Front tyre wear, outside edge

[sweeper]

If we all check our rear tyres on our RWD Mercs they will be worn in the centres even with correct pressures.

Trust me, I've seen this.

Not on mine, they wear evenly across the back, and on the edges of the fronts, more so on the nearside. if you have very wide tyres and drive at high speed you can get more wear in the middle of the rears due to centrifugal force.

 

[c240yaz]

Its a hard subject, At the unloaded figure my fronts wear dead flat, the rears do eat the middle , by the time they are down to 4mm on the sides, they have 2½ in the middle, where do you trade off the fuel consumption verses ride and wear

Run with less pressure than the MB suggested in the rears

 

[stevesey]

Its a hard subject, At the unloaded figure my fronts wear dead flat, the rears do eat the middle , by the time they are down to 4mm on the sides, they have 2½ in the middle, where do you trade off the fuel consumption verses ride and wear

I often end up adjusting my tyre pressures to compensate/allow for uneven wear - fronts normally up a few psi to protect the edges (particularly the passenger front egde - which always seems to wear these days irrespective of the car), rears up or down according to how they have worn.

 

[c240yaz]

I often end up adjusting my tyre pressures to compensate/allow for uneven wear - fronts normally up a few psi to protect the edges (particularly the passenger front egde - which always seems to wear these days irrespective of the car), rears up or down according to how they have worn.

Me too. I have recently started over inflating my fronts, to put the load on the centre tread.

Note, if wearing on the passenger side only, N/S/F, suspect a worn ball joint, or a suspension bush worn on that side.

 

[television]

Me too. I have recently started over inflating my fronts, to put the load on the centre tread.

And I under inflate the rears on my only by a touch and got another 2k miles out of mine

 

[Rory]

And I under inflate the rears on my only by a touch and got another 2k miles out of mine

I do that too, although the centres are still wearing noticeably faster and I really only use the car for long, steady, motorway journeys.

There's supposed to be an old fashioned racing technique of chalking a line across the tyre and adjusting the pressures until the line wears away evenly. I keep meaning to try this, but never remember!

 

[television]

I do that too, although the centres are still wearing noticeably faster and I really only use the car for long, steady, motorway journeys.

There's supposed to be an old fashioned racing technique of chalking a line across the tyre and adjusting the pressures until the line wears away evenly. I keep meaning to try this, but never remember!

Yes I can recall when your car was brand new and your motorway runs. I do bring up this instability thing on the 203 and the camber angle and the way the tyres wear, I am curious as to why different angles have not been tried, as I do feel that if the tyres were sitting flatter then the driving could be improved. The 203 is the main car where everyone complains of the high speed instability. Perhaps the static measurements change when driven. we have had people change the rear suspension bushes and more. The best answer at the end of the day was to reduce the tyre pressures slightly to stop the car from changing course at speed.

The 124 never behaved like it, nor the 129 and 230 nothing changes on these cars at any speed.

 

[whitenemesis]

I was told by a tyre technician that swapping wheels diagonally or side to side initially increaces wear as the tread will have feathered very slightly.
What can be more problematical is that the belts may shift and cause instability at speed, sometime mistaken as imbalance (which I suppose it is but can't be corrected by weights).
I have never diagonally rotated wheels on my cars.

With my current car tyre wear is very even across the rears and only marginally wear on the edges of the fronts. Front and rears tend to need replacing at the same time for me once a year (xmas ) at ~ 22k miles

 

[Rory]

I was told by a tyre technician that swapping wheels diagonally or side to side initially increaces wear as the tread will have feathered very slightly.
What can be more problematical is that the belts may shift and cause instability at speed, sometime mistaken as imbalance (which I suppose it is but can't be corrected by weights).
I have never diagonally rotated wheels on my cars.

With my current car tyre wear is very even across the rears and only marginally wear on the edges of the fronts. Front and rears tend to need replacing at the same time for me once a year (xmas ) at ~ 22k miles

Just back from holiday in the US and I noticed that, along with 3000 mile oil changes, tire rotation service is heavily advertised by their fast fit type places. Alignment checking also seems to be a more routine service item than it is here.

Interesting that your tyres wear evenly all round. I changed the original rear Bridgestone Turanza's at about 20K miles and I really left that a bit late. Yet the fronts at 35K still have 3-4mm in the centres but will need changing soon as the edges are worn away.

 

[Dieselman]

I was told by a tyre technician that swapping wheels diagonally or side to side initially increaces wear as the tread will have feathered very slightly.

Interesting point, that.

I've just read my E class booklet and MB say don't reverse the tyre rotation direction.

I've never heard that before and many manufacturers say to use all five wheels so the direction must reverse.

Appologies to kth286.

As per Merc's recommendation you should put front to back ON SAME SIDE OF CAR, so rotational issue does not arise.

I have not seen anywhere that Mercedes says swop diagionally - so DO NOT.

.

