# AWD tire question



## jaye944 (Jul 5, 2015)

So, can anyone confirm what I would need to do,.

IF I have an un repairable flat, I would usually change out both tires on the axle and put the new ones on the rear

But I am also seeing that I "must" replace all 4 if say 2 are low
I am running square, what about staggered ? as I can't rotate them, 
Can I only replace 2 at a time ? or again all 4

if I have square set-up, can I go to staggered, do I need to tell or programe anything on the car ?

txs !


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## u.nanimous (Nov 1, 2014)

Since you have xdrive...you could buy a new tire and have it shaved to match tread depth but that is full price plus extra labor,. Or you can buy a used tire, you can search within a couple 1/32's and they are usually half the cost.
Another option would indeed be buy 2 and put them on the rear, but if you switch to staggered the wide tires go on the rear and it works best with staggered size rims.


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## jaye944 (Jul 5, 2015)

I've seen some questions/answers about AWD saying you "must" replace all 4 tires ?
is that true ?



u.nanimous said:


> Since you have xdrive...you could buy a new tire and have it shaved to match tread depth but that is full price plus extra labor,. Or you can buy a used tire, you can search within a couple 1/32's and they are usually half the cost.
> Another option would indeed be buy 2 and put them on the rear, but if you switch to staggered the wide tires go on the rear and it works best with staggered size rims.


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## HotGrbg (Apr 23, 2021)

No. There is some tolerance accounted for. The max difference is 6.35mm or 1/4 inch difference all around if you ask bmw about warning lights, Xfer case damage or DSC intervention scenarios but I think the “spec” in the book is 3mm in any tire or difference in the set.
Tires come with different tread depths as new but I’d say the average is 8mm. So if your worn under 5mm then a set or shaving a tire is a good idea.
basically if your tires are fairly new you can do 1 of the same brand/model tire.
If your tires are older/worn close to 1/2 way you should at minimum do 2.
If your tires are bald…cmon man. Do a set 😆
I’m sure there’s a few out there to try and prove me wrong here but this is how it’s done in the real world regardless of what an ISTA page says.


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## Autoputzer (Mar 16, 2014)

BMW requires no more than 2mm (2.5/32" difference in tread depths for xDrive. But, some of the staggered sizes on xDrives have more than 5/32" difference in their theoretical rolling diameter at full tread depth. Audi and Subaru (Scooby Doo) also have strict tread depth difference limits. Any difference in the average front and rear rolling diameters puts a slow, steady grind on the clutches in the xDrive transfer case. The ideal difference between average front and rear rolling diameters is zero. 

Because it's the difference in average front and rear rolling diameters that matters, replacing two tires on an axle puts more stress on the xDrive transfer case clutches than just replacing one tire. But, different tread depths on an axle can cause asymmetric hydroplaning. Also, a tire's traction diminishes with age. So, BMW also requires tires have no more than four years of age difference.












Even with xDrive, the rear tires will usually wear faster, but less so than with sDrive (RWD). The nice thing about a square set-up is that with frequent rotation you can keep the tread depths front and rear nearly the same. After 29k miles and frequent rotation, the average front and rear tread depths on Frau Putzer's X3 xDrive 30i are within 0.1/32" of each other.

I duh know of Tire Rack operates in Canukastan, but they'll shave a new tire for about $35. 

There's some math behind the decision to replace one, two, or four tires, You can calculate how many "tire-lives" you're throwing away. If your tires are at 50% remaining life, and you shred one, replacing that one shredded tire with a shaved new one would throw away 0.5 tire-lives, specifically throwing it away by shaving it off. 

If your tires are at 10% of remaining life, shaving that one new replacement tire down to 10% would throw away 0.9 tire-lives. But, replacing all four tires would only be throwing away 0.3 tire-lives (3 old tires x 0.10 remaining tire lives per tire). So, replacing all four tires would normally be the better choice in this case.

There's always some risk with used tires. but it's a cost effective way to replace one tire and still have roughly matching tread depths. The best place to buy used tires is the apply named BestUsedTires.com. I duh know if they operate in Canukastan either, though.

