Well I've been driving for a living for over 15 years now and put over a million miles collectively on various company cars/vans alone and have never needed to touch one of my spares.... (Of course now that I've said this all bets are off I'm sure)

 

+1^ there's no real logic in needing a spare thats the same size unless you think your going to neglect swapping it out in a timely manner and plan on driving it that way for an extended time...
If there is some other concerns I'd like to hear the reasoning?

 

I can think of at least a couple reasons to do it beside the concern about ruining some part of your drive train.

My main reason is independence, ie from caring when you swap it back out of there since a spare is going to handle just fine if it's the same tire. Carry enough identical full spec spares and I wouldn't need any tire mechanics for quite a while with any luck. Ideally I'd have my trailer running identical wheels and tires as the truck for even more spareage flexibility. Edit: forgot to mention the point...no telling when flats strike while exploring but it's nice to know there is a backup plan when they do. Been there done that several times and I'm only 44. EDIT^2 remember you have to drive back to civilizatiion after you change the flat and there may be obstacles in the way.

Another popular reason I would imagine, though not particularly mine in this case, is as in racing: for speed and convenience, to accomplish all the performance needs asap. etc.

 

but thats just it.... its a spare tire for temporary use ... not replacing itr as soon as possible means you then have no spare while your using it and promotes procrastinating and not using it as intended...

Besides the possibility of LSD or locker issues if used on the rear axle theres nothing that holds water in saying you cant just use a smaller spare on the front in those cases to get back to "civilization".... Your splitting hairs here...bringing up changing flats while racing braving the unknown in extreme conditions and such... Really?

 

Huh? If my spare is equivalent to my normal tires why would I care how long I leave it on? Intended? What if I intend to leave it on after potting it on to replace a flat when I have it built? Would that somehow change something? Am I allowed to leave it on then ? lol As I pointed out my ideal scenario is with my trailer using the same wheel. Since in my vision of ideal my expedition rig includes said trailer, which would also be able to carry at least one maybe more spares, I would be set up with several spares to go through on any given fully outfitted adventure before being forced to high tail it to safety fr fear of a flat without a spare to replace it. When boon docking through say baja or someplace cool like that, or at least so the vision goes, where reasonable replacements may not be readily available, several spares may be exactly what is needed to keeps the party going.

perhaps your trips are always right past les schwabs and Firestones or whatever but we plan expand our horizons to places where tire stores stocking my special blend are no where near. heading into bfe and expecting the locals to come up with reasonable replacements for my particular blend of relatively difficult to source combo sounds like a recipe to get ripped off, severely delayed, or both..

Maybe you missed the part where I said the racing aspect clearly wouldn't apply to me...and coincidentally speaking of baja...most of the drivers of 4 wheelers in this seem to agree about the importance of a full size spare in baja...in a race. but yeah really. http://www.youtube.com/watch?v=s3aps...eature=related

 

i have been told if you are going to run a spare that is not the same size as the rest it is usually a good idea to put it on the front where it spin however it likes. i have been told if you run 2 different size tires on a rear end you can blow a bearing.

 

I wouldnt see how it would blow a bearing but I think it could mess up LSD clutches in posi rear ends only... The whole point is you would have to leave in on your truck for a long time

Ugly1, The idea is if the spare isnt just a matching fifth wheel a person is more likey to replace it with either their repaired tire or a new correct size one and not continue to drive around with the spare on the truck and blown tire in the back.......

And you get the benefit of more usable truck bed storage space or better cooling if its not hogging up your truck bed of hanging off the front of your truck making it look like something in Vietnam's waterways the other 99.9% of the time its not being used (if it ever is) I would think to most this would be an easy decision. (Well those of us not running a baja race)

 

I get why things are why they are. I still don't consider the situation ideal even if there is some valid logic behind doing it that way. In fact, I'm not even sure if my daily driver even has a spare. For me it's all about intended usage. The daily driver spends it's life driving around places where if it gets a flat it's no biggie to have fixed. I bought the truck to take me as far away from these safe places as I could reasonably get it to take me. For me a one size solution definitely does not fit all circumstances. I can't help but wonder if your tune might change if a punctured or pinched tire on a trail way up in nowhere left you stranded. I can tell you there are still places up here in the PNW where you'd rather have a ride back than be forced to hike it while trying to locate natural sources of sustenance along the way. Even if I'm up to the task of trying to live off the land (which I'd really rather not) while self rescuing/extracting it's not something I look forward to putting the kids through.

 

For the folks that go off-road on a regular basis, there is also the aspect of a smaller tire not giving sufficient ground clearance on some of the tougher trails folks take their rigs out on.....

Sure, for general use on-road, a smaller tire would be adequate to the task... although, if you have an automatic locker, or LSD in the rear, putting a smaller tire on that end of the truck would be a bad plan..... putting it on the front IS going to alter the way the truck drives as well.....

For my own personal use.... I keep a matched tire/wheel as a spare. If I have a flat, the spare goes on, the flat tire gets repaired, and then becomes the spare......