Zero’s comment in the i10 thread has prompted this where he says his rears have already been changed.
I have pretty much my whole driving history had front wheel drive cars. And front tyres always wear out quicker than back. In one car I had 3 changes to the front whilst still the original set on the rear.
It’s obvious that driven wheels is the factor but from a physics/ simple explanation for me, when 4 tyres are going in a straight line, why is there heavier load on the ones that are being driven?
I get if you were constantly doing wheel spinning or scrabbling for grip you are going to get scrubbing of the tyre. I would have thought more wear would be attributable to the front steering tyres as they would often be changing direction and therefore more friction involved? And with most cars having engine at front, the weight on the front tyres is greater?
Why is the drive of the vehicle such a deciding factor?
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I guess someone could explain it more scientifically, but my feeling is that on a RWD vehicle the front tyres are just doing less work. They only have to steer and brake while the back ones do the pushing.
On my RWD car I get about 40k miles from back tyres and about 50k from front ones. Lots of motorway miles involved of course to get that.
Tangentially, and perhaps trivially, but certainly noticeably, winter tyres seem much more resistant to pothole damage than summer grade ones.
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>> Why is the drive of the vehicle such a deciding factor?
Add this to the mix, mine is AWD (albeit with a RWD bias).
70k miles - Its on its third set of rears, second set of fronts. Original brake pads & disks on the front, 2nd set pads and skimmed disks on the rear.
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>> Original brake pads & disks on the front, 2nd set pads and skimmed disks on the rear.
I find that strange, as even with 4WD, I'd have thought the fronts were doing most of the braking, unless it's something to do with all the mass of the drivetrain. Those rear discs must've had some meat from new as the norm nowadays is for the discs to wear almost as much as the pads, unless they needed skimming due to corrosion? Didn't know you could still get discs skimmed.
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My car had its first set of replacement front pads and discs at 96k, the rears lasted until 180k. At that point, both front and rear brakes were replaced.
Mercedes parts and the tyres to fit it are quite expensive I suppose, but they do seem to last well, so maybe they are not really.
No other items have given any problems yet so suspension/gearbox etc seems pretty robust.
It could be argued that it was just luck, but my previous near identical model also went to 200k with similar brake/tyre usage and no non service item repairs.
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>> for the discs to wear almost as much as the pads, unless they needed skimming
>> due to corrosion? Didn't know you could still get discs skimmed.
Main dealers wont skim disks, specialists will and do, where the minimum disk thickness is still specified by the manufacturer.
I insist on BMW OEM brake parts, your factors parts (pagid etc) simply dont last.
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I have no clue about the physics involved, but I wonder if regular towing has had an effect on your brake wear Z?
As BT mentions, it seems at least unusual to wear rears so quickly.
Not that it matters provided everything continues to work as it should.
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...there are some theories that EPB 9with auto-apply/release) can have some effect on rear discs, along with (adaptive) cruise control and/or automatic speed limiter (not that Z will use the latter ;-) )
More brake application than your average "non-smart" car.
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Our 2013 'lingo wears rears before fronts. Towing may be a factor but the fast fit in Newcastle u Lyme that changed the rears when we were caught out by how badly worn they were* said all Mk3 versions do that to some extent.
Currently on 4th rears and third fronts at 125k. Rears will need changing again before long. Worst at the outer edges - again they all do that apparently.
*Lesson learned about checking all four tyres properly and not just glancing at the rears.
Brakes on pads #3 discs #2 ant the front. Rear pads/discs had to be replaced out of course due to a stuck caliper.
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>> I have no clue about the physics involved, but I wonder if regular towing has
>> had an effect on your brake wear Z?
Undoubtedly towing has an effect on tyre and brake wear on the rear, but only tow about 2k miles a year max. Lumping 60kilos of dogs and cage around in the back probably also has an effect.
Think T&E touched on it also that stability control (ie braking individual wheels) probably contributes to this.
Based on my gazzilion miles of driving history, my brake and tyre wear on the beemer is not what I would call excessive, just that it all seems to have shifted from front to back.
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Zero, do you know the make of the OEM?
My car is telling me front pads due in 1000 miles. Now I will obviously physically check that this is true and not just idrive making things up, but would like to know what the OEM brand is?
