Which size tire should I run?

33's and 3.73 gears is not a good combination. The obvious advice would be to regear the Jeep but I realize that is not in the budget or build plans for many people. If your not looking to build it up then I personally wouldn't be nervous about doing some work to it and dropping to 31's. I ran a TJ on 31's all over the mountains of Colorado and had a great time. TJ's can look really good with a set of aggressive 31's. You would need to lower your Jeep as 31's on a 4 inch lift looks silly. Fortunately stock suspension parts are cheap and plentiful and in many cases are better than aftermarket. I've run 32's and they really are not a very good size. 31's and 33's have some advantages. 32's pretty much take away those advantages and leave you somewhere in the middle, not being great at anything. Alternatively, you can stick with 33's. You already know how it drives. If you can accept it and be content with the decreased performance then you have lost nothing.

SouthernTJ2000 said:

Okay, so here's my next question. What gear ratio should I run If I wanted to stick with the 33's? Also, if I went 31's, what should my max lift be? I don't mind spending some coin, as my overall plan for the jeep is to make it very capable off road. I know this is a loaded statement, as "very capable off road" is pretty damn broad when it comes to a jeep...lol. I know for at least the first year or so I'm going to stick with the current axles in it. However do plan to go dana 44 axles down the road.

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Which tranny are you running?

The NV3550 was the only manual available in 2000. I have an 02 with that transmission on 33's & 4.56's. I love the combo. But I've also never driven it on any other ratio so I can't say. Somebody will probably say you need to be on 6.50's. I have driven other TJ's with the 32RH on 33's & lower (numerical) ratios and the performance of the 33/4.56 is night and day difference. Some of that will be the tranny ratios, but a lot of it is the axle ratio.

SouthernTJ2000 said:

Okay, so here's my next question. What gear ratio should I run If I wanted to stick with the 33's? Also, if I went 31's, what should my max lift be? I don't mind spending some coin, as my overall plan for the jeep is to make it very capable off road. I know this is a loaded statement, as "very capable off road" is pretty damn broad when it comes to a jeep...lol. I know for at least the first year or so I'm going to stick with the current axles in it. However do plan to go dana 44 axles down the road.

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This website will let you look at all possibilities.
http://www.grimmjeeper.com/gears.html

If you are going to upgrade and build axles in the next year and are happy with 33's then I would stick with them. No sense in regearing your current axles, unless you have the tools to do it yourself. In the meantime I'd recommend figuring out what your final build goals are. This forum has lots of resources and many folks who are willing to help you spend your money. : ) It will save you a lot of time and cash if you have a plan and don't do things twice. I would also advise to come up with a realistic budget. You can build a Jeep on thousands or tens of thousands of dollars.

SouthernTJ2000 said:

Okay, so here's my next question. What gear ratio should I run If I wanted to stick with the 33's? Also, if I went 31's, what should my max lift be? I don't mind spending some coin, as my overall plan for the jeep is to make it very capable off road. I know this is a loaded statement, as "very capable off road" is pretty damn broad when it comes to a jeep...lol. I know for at least the first year or so I'm going to stick with the current axles in it. However do plan to go dana 44 axles down the road.

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I have 33s with 3.73 gears and I plan on re-gearing to 4.10s given Mines the 3 speed auto so yours will probably be a bit more stout mine struggles with hills doing anything above 40 so if you want to keep the 33s then I would have to say it would probably be best to re-gear! Otherwise 31s would probably be your best bet.

SouthernTJ2000 said:

Yeah. I'm currently reading about the Super Dana 35 upgrade. I believe that may be the way I end up going, as I have no desire to do any rock "wrestling." I also much prefer the slow and steady approach as opposed to the "hold muh beer and drop a gear" approach.

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People love to bag on the 35 but based on what you just described, I wouldn't bother with the expense of upgrading stuff unless you just like to spend money. Is it the most capable rear end Jeep ever used? No. Is it pretty capable for what probably 90% of TJ owners need? Yeah. It is. IMHO.

33's & 5spd with 3.73.. I started there. It sucked. 5th gear was non-existent.
regeared to 4.56's, kept the 33's. If I thought I would ever go to 35's I would have gone with 4.88's.
Pulls hard on the highway. Long uphills are a breeze even in 5th.
Zero complaints. Throw in a B&M short shift and you'll be smiling often.
I put about 50 miles a day.. it's my daily driver.