I avoid staggered set-ups so I can rotate my tires and replace all four at the same time and with all four of them being totally worn out. But, staggered set-ups help keep a car pointed in the right direction as you trail-brake into a turn. BMW's Legal Department is a big fan of staggered set-ups. That's because juries tend to blame a BMW going off a cliff backwards on BMW, and a BMW going off a cliff forward on the driver. Staggered set-ups also look cool. I suspect that's what sells a lot of M Sport Packages and Performance Tire Packages.


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## jaye944 (Jul 5, 2015)

hey wow, a lot to take in... so let me ask some maybe fundamental, maybe stupid so "PLEASE" bear with me

in the UK we NEVER do/did tire rotation... "TYRE" and we never did snowies either 
coming to Canada, I learnt about tire rotates and snowies
all cars to this point have all been RWD, (Neon ? hmmm maybe that was FWD)

I never did ANY tire rotations, because I'd rather buy a set of 2 than a set of 4. 
*<PUT ALL THAT ASSIDE IN THE BOX OF THOUGHT>*

So, with "MY" specific car (SQUARE SET UP)

1> Is is a MUST that I should tire rotate (every season winter/summer tire change)
2> If I find that the fronts (or the rears) are need replacing due to NOT tire rotating, I must change ALL 4
3> If i find the difference is too big (from the above data) due to NOT tire rotating, I must change all 4
4> Is there any or has anyone heard or seen of any stories on line where the if the above advise is NOT taken then the tranmission parts will grenade ?
5> Is this warrantee effecting ? 

Hypothetically IF I went Staggered

1> I can't rotate back to front only on each axle, so how does that help me ? I guess it doesnt


Finally I read/heard/googled that staggered is just purly for looks (on road cars) on VERY HIGH Performance, tracked or race cars, NO, but on your average 40km up the highway and back home it's just stance porn

txs


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## jaye944 (Jul 5, 2015)

ok on the tire rotate I think I found the answer, basically YES

*Do you rotate tires on All Wheel Drive Vehicle?*
It is necessary because regardless of tire and vehicle type, each wheel position on an AWD platform sees varying degrees of driving traction and steering.
Regular intervals of tire rotation between every 5,000 to 7,500 miles will maximize tire life and provide the best available traction and handling balance for the vehicle as well as rest of mind for the driver.
More importantly, AWD (all-wheel drive) or four-wheel drive autos need tire rotation the most because there is a huge difference in the tread depth on the 4 wheels, putting an additional strain on the car’s drive train.


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## ard (Jul 1, 2009)

Do not believe what autoputzer has posted…. BMW themsevles doesn’t follow this advice (and he even admits it in his post) but then slavishly follows there BS advice.

If the tires are within 50% you are fine.

some shot answers: if yoo change tire sizes to unapproved or incorrect sizes (ie the rolling diameters are not matched) then BMW _can_ deny warranty coverage if they determine that caused your issue. Ive seen this happen in other cars, can’t recall a warrant denial in a bmw.

you don’t “have” to do anything, Wear pants, rotate tires. I rotate my squares to even our wear. All my own decisions…

Tires wear out for all kinds or reasons. It is beyond me how you will determine that your tires wore out ‘due to not rotating’……


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## jaye944 (Jul 5, 2015)

@ard txs man,
I measure my tires depth and pressure monthly, 
If you don't rotate your tires, one set will wear out faster than the other, front or rear, think the driven ones.
which is why I only replace my tires in pairs because I don't rotate them


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## HotGrbg (Apr 23, 2021)

I’ve actually found it difficult to give advice around the forum. No matter what you say someone wants to jump in and argue and post ISTA pages but to @ard s credit some of this stuff is not followed…but how do you argue printed word directly from BMW in a medium that’s spoon fed to believe everything BMW puts out? Frequently they contradict themselves and countless times ETMs and SIBs have bad info until they are revised. 
Basically you can’t and the “safest” bet to to just quote what bmw states so you don’t get roasted and lose forum credibilty


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## Autoputzer (Mar 16, 2014)

I have Conti' DW's (summer, high-performance tire) on my Chevy Cobalt SS. I throw it around a lot, probably more than my 535i. Because it's FWD, the front tires are doing almost all the work: During my last 6k mile rotation stint, the front tire wore about four times as much as the rear tires. I got 40k miles on my first set of DW's, and I could have got maybe 5k miles more if one of them didn't have a puncture repair fail. 

