[Bianchi Dave]

Quick query tor those running X drive. Obviously the S drive cars have a higher wear rate on the rear tyres, but does this hold true for X drive cars? Does the rear bias mean the rears still wear quicker, or does the x drive even things up?

[JNW1]

Originally Posted by Bianchi Dave

Quick query tor those running X drive. Obviously the S drive cars have a higher wear rate on the rear tyres, but does this hold true for X drive cars? Does the rear bias mean the rears still wear quicker, or does the x drive even things up?

X-drive evens things up in my experience; wear across all four wheels with my F31 335d was very similar and the same seems to apply to my G21 M340i as well.

Having said that I've also seen some X-drive owners say the rears on their cars have worn much quicker than the fronts so I suspect driving style also has something to do with it?

[HighlandPete]

Originally Posted by Bianchi Dave

Quick query tor those running X drive. Obviously the S drive cars have a higher wear rate on the rear tyres, but does this hold true for X drive cars? Does the rear bias mean the rears still wear quicker, or does the x drive even things up?

So many variables.

Depends on the model and how BMW have set up the xDrive hardware and software. Whether the older models with more a 60:40 ratio, or through to the later M Performance models with more an initial 100:0 ratio, using RWD much more, until xDrive is required. Then there is the "efficiency mode" in later models which again uses RWD, until more traction is required. Even the driving mode, can change the traction bias in some models. Tor example Sport and Sport + will give more of a RWD bias.

Driving conditions influences the wear rates. Motorway, vs. more of the twisty stuff and/or a lot of stop-start type driving. all influence the wear rates, plus the driver... lots of harder accelerations, will have some impact.

Then there's the tyres themselves. Some staggered setups will have the wider tyres with softer compounds to give better grip. Wear rates can be faster, on that factor alone.

[HighlandPete]

A couple more factors.

Alignment and geometry, this may influence wear. It's the toe settings, front and rear that have a big influence. Driving conditions and xDrive demands will again influence the wear rates.

Closely matching RC front and rear helps balance wear rates. The bigger the mismatch the greater the "micro scuffing" of the tyres. The mismatch has to be absorbed somewhere, either to the transfer box, (particularly to older transfer box designs) as heat and/or wear, or as added tyre wear.

[JNW1]

Originally Posted by HighlandPete

So many variables.

Depends on the model and how BMW have set up the xDrive hardware and software. Whether the older models with more a 60:40 ratio, or through to the later M Performance models with more an initial 100:0 ratio, using RWD much more, until xDrive is required. Then there is the "efficiency mode" in later models which again uses RWD, until more traction is required. Even the driving mode, can change the traction bias in some models. Tor example Sport and Sport + will give more of a RWD bias.

Driving conditions influences the wear rates. Motorway, vs. more of the twisty stuff and/or a lot of stop-start type driving. all influence the wear rates, plus the driver... lots of harder accelerations, will have some impact.

Then there's the tyres themselves. Some staggered setups will have the wider tyres with softer compounds to give better grip. Wear rates can be faster, on that factor alone.

Yes, difficult to draw conclusions from what various owners are saying when how and where they drive are likely to be very different. However, I don't think either my driving style or mileage profile have changed significantly since moving from S-drive to X-drive and in my experience tyre wear is much more even with the latter.

[HighlandPete]

Originally Posted by JNW1

Yes, difficult to draw conclusions from what various owners are saying when how and where they drive are likely to be very different. However, I don't think either my driving style or mileage profile have changed significantly since moving from S-drive to X-drive and in my experience tyre wear is much more even with the latter.

I feel the same, difficult to draw any specific conclusions. I often wonder what my experience would be like, knowing my RWD experience is rear tyres can wear virtually twice as fast as the front.

When my son was running his X3's, they would wear the rear faster than the front. Even with the typical 60:40 ratio.

[Bianchi Dave]

Thanks guys, that's helpful. It's in relation to a year old M340i so will have a performance orientated set up.

I was curious as I'll be fitting a square winter set up soon. With my old F31 (s drive) I always put the tyres with the deeper remaining tread on the rear, so I'll continue to do the same on the M340i.

Cheers

[HighlandPete]

Originally Posted by Bianchi Dave

Thanks guys, that's helpful. It's in relation to a year old M340i so will have a performance orientated set up.

