Tyre Rotation

[television]

Apolgies if I'm stating the obvious here but my car (and I think some other Mercedes models) has different size tyres front and rear.

When you have different size wheels back and front ,then you do not change the wheels around and leave as they are

 

[Blobcat]

So what do you all do in practise? If non-directional tyres - Diagonal swap or same side swap?
How often to swap - every 10K or 15K miles or dependent upon wear?

Number cruncher mentions MB's recommendations - what do they recommend exactly?

I swop my same side, the new tyres go on the back and I put the part worn rears onto the front. I had a camber issue so my fronts wore out 10K before the rears so I only have to change a pair at a time and am getting >30K miles from a set.

(Mine are same size all round)

 

[S80]

One disadvantage of 'rotating' tyres to even out wear is that you can end up needing to replace four of them in one go.

Not too bad for my W124 with its skinny 195/65 R 15s, but could be a shock to the wallet with some meatier sizes

 

[antijam]

One disadvantage of 'rotating' tyres to even out wear is that you can end up needing to replace four of them in one go.

Not too bad for my W124 with its skinny 195/65 R 15s, but could be a shock to the wallet with some meatier sizes

Mind you, not doing it can somtimes land you in the same situation. The front tyres on my heavy Espace have almost exactly half the life of the rears. (fronts have to cope with both drive and steering - rears are just along for the ride). Just had to give the wallet a blood-letting and replace all four as the wear-out coincided again.

 

[S80]

Just had to give the wallet a blood-letting.....

Yes, I know what you mean

It seems as though no matter how hard you research a tyre purchase, you somehow feel 'fleeced' when you've had them fitted! Personally, I hate tyre-buying time

Nothing seems as hard to pin down as the 'real' price of a tyre:razz:

 

[Number_Cruncher]

>>We have always had something like 72% of the braking energy going to the front wheels

That depends on the fore and aft position of the centre of gravity relative to the car's wheels, and also the height of the centre of gravity. Every car is different.

Original Minis, for example, were both front heavy and short wheelbase, and they had virtually no braking force on the rear axle. As you might imagine, once you have a car with front weight bias, and forward weight transfer under braking, there's very little load on the rear axle any more!

The British Construction and Use regulations are quite relaxed about this, simply stating that rear lock up should be avoided. The more stringent ECE regulations demand that not only should rear lockup be avoided*, but that the braking force on the rear axle should make good use of the available vertical load there, so-called "adhesion utilisation"

* There are some limited regions of deceleration where the curves for adhesion utilisation for the front and rear axles are allowed to cross.

 

[rf065]

Apolgies if I'm stating the obvious here but my car (and I think some other Mercedes models) has different size tyres front and rear.

Mine too, so I cannot swap tyres. Just have to replace them when worn which also means the best ones cannot always be on the rear either.

Russ

 

[television]

The rate at which my 230 can eat rear tyres does not give them a chance to get old,,so nearly all the time I have the best ones on the rear

 

[Alex M Grieve]

The rate at which my 230 can eat rear tyres does not give them a chance to get old,,so nearly all the time I have the best ones on the rear

Hooligan ......... !

 

[television]

Hooligan ......... !

Alex,,I am not one of those, my rear disc are still original at 42k miles

 

[Alex M Grieve]

Alex,,I am not one of those, my rear disc are still original at 42k miles

And I thought I was the only one who never slowed down.

I take it all back!

 

[television]

And I thought I was the only one who never slowed down.

I take it all back!

Thank you

 

[haggettd]

The main reason for changing them is to balance out any wear that has taken place over the surface of the tyre. On the fronts often the tyre will wear more on the inside than the outside, by putting this on the rear,it helps to balance out this wear.

When you have directional tyres and wider ones on the rear and your fronts tend to wear on the insides first as television suggests all is not lost!

Have a tyre fitter swap the fronts over. The tyres have to come off the rim of course.
So, the inside of the lh tyre which is worn then becomes the outside of the rh tyre. Directional running is maintained and you'll get more life.