Toward the end of the first set of DW's lives, I got corn holed at a stop light by Billy Bob. Part of his insurance company's adjuster's report was assessing the overall condition of the car. That included measuring the tread depths. The tires were down to near 4/32" of tread left, but all of the tires and all of the circumferential channels were near 4/32". After measuring all the tires, he said "Wow, I've never seen that before."

Most current Chevy Cobalt owners are not really interested in achieving tire wear perfection. They're more interested in finding some more meth' or crack.

In addition to tread depth, the loading (weight of the car, occupants, and cargo) on the tires and the tire pressures also affect the rolling diameter (twice the distance from the center of the wheel to the pavement. *Zero is still the optimal difference between front and rear average rolling diameters to minimize xDrive transfer case clutch wear... *assuming the front and rear final drive ratios are the same. (I suspect the 992-platform Porsche Carrera 4S has slightly different front and rear final drive ratios to compensate for the different front and rear tire rolling diameters.)

I've got the tread depth thing down to zero (currently less than 1/320" difference between front and rear). Frau Putzer's X3 spends most of it's life with one or two people in the front seats, and usually with very little in the cargo area. So, it's close to 50/50 weight distribution. Based on comparing the average side circumferential channel wear to the average middle circumferential channel wear, I've deviated from BMW's recommendation of 32 PSI front and 35 PSI rear to 39 PSI front and rear. So, I've got closer to that perfection of zero difference in average front and rear rolling diameters. I'm not saying I'm at perfection, just that I'm as close as I can be.

Anytime the xDrive partially disengages the clutch that sends torque to the front axle, there's going to be clutch wear. But, that's also what makes xDrive work. 

It's only snowed once here in Bubba County in the 26+ years I've been here, that was only for a few minutes, and none of it stuck to the pavement, or even the grass. But, we have sand. Frau Putzer's X3 has only gone a few hundred feet through sand, but it made it to the other side. The back entrance to Bubba Estates was blocked by a construction dumpster sitting in the middle of the road. I'm not sure why it was in the middle of the road, but there it was. Questioning "why" about too many things in Bubba County will drive you crazy. The garbage company's truck was there to move it, but nothing was really happening. 

My girly-man neighbor in his FWD Honda CR-V was patiently waiting for them to move the dumpster. But, because I had xDrive I drove through the sand (with some weeds growing in it) around the dumpster and back onto the road on the other side of the dumpster... *because I am an xDrive manly-man! *

We got xDrive because we're eventually moving 500 miles north and 1000 feet up in altitude, will be living on the top of a steep hill, and we'll have about a half-dozen snows per year.


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## Autoputzer (Mar 16, 2014)

jaye944 said:


> @ard txs man,
> I measure my tires depth and pressure monthly,
> If you don't rotate your tires, one set will wear out faster than the other, front or rear, think the driven ones.
> which is why I only replace my tires in pairs because I don't rotate them


I turn tire rotation into "a thing." In addition to rotation, I measure the tread depths with an electronic tread depth gauge with 0.001" resolution, wash the inside of the wheels and tires, and even put tire splooge (Meguiar's Endurance) on the inner sidewalls as well as the outer sidewalls. When the hot mommies in Bubba Estates walk by my open garage on the way to the mailboxes, I'm sure they think I'm a genius..


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## jaye944 (Jul 5, 2015)

I always appreciate your posts and advice without a doubt. I've been often on many a forums on both sides of the fence. Roasted more times than I can to remember and also roasted to. It's part of the elaborate dance we do. Do continue to post without fear, to re-quote barnum, "you can be right some of the time, you can be wrong some of the time, but you can't always be wrong all of the time" 

I'll be honest I often quote TSB's and ISTA till the cows.

A funny story.... on the Porsche forums' MANY YEARS ago, I was into Porsche TSB as if it were the very word of God.

