Mazda CX-9 AWD - replace two tires okay?

[panthermike]

So my wife accidentally hit a curb the other day, pretty hard. At first I didn't think there was any damage, but today while I was doing the brakes I noticed a gash on the sidewall of one of the tires. It is holding air just fine and riding okay, but I can see some of the belt so I'm thinking replacing it is the best option.

We put a set of tires on it about 13,000 mi ago and tread wear so far has been good. I'm hoping to avoid having to replace all four. Would it be viable to take the best 2 current tires put them in the front and put two new tires in the rear?

I've heard mixed things on this, but we have never owned an all-wheel drive vehicle before so thought I'd ask the experts!

 

[IndyIan]

You can measure the tread depth of your current tires, if they are down more than 5-6/32, you might want to buy some used tires that are closer to the depth of your current tires. If you've only got 2-3/32 wear, just get 2 new tires that are the same as the old ones and put them on the front for 13k and then rotate as you normally would.
I think you only can get into real trouble when the front axle spins significantly faster than the rear axle, which engages the rears.

 

[supton]

I want to say, I've seen 2/32's the limit for difference for at least one make?

I regret not getting 5 tires when our CRV needed tires, and just done a 5 wheel rotation going forward. Then I could pop a tire and just hope that I'd not need the spare until the next set of 5 tires.

 

[panthermike]

You can measure the tread depth of your current tires, if they are down more than 5-6/32, you might want to buy some used tires that are closer to the depth of your current tires. If you've only got 2-3/32 wear, just get 2 new tires that are the same as the old ones and put them on the front for 13k and then rotate as you normally would.
I think you only can get into real trouble when the front axle spins significantly faster than the rear axle, which engages the rears.

I'll measure for sure. Unfortunately the tire we put on was from Walmart that is currently unavailable. You think it might be ok to get two different ones?

 

[supton]

I'll measure for sure. Unfortunately the tire we put on was from Walmart that is currently unavailable. You think it might be ok to get two different ones?

Usual recommendation is matching pairs per axle. AWD complicates it by wanting same circumference per tire, but I don't see why unmatching tires would matter. If you are in Arizona and not dealing with anything than dry roads, then it likely matters not.

But they might wear at different rates. Might want to aim for the same tire wear rating, and to be aggressive on tire rotations going forward.

 

[krzyss]

What does manual say?

Different model of tires is as big 'no, no' (most of the time) as the sizes are nominal so you combine different circumference with different traction.

Krzyś

 

[slacktide_bitog]

See what kind of deal you can get with the Black Friday sales. It might actually be worth buying 4 new tires anyway if the deal is especially good

 

[panthermike]

What does manual say?

Different model of tires is as big 'no, no' (most of the time) as the sizes are nominal so you combine different circumference with different traction.

Krzyś

Just checked, they recommend replacing all 4.

 

[panthermike]

See what kind of deal you can get with the Black Friday sales. It might actually be worth buying 4 new tires anyway if the deal is especially good

Good idea! Anyone know of any good sales happening?

 

[JohnnyJohnson]

If tire size is so important how do they get away with giving you that pee wee spare?

 

[Pelican]

Check with the dealer as different size tires may affect your ABS some systems would be and some wouldn't.
There is some variation margin that makes it still safe, but that varies from vehicle to vehicle.

 

[Propflux01]

If tire size is so important how do they get away with giving you that pee wee spare?

because you can put the Pee Wee spare on a rear wheel position long enough to get to a station (30-50 mile-ish) do not put a temp spare on the front. If your flat is on the front, move the rear wheel to the front and put the spare on the rear wheel.

 

[edyvw]

If tire size is so important how do they get away with giving you that pee wee spare?

Temporary. The damage to AWD happens over thousands of miles.
They assume you will drive to the first tire shop.

 

[Gasbuggy]

Won't discount tire shave a new one down to match?

 

[Cherrybomb]

In the scheme of things,I would measure the circumference, see if somebody can shave to that size.Then you just buy two.But if thats not an option,get the allowable difference from your dealer.4 tires is better than messing up your car.Thats why tire rotation service is very important on awd vehicles

 

[berniedd]

Generally, AWD requires all 4 tires to have the same circumference for best results and longevity. That's why regular tire rotation is advised to equalize wear on all 4. Can't you find a used/junkyard tire that matches your other 3? Or you could replace all 4 tires now, and sell the older 3 tires.

 

[krzyss]

Just checked, they recommend replacing all 4.

What kind of AWD CX-9 has?
If it has center diff then you will need all 4.
If it is Haldex or similar it may be OK to replace 2.

Unavailability of the same tires and need to have 2 old and 2 new different ones would steer me for 4 new the same tires.

They will be different size, different traction - all bad signs for any AWD.

Krzyś

 

[Jetronic]

So my wife accidentally hit a curb the other day, pretty hard. At first I didn't think there was any damage, but today while I was doing the brakes I noticed a gash on the sidewall of one of the tires. It is holding air just fine and riding okay, but I can see some of the belt so I'm thinking replacing it is the best option.

We put a set of tires on it about 13,000 mi ago and tread wear so far has been good. I'm hoping to avoid having to replace all four. Would it be viable to take the best 2 current tires put them in the front and put two new tires in the rear?

I've heard mixed things on this, but we have never owned an all-wheel drive vehicle before so thought I'd ask the experts!

If you're only replacing 2, put the most worn tyres on the back. If the rears are turning slower than the fronts, the AWD will try to kick in (in general terms, maybe Mazda does it different but don't bet on it!). But that causes such a strain you are likely to break the AWD system. Can't count the amount of Tucson and Santa Fe that broke their AWD this way, sometimes with a bang but often without signs.

Worst thing to do was a different model tyre fitted on each axle.

 

[Jetronic]

If tire size is so important how do they get away with giving you that pee wee spare?

Hyundai gave full size spares back then, or no spare at all.

 

[panthermike]

What kind of AWD CX-9 has?
If it has center diff then you will need all 4.
If it is Haldex or similar it may be OK to replace 2.

Unavailability of the same tires and need to have 2 old and 2 new different ones would steer me for 4 new the same tires.

They will be different size, different traction - all bad signs for any AWD.

Krzyś

Not sure on the type, I'll have to look into it.

I think I've decided to just go ahead and replace all 4. Unfortunate but it's ok!