 

[merc07]

Well, I bought a gauge and measured them properly. Fronts are both 5mm inside and centre and outside are 2mm passenger and 2.5mm drivers - Thats not right on the edge though. Rears are 3mm centre and 4 on the outsides - 18500 miles. This seems about normal from everyones feedback, although it still feels like the fronts have been wasted with all that good tread left. Might even beat the 22k of Whitenemesis !

 

[Dieselman]

Remember you don't need to have any visible tread at the edges for an MOT pass now.

 

[stevesey]

Me too. I have recently started over inflating my fronts, to put the load on the centre tread.

Note, if wearing on the passenger side only, N/S/F, suspect a worn ball joint, or a suspension bush worn on that side.

All my cars do it - have always put it down to preserving momentum through roundabouts

 

[Dieselman]

All my cars do it - have always put it down to preserving momentum through roundabouts

Apparently Mercedes cars overcome the laws of physics.

On a Merc the fronts will not.

This is due to the normally high castor angle built into the Merc front geometry - traditionally about twice the castor angle of other cars.

This means the front wheels lean over a lot on turns. You will see this when looking at your turned front wheels when parking your car for instance.

So, on roundabouts the outer wheel will lean inwards and the inner wheel will lean outwards.

So, the tread on the outer wheel is wearing on the inner side, and the tread on the inner wheel is wearing on the outer side as you travel around about.

Perhaps you need to draw it on a piec of paper to best visualize the situation.

 

[stevesey]

Hmm - that assumes no body roll and rock solid sidewalls.

 

[merc07]

The edge wears due to the weight of the car forcing the tyre to roll under.

Would the same tyres only with a higher load rating help. These would have a stiffer side wall construction.

Me too. I have recently started over inflating my fronts, to put the load on the centre tread.

How much is extra ? A couple of pouds? Maybe then fronts +2, rears -2.

 

[merc07]

Going back to Philayl's post with the link to http://www.wheels-inmotion.co.uk/

Some interesting reading on there - under camber angle basics

Quote....

Another common reason for camber wear is changing from standard tyres and wheels, to a larger diameter rim and a smaller profile tyre, the geometry is based on the dynamic range of the suspension, and the on/off camber tolerances are calculated for a known tyre width, the wider tyre will move the weight distribution nearer to the (on,) or (loaded) state, so it can be seen that the active camber will be out of tolerance, and is now considered normal.
The intention to change to bigger, wider wheels and tyres must be approached with caution, the wheels camber must be re-set nearer to the off or (unloaded) setting, accommodating for the extra tyre width.


Are there different camber settings for a W203 with sports package and 17" 225/45 & 245/35 tyres against the standard 16" 205/55 ? - Probably not !

Adam

 

[Rory]

Would the same tyres only with a higher load rating help. These would have a stiffer side wall construction.

The ride would suffer. And anway, the Bridgestone's that were on my car from new are noted for stiff sidewalls (the car felt like it was on iron rings, not rubber tyres) and I've still suffered the excess wear on the edges.

How much is extra ? A couple of pouds? Maybe then fronts +2, rears -2.

I recently changed to run mine at +3 on the front and -3 on the back - so basically reversing the minimum pressure settings of 30F and 33R.
I guess in reality 2 or 3lbs is neither here nor there - many garage gauges wouldn't be that accurate anyway. I use a dial gauge which I've compared to several other sources and believe it to be accurate (but can't be certain).

The replacement Michelin Primacy HP's on the back are still wearing slightly more in the centre's but nothing like as bad as the Bridgestone's did.
Can't really tell on the fronts as they're still the originals but I'm hoping to wring some more time out of them before the edges wear away completely.

 

[television]

Going back to Philayl's post with the link to http://www.wheels-inmotion.co.uk/

Some interesting reading on there - under camber angle basics

Quote....

Another common reason for camber wear is changing from standard tyres and wheels, to a larger diameter rim and a smaller profile tyre, the geometry is based on the dynamic range of the suspension, and the on/off camber tolerances are calculated for a known tyre width, the wider tyre will move the weight distribution nearer to the (on,) or (loaded) state, so it can be seen that the active camber will be out of tolerance, and is now considered normal.
The intention to change to bigger, wider wheels and tyres must be approached with caution, the wheels camber must be re-set nearer to the off or (unloaded) setting, accommodating for the extra tyre width.


Are there different camber settings for a W203 with sports package and 17" 225/45 & 245/35 tyres against the standard 16" 205/55 ? - Probably not !

Adam

Thanks Adam and that answers what I asked twice, I have never seen different camber details for different wheels, but I will make a point of looking.

As For Rory getting 35k out of a set of tyres , I dont think that I have ever owned on that has got past 20k

 

[Dieselman]

Thanks Adam and that answers what I asked twice, I have never seen different camber details for different wheels, but I will make a point of looking.

As For Rory getting 35k out of a set of tyres , I dont think that I have ever owned on that has got past 20k

Not for different wheels but for different springs there are.

I suspect my current Michelins will get over 30k, no problem.