Bigger tires and Torquiness

[Beachmonkey6]

Ive got a '90 xj and im soon so install a 4.5'' lift with i think ill get 32's. When upsizing tires to 32's am i going to feel much of a differnce from stock tires? if so then how much? and would it be much different from 31's? How can i fix this problem?
thanks!

 

[xjj33p3r]

You will feel a difference, but it also depends on what material your wheels are made out of. You can correct this by changing your gearing to 4.10 or 4.11's.

 

[Yucca-Man]

You will feel a difference, but it also depends on what material your wheels are made out of. You can correct this by changing your gearing to 4.56's.

Fixed it for ya.

 

[TheNerd]

Yucca has the right idea.

 

[cal]

Ive got a '90 xj and im soon so install a 4.5'' lift with i think ill get 32's. When upsizing tires to 32's am i going to feel much of a differnce from stock tires? if so then how much? and would it be much different from 31's? How can i fix this problem?
thanks!

I did 4.5" and 32's. I am now running 4.56 gears and am very happy with it. A friend local is on 4" and 32's with 4.11 gears and struggles to keep speed uphill. He lost about 5mpg (he's getting 12's now) and i'm sitting at about 17 mpg. Go 4.56 gears. Your going to find you want 33's later (spare 32's come to be hard to find) and 4.11's wont cut it then.

 

[JohnX]

4.56's all the way

I started with 32's also on 4.5" lift. The 4.56's are perfect for that combo, good mileage and good acceleration.

 

[Beachmonkey6]

ok i have 3.55 gears right now on a dana35. And will get the RockCrawler 51 series wheels. How much would it cost for me to get 4.56 gears and all the parts i need? I dont have a very high budget so i need to make this as cheap as possible.

 

[Yucca-Man]

ok i have 3.55 gears right now on a dana35. And will get the RockCrawler 51 series wheels. How much would it cost for me to get 4.56 gears and all the parts i need? I dont have a very high budget so i need to make this as cheap as possible.

Let's see...that list would include:

• Stronger rear axle (29-spline C8.25", XJ D44, or Explorer 8.8" )
• 4.56 gears for said axle
• Locker would be a good upgrade; since you have to regear anyway this is a good time to save some labor and add that assembly
• New (longer) rear e-brake cables

I'd advise waiting on this until you can actually afford to do it.

 

[Lawn Cher']

Let's see...that list would include:

• Stronger rear axle (29-spline C8.25", XJ D44, or Explorer 8.8" )
• 4.56 gears for said axle
• Locker would be a good upgrade; since you have to regear anyway this is a good time to save some labor and add that assembly
• New (longer) rear e-brake cables

I'd advise waiting on this until you can actually afford to do it.

Don't forget matching gears for the front axle.

 

[Beachmonkey6]

Alright well if i dont have the money to buy a new axel and stuff then should i just get a 3- 3.5'' lift and have 31's or 32's?

Or if there is a such thing as 31.5's i should get those, but is there?

 

[Lawn Cher']

You'll just wanna go bigger later. Get the original lift you wanted, and run 31" tires until you can afford to regear, or just run the bigger tires and live with the reduced power and fuel economy for the time being.

 

[cal]

Alright well if i dont have the money to buy a new axel and stuff then should i just get a 3- 3.5'' lift and have 31's or 32's?

Or if there is a such thing as 31.5's i should get those, but is there?

Buy the 4.5" lift, get 31's or 32's for now, and dont get on the gas real hard, especially in the rocks. When you have a couple hundred dollars saved up, hit a junk yard and get an 8.25 rear end off a newer XJ without ABS (96+ i think) that has 29 splines - people here can help you find that. It wont cost you more than 150-200, and will bolt right in where your dana 35 is.. You may need to have your driveshaft shortened, but that is $40 and takes a couple minutes at a driveline shop.

The dana35 doesnt hold up well to abuse, i wouldnt waste money regearing it. I drove on a dana35 with 32" tires for about 7 months before I bought something stronger, it will be ok, just dont get on it hard.

--C

 

[JohnX]

I ran 4.5" of lift on 30x9.50's for a while.....way better than stock...no they don't look "funny", and think of all the money you'll save on gas and tires....money you can spend later on gears and BIG tires.

 

[Beachmonkey6]

ok thanks. Is there a size of BFG AT tire that is about a 31.5"er??

 

[Yucca-Man]

Yeah...the 32s.

 

[learjets]

I've got 94 XJ with 31/10.5 BFG AT Auto trans with 3.55 gears and 3 inch lift, works decent for the amount of $$ spent. Any bigger tire or lower gear and would not work well.
I get 19 to 19.5 MPG on the Highway going 70+ MPH.

 

[JohnX]

I've got 94 XJ with 31/10.5 BFG AT Auto trans with 3.55 gears and 3 inch lift, works decent for the amount of $$ spent. Any bigger tire or lower gear and would not work well.
I get 19 to 19.5 MPG on the Highway going 70+ MPH.

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.

 

[cal]

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.

Perhaps his XJ run a little better than yours? A friend and i run -identicle- setups, I get 17, he gets 13. I have another friend with 3.55's and 30's that gets 24 on a manual. It has as much to do with condition of engine, sensors, how hard you accelerate and traffic as it does with gearing and tire size.

 

[Beachmonkey6]

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

 

[JohnX]

Perhaps his XJ run a little better than yours? A friend and i run -identicle- setups, I get 17, he gets 13. I have another friend with 3.55's and 30's that gets 24 on a manual. It has as much to do with condition of engine, sensors, how hard you accelerate and traffic as it does with gearing and tire size.

Perhaps, But I'm a mechanic and mine runs perfect...so how much "better" could it be? Yes, I suppose he could have better exhaust, header, intake, K&N, etc.?

I also have a 97 that only got 21mpg from day one...It dropped instantly to 16 mpg when I put 32's on it with stock gears.

Don't misunderstand me...I am not calling him a liar...but I would like him to verify his numbers to see if there's something i'm missing.