I was curious as I'll be fitting a square winter set up soon. With my old F31 (s drive) I always put the tyres with the deeper remaining tread on the rear, so I'll continue to do the same on the M340i.

With the M340i running the RWD bias, I'd be doing the same. Deepest rear tread for both traction and the safety bias.

[Bianchi Dave]

Originally Posted by HighlandPete

With the M340i running the RWD bias, I'd be doing the same. Deepest rear tread for both traction and the safety bias.

Exactly Pete Just need to buy new winter wheels.

[johnung]

Originally Posted by Bianchi Dave

Quick query tor those running X drive. Obviously the S drive cars have a higher wear rate on the rear tyres, but does this hold true for X drive cars? Does the rear bias mean the rears still wear quicker, or does the x drive even things up?

There are so many factors that go into tire wear as you can see from the responses. But there are only a few things under driver control.

1) Keep them properly inflated.
2) Rotate them in a timely manner if you chose a set up that is rotatable.
3) Get an alignment regularly or when you see unusual tire wear.

I would never buy a European Sports Sedan and then put high mileage tires on it. That would be sacrilegious.

An F30 XDrive that's properly aligned is going to wear the outsides of the front treads and the insides of the rear treads. That's one reason that I am a proponent of Square setups. Front to rear tire rotation keeps them wearing and performing perfectly throughout their useful lifespan.

Someone mentioned the rears wearing more than the fronts. A reason that many forget is the electronic system designed to maintain control. It can automatically independently brake the rear wheels. So if a car is doing a lot of spirited driving it can also be wearing rear tires and rear brake pads more without the driver realizing.

[Lorcan]

Originally Posted by johnung

Someone mentioned the rears wearing more than the fronts. A reason that many forget is the electronic system designed to maintain control. It can automatically independently brake the rear wheels. So if a car is doing a lot of spirited driving it can also be wearing rear tires and rear brake pads more without the driver realizing.

We've seen this on track days when drivers are unaware DSC is being activated.

[Ennoch]

It's very much down to the driver. My 335xD F31 still had the original 225/255 19" Bridgestone S001's on the rear when I got it with about 3.5mm left, but worn inner edges - that was at 32k. I got another 5k before they got ditched and would have probably done 45k if I'd let them run to the wear markers. The fronts however got changed at 25k miles. So the original owner wore out the fronts 50% faster than the rears.

In contrast I have run it with Pirelli Sottozero 3 RFT winters and Michelin PS4S summers. The front Pirellis are at 6mm and the rears are at 4mm (a bit low for winters really) but with completely even tread wear across the width of the casing. The Michelins are at 4.7mm front and 3mm rear (7.2mm new) after about 8k miles. Again, perfectly even wear across the casings using 2.7 bar front and 2.6-2.7 bar on the rear. So for me I'm wearing the tyres out 50% faster on the rear.

My experience of BMW's is that for the average driver the cars have too much camber at the rear and not enough at the front. However, if you know how to drive and set the car up to rotate in corners then you get even wear. This is opposed to the average driver turning more and more to get it to turn, chewing the outer edges of the front tyres through overloading, and scrubbing the rears as they aren't transferring the weight onto the outer shoulder.

What does all this say? Bumble and you will get worn inner rear edges and outer fronts, and will likely go through fronts faster than the rears. Drive harder (and better) and you will get even wear as the geometry will be working with you rather than against you, but at the expense of wearing the rear tyres out more quickly, especially if you're coming out of corners hard on the throttle and with the rear tyres taking a lot of load. But then you don't buy a quick car to bumble, but I am pretty lucky with the roads I get to drive on and the times I do so which allows me to have a lot more fun than if you do most of your driving on motorways or in the suburbs with heavy traffic.

[SantaEugence]

Mapped 330dx had a few sets of MPS4S on staggered 19”. All times worn pretty consistently front and back. In fact last time the rears were on about 4.5 and the fronts on 4 when they were replaced

[JNW1]

By way of an update out of idle curiosity I've just checked the remaining tread depths on my G21 M340i; it's still on the original Pirelli run-flats and at just over 15k miles there's 5mm of tread remaining on all four tyres (I know, I'm obviously not trying hard enough! ).

Obviously what I see in terms of rate of wear won't necessarily be representative for others but driven the same way I always went through rears faster than fronts on the various RWD BMW's I've had. Therefore, for me at least X-drive has definitely resulted in much more even tyre wear front to rear...