SouthernTJ2000 said:

Thanks for the info and helping, its greatly appreciated. Its refreshing to see a message forum still around and thriving. I despise having to deal with the majority of the "social media" couch wheelers/wrenchers/experts on FB groups.

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I have no idea how you ended up here but that last sentence (now in green) tells me that you should do fine with your new (to you) Jeep.

Also, IDK if there's a minimum number of needed posts before posting pics but


so I'll add one that shows you what happens when you go way too slow in about 14+ inches of heavy wet snow without a lift.

Even with lockers You get stuck.


Not that you have to worry about that in TX.

JEEPCJTJ said:

I have no idea how you ended up here but that last sentence (now in green) tells me that you should do fine with your new (to you) Jeep.

Also, IDK if there's a minimum number of needed posts before posting pics but


so I'll add one that shows you what happens when you go way too slow in about 14+ inches of heavy wet snow without a lift.

Even with lockers You get stuck.
View attachment 511539

Not that you have to worry about that in TX.

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Sweet ‘5 in the background.

SouthernTJ2000 said:

Man, I just clicked that link....WOW!!! That is great, thanks so much!!!!

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Grimmjeeper is indeed great, I use it nearly every day. One initial hint... at the place where it says "Enter your own numbers" don't let that fool you. Click on it and you'll see a full menu of transmissions which automatically inputs all their ratios for you, find yours and click on it.

After entering axle ratio, tire size, etc. the very last chart is what I find most useful... Road RPMs at given speed in miles per hour. You can tell it what speed you want to see the rpms at and it'll give them to you for all the transmission gears. And on tire size, go a bit smaller diameter than what the sidewall says. Like a 35" is usually closer to 34.4 or 34.5 in reality. Doing that bumps the road rpms up a tad for a slightly more accurate rpm indication.

SouthernTJ2000 said:

This was last Saturday on the way home from picking her up.

View attachment 511560

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Nice clean unmolested TJ!!

SouthernTJ2000 said:

So I'm new to the Jeep world and just picked up a '00 4.0 5 speed. It has a 4" RC lift, stock dana axles (30 & 35), and 3.73 gears. It currently has 33x12.5R15 tires, and I thoroughly enjoy the look. However the tires have seen there better days and I plan to replace them within the next 2-4 months. My question is should I go back with the 33x12.5? Or should I maybe do a 32x11.5 or 31x10.5? I'll probably put 400 miles a month on it. Most of those will be tooling around on pavement around 45ish mph, with some occasional hwy speeds of 65ish. However I do plan to off road as much as I possibly can. Any and all input is greatly appreciated. I did do some searching, however didn't quite find my answer, so figured I'd ask.

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I second or third the 31's being too small. I had 31's on mine and it looked great on a 2.5" lift. Another inch and a half might make it look pretty off.





Also, RC lifts and especially the shocks are garbage. I have their 2.5" shocks right now from a PO and they just suck. I have to drop my gas tank again to get to them so that's a future upgrade. So if you shorten or go stock, keep that in mind. It'll drive four thousand times better than it does now.

As for gearing, currently at 65 you'll be at 1900 RPM. Respectively, with 32's and 31's your RPM at 65 will be 1986 RPM and 2000 RPM. Your gears a little tall for 33's currently going 65 on the freeway. One good hill and you'll bog down. My 2.4 can't do a hill on 30's and 4.10's, but that engine has almost half the displacement. Most of the time, on Route 2 into Cleveland, I'm at about 2500 RPM with a 0.75 5th gear, 4.10's and 29' tires. On my 31's I think I was at like maybe 2250. Very hard to keep up. 33's wouldn't get me off of the on ramp.

At 4.56 gears, at 65 MPH and 33's (I put in 32.5 to dial it in more precisely), you'd be at about 2400 RPM which would help keep you moving on an incline. A lot of guys on here run at 75 MPH at 3k and have for years and have no oil burning issues, so I would personally agree with 4.56 gears for 33's, a 5 spd, and a 4.0. Seeing your Jeep's photos, I'd adapt your gears to the tires. Your Jeep looks real good currently on 33's.