New Wheels and Tires, What do I do about the Spare?

I just purchased SCS SR8 (17 X 8.5/ 6 X 139.7/ 4.30"/ -10mm) wheels and 5 Falken Wildpeak tires (LT265 /70 R17). What do I do about the spare? At first, I thought I could just put one of the Wildpeaks on the spare wheel, but looking into the dimensions it has a different offset than the SR8s I purchased.

Is it a really bad idea to just swap the tire, or do I need to purchase another wheel? If so, any recommendations on a wheel that has the same dimensions but is a lower cost?

 

Assuming the spare is for emergency use only and isn't in a usage rotation, it'll be fine on the factory wheel. Really, since the tires are the same as OEM size, I'd be inclined to just keep the OEM spare tire and return the Falken.

Obviously differing offset isn't great, but for emergency use it's acceptable.

 

Really? That would be great! My only fear is getting a flat a few hundred miles from home and riding on a different sized tire the whole way back. I appreciate the reply!

 

The size you posted for the Falkens is the OEM tire size so the OEM spare is that size. I mean, there is probably slight variance in size due to tread on the Falkens but it's negligible.

 

This brings to mind a question I've had, and perhaps I can get an answer here. Sorry in advance for my ignorance. Let's say you blow a tire when the set has like 30k miles on them. Putting on a mismatched spare for a few hundred miles is one thing (is there really no harm doing that?), but what happens with the replacement tire? Like can you simply get a new one of the same brand/model and size (knowing the new one has more tread)? And would this make any difference between, say, an SR5 and a Limited? Reason I wonder is because when I owned a Subaru I seem to remember hearing that all 4 tires had to be the same to avoid damaging the AWD - so if you shredded a tire you had to replace them all. I could see being able to put a mismatched tire on the front of a part time 4WD, but I can't imagine that would be good when in 4WD. I'd appreciate any enlightenment. Thanks.

 

Mismatched size tires is not a good idea, ever. The spare needs to be the same size as all the tires. On the Subaru use the 5 tire rotation method. Could use the same on any vehicle really. I should do this but don't. I have the stock tire as a spare and I have BFG KO2's. They are the same size but I am sure there is some difference. This should not effect anything for the amount of time the spare is going to be used.

 

Just to be clear, are you saying that if I shred a tire on my T4Rs I should replace all 4 (like I would on my Subaru)?

 

No. I am saying that if the tires are the same size it should not effect anything for the short amount of time you will be using the spare. This is how I do it, I have 4 BFG KO2's and my spare is the factory Dunlop...but they are all the same size....

I am also saying that it would be ideal if you bought 5 new tires and rotated them....meaning you are not only rotating the 4 tires on the road, you are also rotating the spare into being used as a normal tire....a 5 tire rotation schedule... This way all the tires will be exactly the same and if you get a flat it definitely would not matter.

 

Sorry to maybe beat a dead horse. I get the 5 tire scenario. But let's say I haven't ever rotated the spare into the mix. Let me ask about two cases: 1. I have less than 2000 miles on all four tires. I shred one (can't be fixed - I need a new one). The new replacement is the same make/model/size. I can see that the tire wear on the other three tires may be insignificant enough so that a brand new one would not cause any problems to the drive system. 2. But let's say I had 30-40k on the four tires. Not sure how much tread will have worn off. The new tire is the same make/model/size. It has more tread, so its diameter might be significantly different. In that scenario I'd think I might not be able to get away with replacing one tire but I'd need to replace them all. Right? Now if I had been doing a 5 tire rotation all along I'd just make the new tire the spare, since the old spare has had the same wear as the other three tires.

 

You might could disprove your own theory: does the Subaru use a donut spare?

I shredded a Cooper AT3 with 15k on it in Alaska, and bought another one up there. That put me at 15k wear on 3 tires and 0 wear on one. I had no issues nor would I expect to.

I would not rotate in my spare tire. I do have the same size and brand/ model on my spare rim but I also have larger than OEM tires. Interestingly, the spare rim is 7" while my OR rims are 7.5" (wide), so my spare is going to be a little taller just by virtue of being squeezed on the rim more, not even considering the lack of tread wear also making it taller than the tires that are in use. And that's okay, too.

You guys are overthinking this...a lot.

 

My Subaru has a full spare. I don't rotate my spare either. Once, early in its life, I blew a tire and simply replaced it. Also within 15k miles. Now at 140k the transmission vibrates when I'm idling at a full stop. Maybe it's coincidence, who knows. But maybe it's because I drove 35k miles or more on 1 tire that was slightly different. Am I overthinking it? Okay, maybe I am. I'm just trying to learn...