On the 944S2's and 944's there was a TSB saying Porsche did not condone 18" rims on cars, only 16" it was dangerous. There were constant fights about I've been driving for years and nothings happened and a LOT of people backed me up in forum fights. BUT I was WRONG and RIGHT. While quoting TSB's NO-ONE EVER looked at the country of origin or what region it applied to.. it applied to NA and NOT ROW

(after speaking to a technical engineer) The TSB was RIGHT, for NA models but not relevant to ROW. The TSB was siting rules and regulations that NA cars due to number plates, heights of cars, suspension all kinds of things and in NA, 18" rims WOULD indeed cause an issue because of curb dimensions, in the UK we DID NOT, he drew me a technical diagram from the TSB, clearly showing on a 18" rim on a NA car it "could" cause problems, and may cause somone to sue Porsche. Would never happen in the UK or indeed any ROW model.

I learned then that it is not necessarily the INFORMATION / TSB / ISTA that is right or wrong, it depends on the region, country, model and applicable laws and if somone is going to get sued.



HotGrbg said:


> I’ve actually found it difficult to give advice around the forum. No matter what you say someone wants to jump in and argue and post ISTA pages but to @ard s credit some of this stuff is not followed…but how do you argue printed word directly from BMW in a medium that’s spoon fed to believe everything BMW puts out? Frequently they contradict themselves and countless times ETMs and SIBs have bad info until they are revised.
> Basically you can’t and the “safest” bet to to just quote what bmw states so you don’t get roasted and lose forum credibilty


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## cclcal (May 9, 2006)

im in a similar boat - except staggered setup. Had car for 1 week, only drove 30 min home from dealer. Noticed a small 1cm bubble/sidewall separation from bead on left front. I did not hit anything. Wife drove it once but doesnt recall hitting anything, maybe pothole, unsure.
Changed tire to yokohama advan as+ which has 11/32in tread depth (no choice because i had to leave town same day), there is a 3mm tread difference (6mm diam) from other tires. Went to tire store to exchange tire for PS4S or PSS (out of stock) both have 9/32 tread depth. this will match my other tires much better which only have 7000 miles.
Awaiting on tire store contacting Michelin for possible warranty or goodwill.


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## jaye944 (Jul 5, 2015)

YIKES !

Here in Canada we are plagued by potholes, even when trying to avoid you sometimes can't help it, when you hear that sickening thud, I almost expect to here see or feel something. of course I hadn't thought about bubbles. I guess there's something to be said about smaller wheels with thicker sidewalls after all ! LOL

Dammn it the other thing is it'll throw off the alignment, another $300 there






cclcal said:


> im in a similar boat - except staggered setup. Had car for 1 week, only drove 30 min home from dealer. Noticed a small 1cm bubble/sidewall separation from bead on left front. I did not hit anything. Wife drove it once but doesnt recall hitting anything, maybe pothole, unsure.
> Changed tire to yokohama advan as+ which has 11/32in tread depth (no choice because i had to leave town same day), there is a 3mm tread difference (6mm diam) from other tires. Went to tire store to exchange tire for PS4S or PSS (out of stock) both have 9/32 tread depth. this will match my other tires much better which only have 7000 miles.
> Awaiting on tire store contacting Michelin for possible warranty or goodwill.


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## jaye944 (Jul 5, 2015)

Hey guy's, I asked my tire guy about this situation.

"I've seen guys with staggered set-ups and they usually run the rear tires near bald, while the fronts are barely worn down. *You shouldn't have a problem if you don't want to rotate.* We just don't recommend rotating tires left-to-right.

The big risk with buying in pairs is if the tires are discontinued by the time you need to buy another pair. Next thing you know, you'll be buying a new set of tires and have a pair of decent ones that you'll be selling for nothing on the Internet."


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## Autoputzer (Mar 16, 2014)

I'm not sure where you're going with this.

BMW's been all over the place on rotation: don't, front-to-back only, side-to-side only, and "consult a BMW center."

My E46 M3 came with staggered, directional tires. So, I could not rotate them at all.

If you want to wear out all four (or five) tires at the same time, have a square set-up and follow the appropriate (FWD or RWD) four-tire or five-tire rotation pattern. Ideally, you want eight rotation stints with each tire on each corner of the car for two stints.

Since retirement (no more commuting or business travel), my "constraint" with tires is that they usually age out (six years) before the tread's worn down. We're sort of in a situation of "Which car should we take?... Let's take the one with the oldest tires." So, it's beneficial for me to wear out all the tires on a car at the same time.

