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Opinions Wanted On Tire Sizes

FishyXJ

NAXJA Forum User
Location
Beaverton
Wanted to hear what people have to say about this-

My tires are almost done and I will be purchasing new ones this month. My question is should I run 33's or 35's?? I have a 99 with 4.5 rubicon express lift and front spacers. I currently run 33 Xterains. I can actually get a better deal on some new 35 KM2s but wanted some opinions first. Any help would be great and pictures would be awsome. My XJ is my daily driver and does have stock axles. I do like to wheel but get to very little. Will 35's be ok? Let me know what you guys think. Thanks.
 
As a general rule I would agree that 35's do require some upgrades over 33's. However, in this case I am not so sure they are as significant until we understand the rest of the Jeep.

D30 low pinion? gears? lockers?
8.25 Rear or D35 (was that an option on the ABS versions?)? gears? lockers?
What rear suspension?
Stock steering?
what track bar?
aluminum or steel wheels?

Here is what I am getting at. If you are open/open with appropriate gears (4.10's minimum) and have a D30/8.25 and are mostly driving on the street I think the 35's would be fine. I would prefer they are also aluminum (lighter) wheels, and a upgraded steering set up, but I have seen much less work fine on the street.

On the other hand, if you have less than 4.10 gears then forget it, heavy wheels, stock steering, lockers, D35 instead of 8.25 all make it worse.

You might also check the weight of the Xterrains in comparison to the KM2's. I believe the Xterrains are pretty heavy and so the larger tire size isn't quite as bad as going from say a 33" At.

Give us the rest of the details and we can continue to fight it all out with the right info ;)

Michael
 
Thanks for all the help so far and here are some of those key details I left out.

-8.25 rear/Dana 30 Front No gears or Lockers
-I have the RE 4.5 Super Flex w/ rear springs lift. So 3.5 Springs plus shackles I believe for the rear suspension.
- Stock Steering that I hope to upgrade soon but RE Track Bar that came with lift kit.
- Steel Black Rock Crawler Wheels

It looks like the pro comps weight is about 53lbs, and the BFG in a 35 is about 61lbs.

Are the Higher gears key? I dont want/need lockers, but while my jeep is not a race car, we do live in oregon {where people drive slower the hell} and I dont mind my current cruising speed or gear ratio.
 
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Are the Higher gears key? I dont want/need lockers, but while my jeep is not a race car, we do live in oregon {where people drive slower the hell} and I dont mind my current cruising speed or gear ratio.

In my mind, yes.
I wouldn't recommend going any bigger without at a minimum 4.10's or 4.56's (your just putting way too much strain on all of the running gear, brakes, tranny, etc). Having said this, I wouldn't recommend 33's either for an extended period of time.
Stock steering is the second limiting factor.

Outside of those two issues I don't see why you couldn't consider them. It's only my opinion, there will be plenty of others with other opinions ;)

Michael
 
Are the Higher gears key?

NO.

You want lower gears(numerically higher).

After driving a rig with 35's and 4.56's for the last week and a half, I would do AT LEAST 4.56's with 35's. The rig felt slow, underpowered, but it does weigh in at 5000lbs.

IF you are just going to stick with 3.55's, look at driving around on the freeway in 3rd gear, and add a tranny cooler. The 4.0 likes to be at 2500 rpm or above for optimal power and fuel economy. Dont be afraid to rev the engine a bit, I pulled better MPG's with 31's and 4.56's than I did with 31's and 3.07's. Less lag on the engine is always better.
 
After driving a rig with 35's and 4.56's for the last week and a half, I would do AT LEAST 4.56's with 35's. The rig felt slow, underpowered, but it does weigh in at 5000lbs.

IF you are just going to stick with 3.55's, look at driving around on the freeway in 3rd gear, and add a tranny cooler. The 4.0 likes to be at 2500 rpm or above for optimal power and fuel economy. Dont be afraid to rev the engine a bit, I pulled better MPG's with 31's and 4.56's than I did with 31's and 3.07's. Less lag on the engine is always better.

What he said, my jeep is the tank he was driving. It is a pig and has alot of armor. I have aluminum BL wheels on 35 inch KM2's with 4.56 gears, I used to run 33's and honestly that was probably optimal. 33's are plenty for the PNW, and with good tires and 1 locker you can follow us just about anywhere if you armor up a little bit.

-Alex
 
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