[Elijah Hua]

For my f30 340i xdrive, the front wear much quicker that the rear. the 225 tire is just not enough to deal with aggresive driving style.

[Ennoch]

Originally Posted by Elijah Hua

For my f30 340i xdrive, the front wear much quicker that the rear. the 225 tire is just not enough to deal with aggresive driving style.

It's not an 'aggressive' driving style that does that but a crap one which doesn't use weight transfer to get the car turned in and that blends with the overly-nannying traction control which causes the car to push on more. Use the gears and sport+ when pushing on and even with 225 fronts, which I am no fan of (I prefer square 245), you can completely dial out the understeer to the point the back end is properly rotating. With the stock staggered 19" setup I wear the rears about 40% faster than the fronts in both winter and summer flavour FWIW. Honestly, learn how to rotate the car properly and you'll sort the excessive front tyre wear.

[fuzzybunny]

All the tyres on my x-drive had worn down to the same amount (around 3mm) prior to replacement. The front slightly more than the rear. An expensive replacement for all four corners!

[Alscoob]

Old thread resurrection but... The rears on my 540i touring x-drive are wearing quicker than the fronts but nowhere as quick as the 'S' drive variants (used to do 2 sets of rears to 1 front), but then, there are many occasions that I 'drive' it on some good B roads

In saying that the car was on 10k miles when I bought it and at that time the tread front to rear was even, so as mentioned elsewhere, just depends on how you drive I guess.

[TurboWeasel]

The rears last longer than the fronts on my RWD 330d. As mentioned above, it's all down to the driver and the car's use

I never, ever wheel spin or drift it because it's just pointless and chavvy. Spinning isn't winning. Pretty much gentle acceleration everywhere except for very occasional squirts, so the rears get an easy life in my custody And at £250+ per rear staggered, it's for good reason!

[Alscoob]

Originally Posted by TurboWeasel

The rears last longer than the fronts on my RWD 330d. As mentioned above, it's all down to the driver and the car's use

I never, ever wheel spin or drift it because it's just pointless and chavvy. Spinning isn't winning. Pretty much gentle acceleration everywhere except for very occasional squirts, so the rears get an easy life in my custody And at £250+ per rear staggered, it's for good reason!

Interesting, I've never had a car where the driven axle tyres have lasted longer than those at the other end. IMO no matter how gentle you are in puling away the driven tyres are doing the work the opposites are just like trailer wheels either being pushed or pulled along. Okay they steer and brake so have resistance and abrasion through the tarmac contact but, that's generally no where near as much as the acceleration forces pushing the whole weight of the car along.

Okay agreed you can prolong the life of the rears by being careful but to wear the fronts out first on a RWD car if everything else is in alignment you must brake exceptionally hard and / or steer ferociously.

[TurboWeasel]

Originally Posted by Alscoob

Interesting, I've never had a car where the driven axle tyres have lasted longer than those at the other end. IMO no matter how gentle you are in puling away the driven tyres are doing the work the opposites are just like trailer wheels either being pushed or pulled along. Okay they steer and brake so have resistance and abrasion through the tarmac contact but, that's generally no where near as much as the acceleration forces pushing the whole weight of the car along.

Okay agreed you can prolong the life of the rears by being careful but to wear the fronts out first on a RWD car if everything else is in alignment you must brake exceptionally hard and / or steer ferociously.

I agree with you but it's just what I've observed on my car. As per my Pilot Sport 4 ZP thread, the old Bridgestone SOO1s that came off were 3mm remaining at the back and 2mm remaining at the front. There are no alignment issues with the car.

Perhaps I made it sound more like the fronts were practically bald and the rears only half worn

I shall keep an eye on the fresh set of 4ZPs and see how they wear down, but I do indeed brake hard and late, and turn in quite aggressively as well, so maybe it's just my driving.

Agreed on the driven wheels usually wearing faster but unless the tyres are actually spinning or sliding, there should be no accelerated abrasion wear. Peak adhesion with both traction and braking is just on the edge of slip, and is where tyre wear is the highest (apart from spinning/sliding). That kind of tyre load is more common with hard braking on the road, hence why my fronts wear out faster

Track days and 1/4 miles etc, yeah, lots more abrasion on the rear tyres.