Different Size Tires Same Axle
Thread Starter
Senior Member
Joined: Jun 2013
Posts: 287
Likes: 159
Different Size Tires Same Axle
I know this has been asked a few times, but for my situation:
My front tires are near new. On the rear, I had some very uneven wear on one of my tires and it is done (past wear indicator on one side). However, the other side still has a couple thousand miles left. I would like to use my spare to replace the bad tire for a month or two. I know that you would not want to run a different size tire on a limited slip rear end or in 4WD, however, I am near 100% that the rear end on my 2011 FX4 is open. I am sure of this because I was worried about not having a LS rear end and did research to make sure that my truck did have electronic slip prevention prior to buying.
So if my rear end is open, it would not hurt anything in 2WD to have different size tires on, correct?
The tires on my truck are 33", and the spare is 32.1". However, I don't have too much tread on the tire that I want to keep running, so the difference is probably around .4" in diameter.
I don't really want to put the spare/older tire on the front because it would be a major pain to move all 4 tires with my screw jack (yes, I know I should invest in a good jack) and jack stands.
FYI I got an alignment done when I got the front tires replaced in the spring.
My front tires are near new. On the rear, I had some very uneven wear on one of my tires and it is done (past wear indicator on one side). However, the other side still has a couple thousand miles left. I would like to use my spare to replace the bad tire for a month or two. I know that you would not want to run a different size tire on a limited slip rear end or in 4WD, however, I am near 100% that the rear end on my 2011 FX4 is open. I am sure of this because I was worried about not having a LS rear end and did research to make sure that my truck did have electronic slip prevention prior to buying.
So if my rear end is open, it would not hurt anything in 2WD to have different size tires on, correct?
The tires on my truck are 33", and the spare is 32.1". However, I don't have too much tread on the tire that I want to keep running, so the difference is probably around .4" in diameter.
I don't really want to put the spare/older tire on the front because it would be a major pain to move all 4 tires with my screw jack (yes, I know I should invest in a good jack) and jack stands.
FYI I got an alignment done when I got the front tires replaced in the spring.
Senior Member
Joined: Mar 2016
Posts: 127
Likes: 25
From: South Bend, IN
Is it a money issue as to why you can't replace the ones on the back? Seems like you are creating a lot of possible headaches for yourself. I'm just a shade tree mechanic, but I'd think you'd be able to do what you're asking for a little while but a few months seems like it would be MUCH longer than you should be doing.
5 Year Member
Joined: Apr 2016
Posts: 3,677
Likes: 1,722
From: Georgia
Regardless of 4X4 or open diff's it is best to replace all 4 tires at the same time. This is especially true with 4X4 vehicles. Even if you buy the exact tire in the same size a tire with 30K-40K on it will effectively be 1 size smaller than when new. Even on 4X2 vehicles having the same tires with the same amount of tread is advisable for handling reasons. Not necessarily because of a locking diff.
But sometimes you've gotta do what you've gotta do. I'd much prefer to have both tires the same on each axle. But for temporary use I'd advise being careful especially on wet pavement. But I'd correct the situation ASAP.
But sometimes you've gotta do what you've gotta do. I'd much prefer to have both tires the same on each axle. But for temporary use I'd advise being careful especially on wet pavement. But I'd correct the situation ASAP.