Does your spare need to be the same size?

[offroad_nomad]

I thought this may have been discussed before, but nothing turned up with my searches.

Looking into getting a set of new BFG TA KOs (285/75/16) at $185 per tire. I'm trying to save some money on the spare and I hate dropping another $185 for a new 5th tire as the spare.

Can I get away with a used 265/75/16 with 50-60% tread remaining as a spare? Thanks.

 

[Pskhaat]

Sure, your differentials will get a little more of a work-out. That said, I wouldn't advise locking any axle or center diffs and buy a used full-sized spare. 285/75r16 or a worn 255/85r16 shouldn't be too hard to find...

 

[toy_tek]

It would get you off the trail but I wouldn't drive any significant distance with a different size tire. Although I see people driving around on their spare "donuts" all the time.

I had the same dilemma as you just last year - I bought 4 new and then snagged a used 285 for a spare. $20 off Craigslist... 2 miles from work.

 

[Spikepretorius]

I've gone the route of using two spares! They now get included in the tyre rotation schedule so I'll always have the correct size spare and will get full mileage out of them as a set of 6 so there's no wastage.

 

[AndrewP]

Totally legit to buy a used tire the same size. This gets done all the time.

Also, if your truck isn't fulltime 4 wheel drive, just put the odd sized tire on the front, and it won't affect your diffs at all.

My FJ60 has 33 x 12.5 tires, and the spare is 33 x 9.5 because it takes up less space.

I would not run different sized tires on a drive axle at high speed. That will work the diff a little too hard.

 

[eugene]

I vote for same size, as others said the slowe rspeed off road a different size won't hurt but once you get to the road then you run into issues.
The other advantage of a matching spare is 5 tire rotation, you get 20% more life from your tires since they each get a 'rest' 1/5 of the time, plus you know your spare is good, no more putting off digging it out to ckeck it then find out its bad when you need it.

 

[spray]

I think it comes down to where you 'wheel' and if you think you will need your spare. On my rig I have two spares and they are the same size as my other tyres (tires), but I do expect to use them as I can be 3-4hours drive from help when out camping. I have had trips were I have had 5 flats in 2 days driving old firetrails so I also carry a plug kit and compressor.



A good spare is cheap safety

 

[computeruser]

You can, but why when you can grab a used tire of the same size. Cheap insurance, and a seamless swap if the need arises. Sure, you don't anticipate needing it for long distances, on-road, etc., but it seems prudent to have a spare capable of doing that if need be.

 

[offroad_nomad]

Thanks for the input, I guess I'll continue looking for a used 285. I've been looking locally, on eBay, and offroad sites but no one seems to be selling a single used 285. I'll give Craig's List a try too.

 

[toy_tek]

Used 285's. {edit} didn't see that he's firm... maybe he'll split them up?
http://washingtondc.craigslist.org/nva/pts/760481095.html

Also check with your local tire shops. They'll hang on to decent used tires for resale - not all of them get shredded.

 

[tdesanto]

Get a full size spare at the same time. If you have your tires rotated for you at the place you buy them, then have them rotate the spare in. This can add another 5-10,000 miles out of the tires if done often and correctly.

$185/tire? That's good. I bought those exact same tires last year for $210ea at Discount Tire. At the time, this was one of the best prices in town.

Regardless, you're gonna love those tires.

 

[Carlyle]

One more humble opinion...

I ran with a used spare for several years when I ran 305's. I did bite the bullet recently and went with a brand new spare tire and wheel when I went to 19.5's. What a pain as I had to reroute the exhaust in front of the tire, but now I feel more confident knowing its there and I rotate it in with the other four.

Your choice, but always better to have the right size tire with you.

 

[Robert Bills]

Yes, you can use your old tire as a spare, as the general rule is that a spare within 2" of the bad tire on the ground will work, but a used tire the same size as your tires on the ground won't cost much.

I am now running 35x12.50/15 MTs on my CJ with a 33x9.50/15 AT as a spare. The smaller spare was necessary so that I didn't need to cut/reweld my custom rack/bumper (3 jerry cans mounted to the left and spare to the right) which was built for a 33" spare. Also, I didn't want to carry the extra weight of a 35" spare on a steel wheel (I'm an old guy and don't like to lift that much weight that high).

I have never needed to use my spare as every tire problem so far has been able to be solved with my Safety Seal tire kit and onboard air (knock on wood), but if I need my spare there is no problem using it on the front axle. (Rear axle has a Detroit locker, which makes things exciting with mismatched tires, so it might be extra work with an unrepairable rear tire to move a good 35" front tire to the rear and then the 33" spare to the front, but I figure my chances of having to do that are 50/50 and only if a tire plug (or plugs) won't do the job. As for my Lock-Rite locker in the front, it's not an issue in 2WD and in 4WD I can disengage the hub with the 33" spare.)

 

[MountainBiker]

I've gone the route of using two spares! They now get included in the tyre rotation schedule so I'll always have the correct size spare and will get full mileage out of them as a set of 6 so there's no wastage.

Yep, I do the same thing.

 

[jh504]

It was said before but I will add it in. Go to your local tire shops and ask if you can dig around in what they have. I bought a set of 33 BFG ATs a while back and when I got them mounted the guy had four of the same tire in the back he had just taken off another truck. I picked one up for free that had about 30% tread left. The best deal in town.
I never leave home without a full size spare, for me it is essential.