Greetings fellow jeep lovers, my question is related with ensuring I use the most practical tire size for my jeep based on my lift of 3".
Knowing that tire size is of course tied to gear ratio (my front is 3.55 Dana) I believe my tires should probably max out at about 29 or so inches. I want to ensure my speedometer is correctly reflecting my speed and that my highway is not negatively impacting my transmission so that I can still drive at 60 or 70 mph. What I am most curious about is how do I correlate tire size such as my friends 245, 75, 16 tires to either a 29, 30, etc. tire size? I do know that the 16 is rim size and believe the 245 is the width of the tires, and also believe that the 75 ties to height from rim to thread.

* So, does one specific number of those three number tie back to a 29 or 30 inch tire?
* I like slightly wider tires, how wide can I go without concern and having to buy hub extenders?
Thanks in advance for clarification :icon_ wink:

 

A lil toy you can use https://tiresize.com/calculator/ And if you want gearing vs tire size http://www.morris4x4center.com/jeep-...atio-chart.htm

 

That's the same one I use Andrew for tire size.


For the proper speed to show you just need to change the speedometer gear i8s all for the gear/tire size to show. Also consider buying some steel wheels for your new tires so you don't have to use spacers (not good) and a good set will cost almost as much a set of cheaper steel wheels.


With the stock gears you can push it and run a 31" tire with your 3" lift and looks good with that height to boot. Cheap steel wheels can be bought from Summit, Jegs, most all off road jeep online dealers.

 

3" of lift and 31s on stock 3.55 gears is a very common and versatile setup. 29" tires are just about stock, it would look funny like that.

Keep your factory 15" wheels and run 31"x10.5" tires. I don't really know what that works out to in metric but there's plenty of calculators online.

 

Thanks Andrew, those links are both informative and coo!

 

Thanks XJ I thought 29's may be close to stock, I was thinking 31's, my buddy has 31.5's and they make the truck look beefy but not overdone.

 

And if you want to see lift vs tire sizes http://www.myjeepxj.com/cherokee-lift-kits

 

Why would anyone use stock wheels and spacers on a narrow stock wheel for a 31x10.5" width anyway, when quality spacers cost about the same as a full set of steel wheels and you get the proper size.


Are you running the 35" tires with the stock 3.55 gears still?

 

Im not advocating spacers, just saying the stock wheels will work just fine. OP could definitely get steelies for the wider look.

And yes, I am. And it still sucks.

 

Hey buddy do you have many hills on the highways in your area? If so do you have any issues with trans, cooling with it the gears, I can tell the difference when I switch from my 33's to the 35's I run mostly all off road with them.

 

Yes it's very hilly around here. I drive over a small mountain on my way to work every day. It's speed limit 50 but by the top I'm usually only doing about 40-45 in 2nd gear. The trans temps only climb when the torque converter isn't locked. The jeep would much rather be in 2nd at 3k+ rpm than in 3rd with the torque converter unlocked.

The other day it was 90+ degrees while sitting in stop and go traffic and my trans temp gauge was higher than I'd ever seen it, but not high enough for concern.

I try to be good to the jeep. I realize I'm asking a lot of it pushing those big tires all the time and I don't like doing it but regearing just isn't in the cards at the moment.

 

Hopefully these can help you guys.

 

And this

 

This

 

And finaly this. Sorry it wasnt letting do multiple pics in one post.