Good afternoon, guys. I posted about a week back about some unrepairable sidewall damage incurred on my Dunlop Grandtrek tire. I toyed with the idea of getting 4 new Revos, but that is out of my current budget. What I think I will do is mount my Grandtrek spare and purchase a used tire of the same size to use as a spare. An expenditure of roughly $50 as opposed to $600. Will I have problems running a new tire if the others have 38k on them? Does this pose any harm to the vehicle?

 

Jeff
I think some else said this: buy a new tire and get it mounted instead of the flat. Replace the used (non flat) tire by mounting your spare (if same size) on the same axel. Finally put the used (non flat 38K tire) on the spare.
You should ideally have the same size tires on the axel (I don't think you be saving money in the long run if you run different sizes). I think if you just add another used tire they will not match up. So you will have to pay for one new tire and mounting.
C
BTW: Just got the revos on, awesome in the serious rain we have today here

 

Why would you recommend this method? The spare to be swapped with the damaged tire is identical. Same make, model, and size. Only difference is that it has fresh tread, whereas the other three have about 38,000 miles on them. I just want to know if this could pose any harm to the differential or anything else.

 

That difference (fresh to used) could be hard on the diff (someone correct me if I am wrong, but I thought it could wear it out). The price of new diff has to be more than a new tire. So you need another tire of same size (ie new, maybe someone here has a new spare they don't want). Potentially a new and used tire will have different traction too. That is why I recommend getting a new tire. How much are the Grandtreks?

PS: I tried doing some searches and most people say replace two tires, but in some cases you could just replace one if the other tread is still good. At 38K that is up to you to decide (my last set only lasted about 30K)

 

Just stick the new tire on the front and keep it out of 4x4 unless on slick surfaces, which you should be doing anyway. Then go drive the vehicle and quit philosophizing.

 

get teh new one, and put the spare onto the same axle as the new one if the spare is new, make the most worn out tire the new spare...

 

I'll 3rd that motion. Buy one new tire and put the spare on the ground!

 

And to be realistic, you will not ever affect an open differential by such a small difference as a worn tire.

 

agreed.

 

I second that.

 

OK. So I'm getting some mixed opinions here. I can either buy a used full size replacement spare and spend $25, having the damaged tire removed and mounting the former spare in it's place. The other option is to spend $110 and buy a new Grandtrek to mount on the other side if the rear and move the Grandtrek with 38k miles to spare duty. I am getting a bit nervous about this differential stuff.

 

One more opinion to muddy the water...

You've gone from wanting to spend over $600 for new REVO's to buying one inexpensive tire. You're going to need to replace all 4 in the near future anyway, so depending on your driving style and location, there are a lot of very good tires to be had for well less than $100/tire. I say find a decent tire and spend the money to do it right. You'll be good-to-go for the next 40-60k miles. Otherwise, when it comes time to replace another tire (soon?), you'll be in the same dilemma.

BTW, no damage to the diff with same size tires on the axle with one worn or not.
FYI, I just replaced my REVO's (definately a great tire!) with Firestone Destination LE's. I decided that I didn't need that caliber of off-road traction (I don't off-road) even though I do drive back country snowy roads. The Firestone Destination LE's have the silica that give the REVO's such good wet traction and were about $50 less per tire. And, if you weren't aware, Bridgestone and Firestone tires are made by the same company.

 

IMO tires should be replaced at least in pairs since the mileage difference is so great. Buy a new tire to match your new spare, put them on the matching rims and use the good tire you take off as your spare and junk the screwed up one. Then when the other (2) wear out shortly, but (2) more...

It kills me how folks want to skimp on tires when they are the only thing touching the pavement...

 

The green smiley is the "dead horse"!!! LOL

 

Jeff_M, here's a perspective from which you can draw your own conclusions:

Let's say you have a one brand new 31" tire.
And you have one used 31" tire that has 40% of its 15/32" tread left, so it is a 30.625" tire now.

Lets say you mount the smaller tire on the passenger side, and the bigger tire on the driver's side and start driving clockwise in a circle.

With the mismatched tire combination mentioned above, if you drive inside a circle with a diameter of ~914 feet both tires will rotate at the same speed.

Based on that, if you drive straight with the mismatched tires, you are placing as much strain on the drive train as you would driving within a circle of 914 feet diameter with a pair of matched tires.

<After wasting so much time on math in school I could not pass up this opportunity. >

 

Why would you call my options skimping? What would you do if you were in my shoes? I refuse to buy a set of Revos at this point (I will in the somewhat near future) when I have ~15,000 miles left on tires that have been perfectly serviceable thus far.

 

My apologies, I wasn't trying to insult you personally...so please forgive me. If I were in your shoes...I would do exactly what I mentioned above...as that is what I did when I was exactly in the same situation.