If you want to minimize the slow, steady grind on the clutches in your xDrive transfer case, have a square set-up and rotate the tires regularly, keeping the tread depths and therefore rolling diameters differences as low as possible.

Because I take left turns considerably faster than right turns, the right-front tires on all my cars wear faster than the left front tires. So, if I had a staggered set-up, side-to-side rotation would be of some benefit. Uneven wear due to minor alignment differences would also be mitigated by side-to-side rotation on a staggered set-up car.. 

Tire rotation also mitigates "feathering" of the tread blocks.

The main reason performance cars have staggered set-ups is to induce understeer. That especially helps when you're braking into a turn ("trail braking"). A staggered set-up also improves acceleration when the constrain on acceleration is traction. That's why dragsters have big-ass tires in the back. Staggered set-ups also look cool. 

Staggered tires do increase the chance of a puncture. Most punctures happen in the back. That's because a nail or screw laying harmlessly in the road on its side is run over by the front tires. That causes the nail or screw to start tumbling. If it's upright when the back tire hits it, you're... well... nailed or screwed. If 75% of punctures occur on the rear tires, and the rear tires are 12% wider than the front ones (typical on BMW's), staggered tires increase the chance of a puncture by 9% (0.12 x 0.75 = 0.09).


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## Doug Huffman (Apr 25, 2015)

Same for bicycles. Vast majority of flats are on rear for that reason.

The Bicycle Wheel by Jobst Brandt


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## jaye944 (Jul 5, 2015)

This from bridgestone Tire Rotation: How and Why to Rotate Your Tires | Bridgestone Tires
I have square setup with directional tires, so rotation is Front-to-back / if I went staggered , side to side ?
Most rotations are X-pattern for non-directional
Is Bridgestone wrong ?
*FOR HIGH PERFORMANCE AND DIRECTIONAL TIRES:
1. SIDE-TO-SIDE (FOR DIFFERENTLY-SIZED PERFORMANCE TIRES ON THE FRONT AND REAR AXLES)*
All tires are switched with their same-sized partner and remain on the same axle. The two rear tires switch to the opposite side with one another while the two front tires do the same.
*2. FRONT-TO-BACK (FOR DIRECTIONAL TIRES)*
All tires are moved from one axle to the other but remain on the same side of the vehicle. For example, the front left tire is moved to the left side of the rear axle while the rear left tire is repositioned on the left side of the front axle.

-----------------------------------------------------------------------

As said, stagger is mainly for the look, on dragsters, track cars, race cars, some high performance cars,sure, on your toyutah, or civic for a daily poodle up to 7-eleven to get a coffee and doughnuts, it's just so you can make your car look Sic !  To get the benefit of that, you have to drive it like you stole it, 30mph, or 50 kph, seriously ? Your telling me that stagger is doing some kinda magic LOL

On the 128 I had square for winter and stagger for summer, and the stagger'd sucked, even when driven hard, I would often break away (doing my starsky and hutch bit, pulling a left or right hand turn) or worse just sliding in the wet. The winters were Kumho's and summers were conti's, now the AWD is a beast on both acceleration and when I throw it around a bit  there Pirrelli's 






Staggered vs. Square Tires | TireBuyer.com


A staggered tire setup is one in which the front and rear tires are different sizes. When the tires are equal at all four corners, and there is no tire width difference between front and rear axles, the setup is square.




www.tirebuyer.com




*Staggered tire setups are perhaps most common with performance vehicles – for example, Chevy Corvette, Ford Mustang, BMW M3, Mercedes-AMG, Porsche 911, etc. In these vehicle applications, specific staggered tire setups are selected to deliver performance and particular handling balance/characteristics.*

------------------------------------------------

In my experience and from memory as I don't have lot's of punctures, every one I had certainly in canada while driving the caravan and the neon, has been up front, 
including the recent slow puncture I had in the 128, last year or so (which I posted on here in fact), I can't remember back to UK days, but don't remember any rear ones, I used to have a company car and done a gazzilion miles on service calls.

----------------------------------------------------

But on the "consult a bmw centre" that's always good advise.





