Tire tread question (comments welcomed)

[AV8R4AA]

On my 2003, the previous owner didn't replace all 4 tires as a set.
The fronts are more worn than the rears.
My tire ship here (Discount Tire) tells me that with all wheel drive
vehicles, its best to replace all 4 at the same time.
I have the 20 inch wheels and Nitto tires.
I am thinking of buying those again, because my Hi dolla Michelins
are barely going to make 25K.
What is this forum opinion on that?

[Crowz]

I will be buying tires soon and so far its between Michelin or cooper after reading ratings all over the net.

The Michelin's weren't that bad at 170 or something each but Im used to buying tires for my trucks at almost 300 a tire so all car tires seem cheap after that

For cheap tires I like the Ohtsu tires I put on my wife's 528i. Killer mileage and pretty good traction in rain and mud. I didn't see an exact match size wise for the X5 wheels I have on mine looking them up just now but they have ones that are close. Average price on them are from 75 to 85 dollars.

[jdstrickland]

It's true, you're better off replacing all 4 tires. This is a general rule of thumb that has pretty much nothing to do with AWD. I have Bridgestone Duelers on my X5, they are supposed to give 80,000 miles. I have no complaints with them.

[oldskewel]

2 separate issues to consider: AWD balance of rolling diameters = to protect the transfer case, and front-rear grip imbalance = handling / safety concern.

The AWD expects equal rolling circumference on all 4 wheels. There is a spec on allowable difference front to rear - I can't remember what it is off the top of my head.

Obviously when the tread is new, vs. bald, you'll have a slightly different radius / diameter / circumference.

Generally, if you stick with the spec'ed sizes, the variance in tread depth will still keep you in-spec regarding the front-vs-rear rolling distance variation limit ... which BTW is to keep the transfer case from working too hard to keep you rolling.

It's some pretty simple math to calculate the circumference from tire size and tread depth remaining (but don't expect the online calculators to do that for you). You can do that and see if you'd still be within spec. I actually did this when I was considering buying a slightly different tire size with new tread (would have been a great deal) to match with my less-worn fronts. I passed on that and have the regular sizes for 19" front and rear.

"(Discount Tire) tells me that with all wheel drive vehicles, its best to replace all 4 at the same time." - whenever I hear something like that, I wonder "best for whom?". Sure this is best for the tire shop, maybe not for you.

And completely separately from the AWD concern, there is a stability issue for front vs. rear. For stability (not spinning out), you generally want equal grip front and rear, or more grip in the rear. If you have more grip in the rear, you may under-steer as the fronts slip a little more. That will be a little annoying. But if the rears have LESS grip, you will over-steer, which in the extreme may be a safety issue if it makes you spin out.

[X53Jay4.8is]

Originally Posted by AV8R4AA

On my 2003, the previous owner didn't replace all 4 tires as a set.
The fronts are more worn than the rears.
My tire ship here (Discount Tire) tells me that with all wheel drive
vehicles, its best to replace all 4 at the same time.
I have the 19 inch wheels and Nitto tires.
I am thinking of buying those again, because my Hi dolla Michelins
are barely going to make 25K.
What is this forum opinion on that?

I am surprised that you have 19" on the 2003 4.6is X5. I thought all of those were equipped with staggered 20 inch wheels?

[AV8R4AA]

Originally Posted by X53Jay4.8is

I am surprised that you have 19" on the 2003 4.6is X5. I thought all of those were equipped with staggered 20 inch wheels?

Correction

[bcredliner]

Some drivers like a little underwater, some neutral and some love oversteer. There's a lot of personal preference in handling characteristics. Personally I prefer a just a little oversteer. But, doesn't matter much what it does unless your are pushing the handling limits. The X5 suspension is not designed for oversteer and I think handling limits will be compromised if you can find a setup that results in oversteer. You mentioned the tire question is for the 2003. If that is your 4.6 it should have 20 in staggered rims. Over the years I've tried many different combinations. I have always gone through two pairs of rears to one pair of fronts. Most of the time even when changing brands I only buy the two I need. Tread wear differences are not an issue if you are staying with OE sizes. Currently I'm running Continental Extreme Contacts. Very close to the best handling tire but certainly best all around tire I have run. That's based on ride quality, handling, wear and price.

[X53Jay4.8is]

The Continental DWS is a fine tire for the handling of these X5s and wear nicely too. Their price is not exorbitant as some of the other brand tires.

[Crowz]

Originally Posted by X53Jay4.8is

The Continental DWS is a fine tire for the handling of these X5s and wear nicely too. Their price is not exorbitant as some of the other brand tires.

I started to buy those but they don't come in the size I need. I have 17's

225/45ZR17 91W is the only 17 inch size they show


On 20's the op has this is the only size they show

255/35ZR20 97W

[dkl]

Originally Posted by Crowz

I started to buy those but they don't come in the size I need. I have 17's

225/45ZR17 91W is the only 17 inch size they show


On 20's the op has this is the only size they show

255/35ZR20 97W

That's not quite correct. I found this on TireRack