Ideal tire size

[GaryMB]

What is the ideal tire size for a CJ7 that will see some hard offroading, more so trail riding than rock crawling, and regular street driving (at least some freeway)? I'm thinking either 33x12.5 or 35x12.5 bfg muds...not sure on rim size, or if a 35" tire would fit on a 15x8" wheel. Also I'm wondering about contact area vs contact pressure, highway driving, vehicle height, and being able to flex. Any suggestions? I'll be doing a sua, either 3.5" or 4.5", and can do a tj fender flare conversion. Axle strength won't be an issue as they will be dana 44's, disc brakes all around.

 

[jps4jeep]

IMHO, the terrain, gears and lockers would dictate which would be better. Not sure what part of the country you live in, but I am gonna use the north east as my example, cause we don't really have "rock crawling" like in Moab, we have trails. with D44's and 35"tires with 4.88 gear and a locker would be very well suited for the terrain, my only worry would be uing the original 30 spline axles. don't think they are going to blow up the first time you go out, but... after some hard use and abuse, they will start to show wear and tear. if you run this set up (original 30 spline axles, 35" tires and 4.88 gears) but NO LOCKER you will get a lot more life and use out of the D44's especially the rear.

another two options.. you could lock just the front, or upgrade to a 33 spline axle and carrier.

For a bit more durability, 33's 4.56 gears and front and rear lockers on 30 spline shafts would be a very good set up, (almost bullet proof if wheeled propperly) if you opted for the 33 spline units, You will definatly have trouble trying to break this set up.

 

[GaryMB]

I'm near the San Francisco Bay Area in California, about 1-2hrs from several offroading sites, including the Rubicon. I've pretty much only gone to Hollister Hills, where the Top Truck Challenge is held, and do alot of trail riding and some (not much) rock crawling...steep, rutted, uneven, flex-demanding, sometimes muddy, rocky trail rides. Since I will be moving closer to the rubicon as well as some mostly non-rockcrawling areas soon, I'd like to keep my options open as far as terrain goes. I do plan to be locked, hopefully front and rear selectable lockers, but at the very least I'll throw a selectable locker in the rear. Also I'd like to keep decent or at least manageable highway driving characteristics. So basically, I'm looking for the perfect the tire size, and am wondering if I can interchange rims between 33's and 35's should I ever decide to switch between the two. Oh, and jps4jeep, you are concerned that a locked d44 with 35's would be a little more prone to breakage than is desireable? How would a stroked 4.0L affect this situation?

 

[yjdave]

New wheels

You will be fine w/35s and d44s 30spl......repeat.....repeat...Pick you gears to match your drivetrain..4.88s will suck if your running a 3pd auto and 33s or 35s....Check your gear ratios in your transmission and t/c, pick a size tire, then decide on f/r r/p.Oh, be the way, rubicon loves to beat the #%&* out of BFGs. Pick a better tire...also 15x8 will be fine w/12.50s you want a little more bulge when playing in the rocks.....PS let me know when you hit the con, its been a year and i'm itching to get back.

 

[Sully]

RE: Re: New wheels

Agreed, the 44's will be plenty strong for the 35's. 4.88's would be killer for that auto. Especially with 35's. It may be slow on the highway but it will crawl great. I know a guy with 4.88 and 33's and a 3spd auto. He can only do 65 but hey who cares when you got gears like that. Isnt this jeep going to be set more towards off road use? I also agree on the bfg mt's. They are good tires but IMO they are not the best to run for your terrain. The MTR works great on rocks because they are soft. Plus you can't beat those sidewalls!

 

[Junkpile]

Sully, I would argue that the rather manly sidewalls of a TSL/SX would, at the very least, stand up as well as those of the MT/R. You would have much better traction on all surfaces except like pavement and slickrock where "grip" is achieved in a different manner. It's a toss-up in your neck of the woods, but I'll vote for some type of Swamper every time.


For an "ideal" SWB tire size with a SUA that is setup for heavy offroad use.....35s-36s, in my opinion. I'd stuff a set of 36x12.50 TSLs mounted on some lightweight aluminum 10" wide wheels under it myself.

 

[felix_santi]

RE: Paragon soon. I need it bad.

The ideal tire size is always the one on the other guy's Jeep.

 

[GaryMB]

Re: RE: A little radiator help.

Sounds like 35's would have their benefits offroad...but would the Jeep still be able to stuff the tires with only a 4.5" lift and TJ flares? A swamper would be nice, but the CJ will be seeing too many street miles for anything more aggressive than a mud tire. So bfg's and rocks don't mix? I'm really a fan of muddy, rutted trail rides, mostly because that's all there is at Hollister, but will be trying out rock crawling more. I did originally buy the Jeep for offroad use, but have since found driving it around, well, anywhere, too much fun for offroad use only...that and I can't justify pouring this much money into a purely offroad toy. The transmission is a 5spd manual, 4.01:1 first gear, the T-case is a Dana 300 with 2.6 low range. It's good to hear that a 35x12.5 would be fine on a 15x8. It's gonna be a while before the CJ is back on four wheels and ready to hit trails again.

 

[jps4jeep]

I never said that a d44 locked with 30 spline axles and 35 tires would not work, heck it is what I am gonna run, I was merely trying to say that it would be in his best interest to upgrade to the 33spline axle to make that particular setup better. if he is gonna replace the carrier, get a 33 spline unit and then add a set of sweet axles in the rear. He mentioned that this is also gonna a street driver too, so that rear end is gonna see quite a bit of use. I would try to make it as bomb proof as possible.

 

[yjdave]

With your set-up i think 4.56 gears would be just about perfect. You might suffer a little mpg(maybe 13 instead of 14) and still offer the get-up and go with the 35s. I agree with swampers(my tire of choice) I have mtrs and they are great on the rocks(at rubicon) but they SUCK IN THE MUD...Just get a radial tire and it will wear and ride good on the street.

 

[Sully]

IMO If your going for 35's you should get 4.88. I got 4.88 and 33's for cryin' out loud. Just imagine how sweet it will be with 35's! BTW if you are worried about 35's and just a 4.5 inch lift with TJ flares. Do a body lift.