Autoputzer said:


> I'm not sure where you're going with this.
> 
> BMW's been all over the place on rotation: don't, front-to-back only, side-to-side only, and "consult a BMW center."
> 
> ...


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## Autoputzer (Mar 16, 2014)

There are different rotation patterns for FWD and RWD. AWD's are based on FWD or RWD platforms and usually most of power still goes either to the front or rear. 











Feathering is caused by power application, toe, and braking. If everything's going right, power application is the primary cause of feathering and greater than the sum of that from toe and braking.. 













If feathering on a tire is severe, placing the tire in a position on the car that causes equally severe feathering in the opposite direction could cause the "tip of the feather" to tear off. So, the rotation patterns for FWD and RWD are different, with a severe-feathering position on the driven axle followed by mild-feathering (from braking and toe) in the opposite direction on the undriven axle. That gently wears off the tip of the feathers. The next position after that is back onto the driven axle, but in the opposite direction.


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## u.nanimous (Nov 1, 2014)

Wow I don't know how I missed added posts here the last 2 days but that's a ton reading.
Hope questions have been answered.


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## jaye944 (Jul 5, 2015)

again, I ask, is Bridgestone incorrect ?

1> Staggered - directional tires
2> Square set up - directional tires


*FOR HIGH PERFORMANCE AND DIRECTIONAL TIRES:
1. SIDE-TO-SIDE (FOR DIFFERENTLY-SIZED PERFORMANCE TIRES ON THE FRONT AND REAR AXLES)*
All tires are switched with their same-sized partner and remain on the same axle. The two rear tires switch to the opposite side with one another while the two front tires do the same.
*2. FRONT-TO-BACK (FOR DIRECTIONAL TIRES)*
All tires are moved from one axle to the other but remain on the same side of the vehicle. For example, the front left tire is moved to the left side of the rear axle while the rear left tire is repositioned on the left side of the front axle.


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## Autoputzer (Mar 16, 2014)

jaye944 said:


> again, I ask, is Bridgestone incorrect ?
> 
> 1> Staggered - directional tires
> 2> Square set up - directional tires
> ...


They are correct. Directional tires have to stay on the same side of the car, unless you want to remove and reinstall them on the wheels. Staggered tires have to stay on the same axle. *Those four/five-tire rotation patterns apply to non-directional tires and square set-ups. *That E46 M3 of mine had staggered, directional tires. So, I couldn't do any rotation.

I got the BMW itch really bad when I was invited to "an exclusive introduction" of the E36 M3 in 1994. It had non-directional tires with a square set-up. (The LCI is when they went to a staggered set-up.) That pre-LCI E36 M3 also had a full-size spare on a matching rim. So, it was a candidate for a five-tire rotation pattern, and it'd be possible to get ~50k miles out of the OE set of ~40k-mile tires.

For most BMW's now, if you have high-performance tires you also have a staggered set-up. Directional high-performance tires are out of vogue now. Most of them are now non-directional and asymmetric, with an OUTSIDE and an INSIDE sidewall. So, they can be rotated side-to-side. A lot of winter tires are still directional, though. 

I was in imminent danger of being laid off in 1994. So, no E36 M3 for me. But, my job was secure in 2000 when by mostly dumb luck I stumbled into the front of what would be the two-year long waiting list for an E46 M3. it took me 17 months to get the car. I kept it twelve years and 115k miles (burning through six rear tires and four front tires).

I learned the downside of changing just two tires at a time. Old tires don't work as well as new tires, even on try pavement were tread depth doesn't improve performance. When I had old tires at one end and new tires at the other end, I'd have massive oversteer or understeer at (and slightly beyond) the limit.


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## ard (Jul 1, 2009)

jaye944 said:


> again, I ask, is Bridgestone incorrect ?
> 
> 1> Staggered - directional tires
> 2> Square set up - directional tires
> ...


Are you quoting something from Bridgestone? Not clear…

Your posts tend to be incoherent and get twisted up by your lack of understanding, leading to a word salad…the use of dumb terminology, like “performance tires” in the bolded text above is pointless.


How about this: 

Do YOU have staggered tires NOW? Yes, No

Do YOIU Have ‘directional‘ tires NOW? Yes No

I will say that in your bolded #1 above, that CANNOT be done for directional tires. UNLESS you dismount the tire from the rim.

