to change anything steering wise?

Nperryman

What would you estimate me losing mpg wise from stock suspension and 235/75/15? Some say not noticeable and others say like5 mpg ...

no rdplz

wiggles - 4.5 you don't HAVE to do anything to the steering, although a ZJ pitman arm (1" drop) and an adjustable trac bar help.

Nperryman - if you only do mild trails, do a 2" BB (spacers and shackles) lift and 30" A/T's. You'll barely affect your MPG's and you'll avoid drive line vibrations. If you do get any, a simply .75" t-case drop will fix them. If you're set on a 3" lift, avoid AAL (add a leaf) set ups as they tend to sag quickly. Do a full spring pack. 30's won't look too bad on a 3". You'll barely notice the difference if you run 235's - maybe a 1/4 gallon difference. Big rule in building your rig, only do what you need to do. Anything beyond that is wasted money.

When it comes to lifts and tires, the smaller each is, the less MPG's you'll lose. A 2" BB lift and 30's will get better mpg's than a 3" on 31's when driven the same due to wind resistance and friction. I've got 3.5" and 31's and I get about 15 city and 20 hwy if I drive well. Worst I've ever gotten is 13 city and 18 hwy, and that with it fully loaded for camping, including a roof rack full of stuff.

wiggles

Thanks no rdplz

Nperryman

Okay one more, would I see much difference in mpg between a 4.5" and 31's compared to a 3" and 31's?