unidentifiedbomb

I recently put a buddy's 33" spare on my 4" XJ and really liked it so now I'm already bookmarking wheels and tires for when I want new ones. I know I want to get the 33/10.50 KM2s but if I can I would rather not regear. Just wondering how it is? When I eventually switch over it'll most likely be in flat DE, Rausch OHV, Ocean City Jeepfest and such, nothing too hilly. I love the highway mileage I get on my 31s but the gearing/tire chart doesn't take into consideration of widths so I think it's not specific enough to give me an accurate expectation. The 33" KM2s are only 5lbs heavier than my 31" duratracs and the same width so height is the only factor, how much does that account for? Sorry for the rant/questions I'm just researching with little threads on the topic.

MoparNJeep

Your still losing torque from the 33" diameter but I imagine the less weight would help some. The less rolling resistance should help most with better mpg. My metric 35s km2 where only 6lbs heavier than my metric (33.1)x(11.5)x15s km2 and I didn't notice any loss at all in get up and go.

cleenrob

3.55s and 33's suck, if your going to run 33s i would highly recommend regearing

thatXJguy

My 33x12.50s are 49 pounds each. That's almost 200 pounds in tire alone, and doesn't count my steel wheels.

The 10.50s are about 1/6 lighter. So you can shave off about 30-40 pounds. In all, that might help with your giddy-up a little. But if you have a lot of off-road equipment in your Jeep already, it's not going to make a heck of a difference.

I run 3.55 gears with my 33s and I would like to gear to 4.56s. You might be able to get away with 4.10s with 10.50 wide, but I would STILL go 4.56s. The diameter of the tire is what causes your engine to work harder to still push a single tire rotation, not really the weight.

Fred/N0AZZ

If I were going to a 33" tire I would go with the 12:50's over the 10:50's for sure, your losing quite a bit of traction there with no real loss in mpg over the 10:50 tire.

When I re-geared from 3.55 to 4.56's I gained about 5 mpg (mpg was checked using a GPS) and also gone was the constant up/down shifting of the AW4 on almost level ground. Off road performance was enhanced also with the gear change.

The gear change and addition of front/rear lockers at the same time had to be the single best upgrade I have made to my Jeep at one time.

timamybrown

When I ran 33x10.50 with 3.55s it wasn't to bad it would down shift from time to time going up hill or driving into the wind. I think you would be happier if you did re-gear. For driving on road and mild wheeling I liked my 10.50s better than my 12.50s. The 10.50s had better on road manners and seemed to find traction faster of road for me anyway.

unidentifiedbomb

I'll most likely keep the stock gearing at first then regear to 4.11, but I've read many prefer the 10.50 as I love that width too.

thatXJguy

I love the 12.50s a lot more than the 10.50s.

cleenrob

i run 4.10s with 33x12.50's on steelies, its ok but its still pretty sluggish on the high way, if your going to regear i would highly recommend 4.56's you wont regret it

*i got my axles basically free other wise i would have regeared to 4.56*

Fred/N0AZZ

Don't think your going to be very happy with the 4.10's, I have the 4.56's and really wish I had gone with the 4.88's instead.

The 4.56 gear with a 33" tire works out to a stock tire/gear size. The 4.10 will not net you as good of mpg as the 4.56 either. But was just a suggestion from what I had found and YMMV.

Good luck with your new tires.

caronaxtr

I ran stock gearing with 33-10.5/15's and it was ok for a weekend wheelin rig, but daily driving was pretty bad. I regeared to 4.56 and ran the 33's and that was great. Now I'm on 35's and really wished I went 4.88

I wasn't a fan of my 10.5 width tires, but to each their own. If you're gonna regear, don't waste your money on 4.10, go 4.56. Just my $.02

McCaffrey

That's what I run. Seems totally fine.

Tom95YJ

X2. I run 33's and 3:55's I hate it

unidentifiedbomb

The reason why I thought 4.11, is that wouldn't that be about the same as 3.55 with 31s? I'm getting around 20 mpg on the highway which is most of my yearly driving (5,000/yr) from school. But I suppose 4.56 will be the best of both in town/highway/and wheeling. Thanks for that.

XJEvo

I ran 3.55 on 31s in my old 99 AW4 and now 3.07 on 31s in my 98 AX-15. Both are horrible on any sort of highway driving. Merging into traffic, inclines greater than 5*, etc. All are pretty bad. I can only imagine how much worse it would be with 33s, a high mileage 4.0, and a bit of armor. I plan on swapping in 3.55s into my 98 as soon as I find a decent set of axles.