Car has done 41k miles and this will be first pads change.
Got a nice drive to Cornwall lined up in May for a wedding so depending on condition of them, may get them changed before.
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If your typical usage involves a fair bit of stop/start traffic then your brakes will wear more quickly Bobby.
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Yeah my commuting days are long gone.
Most of my journeys are local ish. So stop start traffic.
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I drive does not make things up, but the warning is fairly generous. I did 2k miles from 1k warning (ie got an extra 1k miles) before they were changed, and no damage was done (I kept a visual check on them)
As for OEM, Pads, primarily Brembo or Delphi, Disks - primarily Brembo. Avoid Pagid.
Last edited by: Zero on Tue 11 Apr 23 at 11:32
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I expect I've mentioned before but the rear discs and pads on my previous PHEV (Ampera) needed changing at (I think) around 50k. They were hardly worn but had seized (or similar) due to lack of use - with KERS assisting much of the braking they don't get used very often.
There is a trick, which is to put the car in neutral while at speed, then slow using the brakes (doesn't have to be harsh braking), ideally down a hill like a long off-ramp.
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Since 1998 I have rotated the wheels on all my cars following manufactures guidelines. I much prefer to change all my tyres at the same time. Plus, when I have the wheels off, I can thoroughly inspect and clean the alloys and tyres.
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>> re tyre rotation
I went to do this and found out that because the car has tyre pressure sensors, simply moving wheels from front to back isn't an option because it mucks up the display of what's what.
You could of course take the covers off and move them front to back but then one would have to rebalance the whole lot.
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Tyre wear is also dependent on toe and camber settings.
With the steering straight ahead the tyres will not be vertical to the road surface neither will they be parallel to the direction of travel.
I bought an ex-demo Porsche from AFN that chewed front tyres because they'd setup the frontend to be sharper than factory settings. It also had asymetric, directional tyres, different sizes front and back.
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Car4play, you sure about that?
My car has tyre sensors and I rotate front to back every season and then just reset my TPMS.
Pretty sure someone explained to me before that these send a signal to a sensor in each wing or something so that car knows which one is which.
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I thought that too Bobby but someone on the MG forum was asking about rotating wheels and was told you couldn't for the above reason. My recollection was that my previous car would sort itself out. So maybe it's car dependent.
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Systems and implementation of sensors vary
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>> Systems and implementation of sensors vary
When the requirement for tyre pressure sensors was new there seemed to be several solutions, including some using wifi and the actual pressure on in the tyre.
In my Skoda (no such system in the 'lingo) it uses the ABS system and will sound an alarm if one wheel's rotation speed is out of kilter with the others. Only had it go off once, on the A9 last year somewhere near Aviemore. Stopped, checked the pressures and re-set it. Not a beep since.
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>> when 4 tyres are going in a straight line, why is there heavier load on the ones that are being driven?
Because they are being used to pull the weight of the car forward against resistance from inclines, the rear tyres and the airflow over the car. Simply accelerating and maintaining speed wears your tyres, in the same way that the soles of your shoes would wear from the action of pushing a scooter forward. Or indeed from pushing you forward as you walk.
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>> In one car I had 3 changes to the front whilst still the original set on the rear.
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Can of worms but you're supposed to put the new ones on the back and the old rear tyres on the front. Apart from anything else, it avoids the rears from getting too old.
Not all cars wear their tyres unevenly - we've a Jazz and a Tiguan that both wear pretty evenly all round. The Tiguan is 4Motion but only when the fronts lose traction.
The RWD Merc I had used to eat rear tyres though, and that was just on steady motorway cruising. 20K from a set, typically. I changed the fronts at 40K but they still had loads of tread left but had scrubbed the edges - common on Mercs.
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Can’t switch them front to back in my car as they are different sizes.
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>> Can’t switch them front to back in my car as they are different sizes.
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Jacked up rear and sidewinder exhaust?
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Nice idea, but more conservatively perhaps, 265s on the rear and 245s on the front.
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Thanks Kevin, but that’s way too near the equator for me now the sun is so high in the sky!
;-)
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Tyre wear - Runfer D'Hills