So… You can rotated directional tires, front to rear (etc) if you are square.

If you are staggered you can only rotate if you DISMOUNT the tire and remount. (Side to side, same axle)


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## jaye944 (Jul 5, 2015)

in post number 19

In replying to AP
*I was* quoting a bridgestone hyperlink *and said*
"This from bridgestone Tire Rotation: How and Why to Rotate Your Tires | Bridgestone Tires"

*I followed up by saying*
"I have *square setup with directional tires*, so rotation is Front-to-back / if I went staggered , side to side ? Most rotations are X-pattern for non-directional
Is Bridgestone wrong ?"

I then quoted bridgestone, the bold was from there website, taken from the hyperlink quoted above, I'm not sure what you mean by "dumb technology" this is bridgestone themselves nothing that I have said, I am dumb yes, Bridgestone are not.
*FOR HIGH PERFORMANCE AND DIRECTIONAL TIRES:
1. SIDE-TO-SIDE (FOR DIFFERENTLY-SIZED PERFORMANCE TIRES ON THE FRONT AND REAR AXLES)*
All tires are switched with their same-sized partner and remain on the same axle. The two rear tires switch to the opposite side with one another while the two front tires do the same.
*2. FRONT-TO-BACK (FOR DIRECTIONAL TIRES)*
All tires are moved from one axle to the other but remain on the same side of the vehicle. For example, the front left tire is moved to the left side of the rear axle while the rear left tire is repositioned on the left side of the front axle.

As already stated a few times, I have Square set-up, Directional tires, on AWD, I may go staggered.
option 1 as already said is for staggered setup, option 2 is for square set-up
You can't according to bridgestone do x rotate

AP was suggesting what I thought was right, wasn't correct, hence me re-confirming, which in post number 23, he confirmed

Option 1 & Option 2 "*are"* for directional tires they also make no mention of having to remount the tires, this is pretty important for them to leave that out I would have thought



ard said:


> Are you quoting something from Bridgestone? Not clear…
> 
> Your posts tend to be incoherent and get twisted up by your lack of understanding, leading to a word salad…the use of dumb terminology, like “performance tires” in the bolded text above is pointless.
> 
> ...


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## jaye944 (Jul 5, 2015)

anyway on that note have a great weekend guy's,

I think I have the answer I was looking for, both from my tire guy, bridgestone, from the discussion here and I will probably get one from my BMW dealer when I go there next

ciao


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## ard (Jul 1, 2009)

cclcal said:


> Changed tire to yokohama advan as+ which has 11/32in tread depth (no choice because i had to leave town same day), there is a 3mm tread difference (6mm diam) from other tires. Went to tire store to exchange tire for PS4S or PSS (out of stock) both have 9/32 tread depth. this will match my other tires much better which only have 7000 miles.
> Awaiting on tire store contacting Michelin for possible warranty or goodwill.


Wait. you are concerned about the TREAD DEPTH on two DIFFERENT brand/model tires?!!?

Tread depth is the least of your concerns....

A yokohama advan as+ in an XXX/YY-zz compared to a Michlin PS4S in the 'same' XXX/YY-ZZ may be off by 10mm.

You didnt give us your tire size- from tirerack I can look up the 'rolling dianeter' as well as the 'revs per mile'

Again, the tread depth ONLY matters when the tires were at day zero- perfectly matched.

Finally, your situation is THE reason to have a spare. So you dont waste $300+ on a tire that doenst mathc, becuase you need something. Next time you change tires, take the best one and toss it into the garage.


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## Autoputzer (Mar 16, 2014)

ard said:


> Wait. you are concerned about the TREAD DEPTH on two DIFFERENT brand/model tires?!!?
> 
> Tread depth is the least of your concerns....
> 
> ...


Wrong tire thread, Ard.


