JKOwners Forum banner

Tire size question

2K views 3 replies 4 participants last post by  funfred 
#1 ·
Im sure this shows up a lot, but im doing some research and I would like a little confirmation. I am currently running 255/75R17 tires on XD797 SPY wheels. I'm hoping to do a lift soon and move up to 35" tires. It seems like the size I would be looking at is 315/70/17. Is that the common 35", technically that is 34.4" right?

I have a 2dr with 3.73 gears. I know the 4.10 would be better, but its not in the budget. From what I am reading it wont be ideal, but not too terrible either. I'm planning on 2.5" AEV lift with geometry correction brackets.

What is the spare tire situation with the 35s? Pretty sure at the very least I need a light extension, but is it structurally strong enough to hold a 35 or does the entire bracket need upgraded?
 
#2 ·
315/70/r17 is technically a 34.4 and measures more like a 34 when mounted on a rim. (my duratrac is exactly 34inches on the spare tire)

Mine is also a 2 door but has the the 3:21 gearing but is a manual. its a bit of a slug but not really that bad with my "35s" with that said I am planning to regear next year (tax returns baby! lol) and install some lockers. but its not really needed.
If you have an automatic your vehicle will drive similar to how mine does overall with speed and gearing. You should be fine. If you do A LOT of mountain driving, you might want to make sure your trans temps stay down. I have issues with mountains needing to shift constantly and my engine runs warm too so im sure your transmission will be working a lot more going up big hills. .

As far as tire carriers, there are options out there. I went with a swing mount to a new bumper but you can technically get away with ones that mount to the door. I wouldn't trust them though.
 
#3 ·
Gearing depends on where you are at, what engine and transmission you have, and what you plan to do with it. IF you have a 2007-2011 automatic and live in the mountains it will suck. If you have a 2012-current and live in flat lands near sea level it won't be so bad. Off road with improper gearing means you will be running a bit fast to get over obstacles, this is typically not a good thing as stuff tends to break when you are ramming into things.

If you don't go off road and don't mind shit performance with poor gas mileage then your current gear set up should be fine.

I generally recommend a spare tire delete as you really don't need a spare for everyday running around. Get on board air and a plug kit and save the weight of the spare and the expense of a tire carrier. If you wheel then throw the spare in the cargo area.
 
#4 ·
'14 2dr with 3.73 manual...
No issues running 315/70s.

I opted for TeraFlex's spare carrier and hinge kit. I want the floor space for cargo when offroad.

Lots of people will tell you the OEM spare carrier will handle the weight of oversized tires...I don't doubt it. In my case, I was more concerned about long term effects of bashing and bouncing around offroad at speeds above a crawl and considered the TF kit a one time insurance premium.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top