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tire question


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It's always best to run all four tires as the same brand, size, and tread wear.

 

Though you'll get along fine running two pairs of tires front and rear, IF they are the same size and have about the same amount of tread left. Do not engage 4WD on pavement if you're running like this.

 

Really wouldn't recommend running anything different than one set of four or two pairs, it can have some funky traction effects and prematurely wear out an LSD.

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You shouldn't lock it into 4wd at all on dry pavment.

As long as the tires are the same size, it is ok to have different brands, tread type on the car.

I did this for a while, had two missmatched snow tires on the rear, and two miss matched street tires on the front, and used 4wd with no problems. the tirs just have to be the same size.

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Ok, I will split the difference here.

 

To run in 4WD, you really should have (need) 4 matching tires of same brand/style. To run in 2WD only, this is not much of an issue.

 

BUT...

 

Tires that are nominally the same size aren't always actually the same size. I needed to put some tires on the front of my wagon that still had some tread, and "borrowed" a pair from one of my other projects. Same nominal size, but height is different by 1/2-1 inch. Put the car into 4WD on a rain drenched highway and went into immediate bind at freeway speed.

 

And just because the sizes match and/or you are running in 2WD does not mean that mixing is OK. Same wagon, same tire setup, the handiling is just plain squirrely. The front tires have a harder compound and less lateral stability; they spin on drive pavement and "hunt" into every groove and irregularity on the road. Meanwhile, the Michelins in back behave properly, which is no good with the fronts going there own way. My nightly drive home with sub-freezing tires on an oddly-grooved two-lane is quite exciting.

 

So, Jim, yes you can do it, and as long as you know what to expect YOU will do OK. I wouldn't recommend this for an inexperienced or less competent driver; too many chances to end up in a ditch if something else happens.

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well what i have decided to do is run my h-style rims which are all 4 the same size and wear, hay pat got my 3 door all fixed up and running , now have to make a decision , i have to sell aleast 2 of my subaru's , sell 3 door, and fwd sedan

I thought that you had already posted your 3-door for sale. Was I dreaming, or maybe psycho... er, psychic???

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well since the 4wd with open front and rear diffs, the torque transfer is spread diagonally, that is in 4wd, one front and one rear will be locked in, and the others will spin freely

 

aside from the difference in treads and being the same size, i would either put 2 like tires on one side of the car, or put one in front and the other opposite in back. that way you will have a tire each on each diff that will rotate at the same speed, and the difference in size for the other tires will be absorbed by the center diff

 

this is what i would do if the tires are and difference in size, or slightly different diameter for tires of the same size

 

anyway i can see what jim wants to do, keep like treads on the front axle for 2wd and steering.

 

if running 2wd the differences wont affect anything, and if you use 4wd on 4wd friendly conditions this would have little to no effect. i have different makes of tires on the sedan and it does fine in 4wd, like the snow, slush, or patchy conditions

 

honestly in my opinion from my understanding of the 4wd system's wotkings i wouldnt worry about the differences in make how you want to put them on the front and rear respectively. and if tread design want a concern with me i would put them diagonally from eachother

 

let them speculate but i have used 4wd with odd size tires, diagonally as long as each 2 sets are the same size to eachother

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let them speculate but i have used 4wd with odd size tires, diagonally as long as each 2 sets are the same size to eachother

 

I'll definitely buy into that. When I jsut scored the tires/wheels for my OBS, I chose to put the two most worn tires oposite eachother, rather than both on the front or rear.

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Miles, unless Jim put in an FT4WD (in which case we wouldn't be typing, would we?) he doesn't have a center diff. The front and rear are in lock-step. Your idea of diagonal sounds OK, especially in an emergency; I'll have to remember that one. :) However, the idea should only work right in a straight line; as soon as you turn, things should get worse then a front set/rear set setup. And the "slipping" only works if you are on something that will let you slip.

 

I haven't tried this, so I won't say it wouldn't work, just that it sounds off. And am pretty sure that mis-typed tires (mixed brands/treads) would handle REALLY weird on the diagonal.

 

Maybe I will go out and try it... :grin:

 

Later, Miles!

Pat

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yeah this could bind when turning but this would not be a problem on an appropriate surface that you would use 4wd on

 

my post leans more towards thery of how the system than practical use. but in an emergency if odd tires is all you had then what i posted would be the recommendation

 

if you had a flat in the woods and your spare was the wrong size, you can still use the 4wd since the open diff will absorb the difference, that is, 2 of the tires one on the rear and one on the front will still be the same size. going with 2 odd tires they need to be the same size to eachother, and one on the front, and one on the back

 

but again i have run odd size tires becuse that was all i had, and i like baja'n anyway, im telling from my own experiences about what you can do and get away with it

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