Bigger tires and Torquiness

[Farmer Dean]

I've got a 95XJ with 3.5" lift, 3.55 and 10.5x31's. I too get between 19 @ 20 mpg. I keep it right at 65 mph (2000RPM). I regeared my speedo when I changed tires and have also checked speed with GPS. Speed is within 1/2 mph. 100K on motor and it runs well. That's conservative trip driving, no passing gear, rabbit starts, etc. FD.

 

[JohnX]

I've got a 95XJ with 3.5" lift, 3.55 and 10.5x31's. I too get between 19 @ 20 mpg. I keep it right at 65 mph (2000RPM). I regeared my speedo when I changed tires and have also checked speed with GPS. Speed is within 1/2 mph. 100K on motor and it runs well. That's conservative trip driving, no passing gear, rabbit starts, etc. FD.

Any mods that would increase mileage? Filter, chip, exhaust, etc.?

I drive very conservatively, and it seems that our Jeeps are very similar...what could make that big of difference?

 

[JohnX]

ok so do yall know of a web site that tells what the sizes such as 285/75/15 really mean??? cause im tryin to find a 31.5" tire. thanks

I like this one...

http://www.miata.net/garage/tirecalc.html

It is a Miata page, but very useful none the less.

 

[Beachmonkey6]

Sweet thanks that answerd my question bout the tire sizing.

 

[learjets]

I think you better check your math...I have that EXACT combo (94 XJ with 31/10.5 BFG AT Auto trans with 3.55 gears and 3 inch lift) and mine only gets about 17-18 mpg IF I keep it under 65mph. Try checking your speedo with GPS and see if it is right.

John X
Yep I've checked my speed-o and recallibrated it with new speed-o gear with a 32 tooth gear after changine the tire to BFG 31's see
http://go.jeep-xj.info/HowtoSpeedoGears.htm and checked with my GPS.

94 XJ has 230000+ miles but the engine is a new DC long block with about 110000 miles on it now. Mostly stock except aftermarket (K&N cone filter) and induction system, Cat converter has about 50,000 miles on it and a "turbo" muffler.
For work I drive from Indy north it Michigan and south to most of Kentucky, so my highway miles is all at 65-75 miles a hour, A/C on, and no traffic jams.
I've been running the tire pressure at 36psi.

PVK

 

[Jeeper]

hey, I'm getting ready to put a 3.5" RE super ride lift on my 88 xj. I believe that I'm going to go with 31" Trxus A/T tires. I've heard alot of talk about regearing to compensate for the larger tires. I'm not sure what gearing I have now, but I do know that I have a danna 35. I want my xj to have plenty of torque and still have normal exceleration. do you think that 4.11s or 4.56s will do? or will I even have to regear at all? I'm also looking around for a danna 44. thanks.

Johan

 

[JohnX]

94 XJ has 230000+ miles but the engine is a new DC long block with about 110000 miles on it now. Mostly stock except aftermarket (K&N cone filter) and induction system, Cat converter has about 50,000 miles on it and a "turbo" muffler.
For work I drive from Indy north it Michigan and south to most of Kentucky, so my highway miles is all at 65-75 miles a hour, A/C on, and no traffic jams.
I've been running the tire pressure at 36psi.

PVK

Now it makes sense...new motor and a few upgrades.

Some day (when I finish all this suspension crap) I'll have to upgrade the motor a little bit.

 

[Beachmonkey6]

The 4.11s should work perfectly for 31's from what ive heard.

 

[Jeeper]

The 4.11s should work perfectly for 31's from what ive heard.

so I think that I might get around to that whenever I get my danna 44. I'll just drive it with all the stock stuff until then. I'm just going to leave it at that but if anybody thinks that this is a bad idea then tell me why. maybe it will save me some trouble.

thanks again

 

[cal]

so I think that I might get around to that whenever I get my danna 44. I'll just drive it with all the stock stuff until then. I'm just going to leave it at that but if anybody thinks that this is a bad idea then tell me why. maybe it will save me some trouble.

thanks again

No, if you plan on buying a 44, leave it as it is until you get it. 31's arent that hard on stock gears, you'll just notice less power.
If you are on a dana35, be light on the throttle when you get offroad, those axle shafts snap pretty easy.. not a SUPER danger, but be prepared for the possibility of it.

 

[Jeeper]

No, if you plan on buying a 44, leave it as it is until you get it. 31's arent that hard on stock gears, you'll just notice less power.
If you are on a dana35, be light on the throttle when you get offroad, those axle shafts snap pretty easy.. not a SUPER danger, but be prepared for the possibility of it.

gotcha. so I'll try to get my axle before I lift it, but if I dont then I'll just take it easy until I do. then I'll re-gear when I have my 44.

thanks for all the advice