Hi all.
I recently bought 4 285/70-17 Duratrac tires for my '10 Jeep. I didn't change the spare tire size. I think there is about a 1" difference in tire diameter. With all the electronic brake,stability, and traction controls on the new Jeeps will I have problems if I need to put the spare tire on? This has never been an issue on any other vehicle I own but they didn't have all these controls.
Thanks for any help.
Dan

 

With all the electronic crap in the JK, a tire size difference may be seen as slippage by the anti-spin system. I don't know whether it may go into limp mode, but why take the chance.

 

If your only using it as a "spare", then I don't see why it would be an issue. A lot of people don't have a same size spare. As the post above stated, the jeeps tend to be picky at times and randomly at that!

 

That's what I was afraid of. Limp mode is never a good thing. I don't think 1" is all that much but I don't want to screw something up. I got 4 aftermarket wheels and the Duratracs. I put the factory set in storage. I didn't want to pull a brand new tire off the factory spare rim if I didn't have to. The rims weren't cheap and I use a spare tire cover so...no new spare rim.

 

If I have a flat I will need to put the spare on. At that point I don't want to add insult to injury by limping home. Yes, the Jeep system can be picky (and overly sensitive). I have an uneven intersection I cross over every day. Sometimes the traction control triggers because apparently I can't cross the road all on my own.

 

If you have to replace a front tire, it may affect the ESP pretty badly. The steering got knocked out of whack on one wheeling trip I went on in my '07, and I had to stop and do a roadside steering adjustment. Whenever I went around a corner the brakes would start pulsing to slow me down because of the ESP. It was very annoying and pretty dangerous. Once I got it adjusted right, everything was fine. I don't know if a 1" difference in tire size would cause that on the back, I think mainly on the front.

 

You could put it on and take a short drive to see what the Jeep thinks of it. Do not use four wheel drive with the tire difference though. Probably best to test it when you are not depending on it.

 

You have to think about the situations that you would need a spare. I don't live 5 minutes away from any wheeling spots. Most places you have to drive about an hour or more just to get to the trailhead. I can't afford a tow rig and trailer, so my Jeep has to get me there and back. Most tire stores close at 6pm and aren't open on Sundays. So will that small spare take you all the way home and to work on Monday? Maybe, maybe not. I wouldn't risk it.

 

I had a 35" go flat due to a cracked rim not too long ago. It was in the front so it would turn hard during braking and the TPS sensor was going off, but that was it. Was doing about up to 50MPH for a few miles and nothing went weird. I'm sure the flat was more than a 1" difference. I had no issues personally. Hope this helps.

 

It all helps. I think I'll look for a cheap 285/70-17 or other 33" tire for a spare. I'm not willing to pay Duratrac money for something that may rarely touch the ground. Maybe a recap even. Although I hear the same size tire will vary some from brand to brand. Hopefully not an inch.