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## cclcal (May 9, 2006)

ard said:


> Wait. you are concerned about the TREAD DEPTH on two DIFFERENT brand/model tires?!!?
> 
> Tread depth is the least of your concerns....
> 
> ...


thanks

but all good now

returned yoko tire for full refund, got a PS4S for 50% off.
245/35/20 is the size

thanks


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## Boraxo (Sep 6, 2005)

I just went through this myself. I have 4 Michelins on my Mercedes GLS 450 AWD. A while back I got a non-repairable flat and Costco replaced the 2 rear tires (under warranty) with new Michelins so each axle would match (the old tires were discontinued 6 months after purchase so I could not replace only 1 tire). Rule #1 - Most shops will insist on matching tires for each axle.

Fast forward to last month, one of the older tires blows out and too little tread depth to repair. Thankfully it was one of the older tires. However following Rule #1 it would be impossible to replace only 1 tire as I would then have 3 different levels of tread. Rule #2 - be prepared to order your tires as I find tire stores rarely stock the Michelins or Pirellis or Continentals for premium vehicles (but of course they have plenty of deathstones and other lesser brands on hand).

Unfortunately I needed the SUV back in action quickly for a 500 mile trip starting later that day. So I made the mistake of ordering 2 Pirellis for same day delivery, rotated the Michelins (which had 50% tread left) to front and put the new Pirellis on the rear axle. HUGE MISTAKE. As I was warned, vehicles will often oversteer or understeer if you have different brands and different tread levels on front & rear axles. Both Mrs. B and I felt the handling was terrible particularly at high speeds and/or in the mountains. Rule #3 - NEVER put different brands on the same vehicle - and if at all possible try to match the tread style as close as possible, i.e. Pilot Sport 3 and Pilot Sport 4. This rule x2 on SUVs, AWDs, and performance vehicles like BMWs.

Thankfully this story had a somewhat happy ending - America's Tire agreed to replace the Pirellis (after 1000 miles no less) with matching Michelins and my SUV now handles as well as it did before.

So in sum:

(1) It is best to replace all 4 tires at the same time, but this does not make financial sense if you have a blowout and your remaining tires have good tread left.
(2) If you don't want to replace all 4, it is okay to replace 2 on the same axle, but this will mess up your rotation as you generally want to best tires on the rear axle.
(3) If possible rotate tires every year and consider annual alignments depending on mileage.
(4) Fix a flat warranties are not worth much (most shops will do this free or cheaply) and road hazard warranties are not worth much if you are in a rush or get a blowout far from your tire shop.

PS that rotation photo makes zero sense in this context - most BMWs (except mine) come with zero spare tires and runflats, or alternatively a donut spare (as is the case on my SUV).


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## Autoputzer (Mar 16, 2014)

Boraxo said:


> PS that rotation photo makes zero sense in this context - most BMWs (except mine) come with zero spare tires and runflats, or alternatively a donut spare (as is the case on my SUV).


Ignore the spare tire position, unless you have a full-size spare on a matching wheel. So, instead of a tire going to the spare tire position, it would go to the right-rear.

Both of our BMW's have square set-ups (all four tires and wheels are the same size). I measure the tread depths when I do a tire rotation. From that, I can calculate the wear in each channel on each tire, and the averages (channel, tire, axle, tire position, total). My BMW is a RWD 535i. Frau Putzer has an X3 xDrive 30i. Here are the wear totals by tire positions for the 535i''s OE tires (Goodyear LS2 run-flats), X3's OE tires (Bridgestone Dueler H/P Sport AS non-run-flats), and the second set of tires on my 535i (Michelin PSS high-performance non-run-flats), all for the first ~30k miles on each set of tires. The RWD 535i's rear tires wear about twice as fast as the front tires. AWD evens out tire wear. The X3's rear tires have only worn about 40% faster than the front ones.

















Notice that the right tires wear more than my left ones on my 535i. That's also the case in my Chevy Cobalt SS. That's because the roads here in Bubba County are flat and straight, and the only driving entertainment I get is taking left turns (larger diameter than right turns) faster than I'm supposed to.

With tread depth measurement and visual inspection of the edges of the tread during rotation, I can see alignment problems soon enough to have them corrected before the tires are severely damaged. I've also found that if I've hit a significant pothole, get an alignment. Potholes shouldn't be much of a problem in Danville, CA.

The big Range Rover still offers a full-size tire on a matching wheel as an option. Using that five-tire rotation, you can get 125% of the life out of a set of five tires (e.g. 75k miles out of a 60k-mile set of tires).


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