Swap em over when you've done about 10-15k miles depending how your car wears them and you'll get the max mileage.

If your tyres are £120 each and usually last 18000 miles that comes to 1.333 pence per mile.

If you swap them around and get 25000miles that comes to 0.96 pence per mile.

So, to cover 25k miles on a set of tyres will cost £240.
To cover the same distance at 1.333 pence per mile would cost £333.33!

If your tyre swap costs £20 you'd still be £73 better off:smile:

I other words, if the swap cost £20 you'd only have to get an extra 1500 miles out of them to break even!

PS I always used to put my best tyres on the front of my last car (Skoda Octavia 2.0TDi).
A good front tyre in the wet will disperse water effectively and will resist aquaplaning. The more worn rear won't aquaplane either cos the front's cut through the puddle.
I've had worn tyres on the front and they aquaplane all over the place on a wet drive!

The car would only ever lift off oversteer on a wet corner and it would do it only reluctantly and controllably.

It would do this on 4 brand new tyres as well btw.

In the dry there was never any danger of anything other than understeer - that's how most cars are set up anyway.

Who's saying that a legal but worn tyre offers insufficient grip compared to a fresh tyre anyway? Is it not the same rubber compound all the way through?

 

[television]

In my case the wear across the width of the tyre is not too bad,,but the tyres on mine do cost some £250 each,, I keep an eye on them after some 8k miles, and would swap them over if the wear was significant,I adjust the presures for the center to outer edge wear.

 

[rf065]

PS I always used to put my best tyres on the front of my last car (Skoda Octavia 2.0TDi).
A good front tyre in the wet will disperse water effectively and will resist aquaplaning. The more worn rear won't aquaplane either cos the front's cut through the puddle.
I've had worn tyres on the front and they aquaplane all over the place on a wet drive!


Who's saying that a legal but worn tyre offers insufficient grip compared to a fresh tyre anyway? Is it not the same rubber compound all the way through?

Your argument starts to fall down on cornering as the rear wheels do not follow the fronts. If you corner on a snow covered road you will see four seperate tyre tracks until the car is on a straight line again.

And, some tyres do a different compounds as they wear down too, apart from that everyone knows a worn tyre has less grip than a good one, especially if it does not have enough tread to disperse water.

(ignore Malcolms name on the quote, it is from the post above his?)

Russ

 

[television]

(ignore Malcolms name on the quote, it is from the post above his?)

Russ

Thank goodness for that I just had to put another battery in my pacemaker

 

[Alex M Grieve]

Thank goodness for that I just had to put another battery in my pacemaker

I thought you were going to have it "mapped"?

 

[television]

I thought you were going to have it "mapped"?

I was thinking about it,, MPG "man power go" but I do not need that so much these days

 

[hawk20]

I think it was AutoExpress who reported an interesting test showing that cars with 3mm of tread on the tyres could stop, in the wet, in 60% of the distance taken by those with the legal minimum of 1.6mm. Some say change early rather wait till the last minute, but they are a costly item.

I haven't rotated mine and they are directional. They have done 21,500 miles so far and to my surprise have worn evenly on the E estate.

On the S class the rears wore out quickly!

 

[haggettd]

Your argument starts to fall down on cornering as the rear wheels do not follow the fronts. If you corner on a snow covered road you will see four seperate tyre tracks until the car is on a straight line again.

I was referring to travelling at speed on a sopping wet road in the rain. Aquaplaning will occur around 50-60mph in puddles with good tyres and a lot less with baldies.
I'm sure if you've had that experience on a m'way where you hit the 'river crossing' at 60 and you lose all steering control and your front wheels spin you'll wish you had your better tyres on the front.

In the snow, if you prefer to understeer straight on into a kerb or ditch on your worn front tyres go right ahead.

I much prefer to have the front go where I want it to and let the tail do what it wants. Nothing happens fast in the snow anyway and it's easy to control with a little practice.
100% of rally drivers can't be wrong about the best way to get round a skiddy bend! - half sideways!

Go practice on a snowy car park or grassy field. Turn your ESP off and find out what your car really does. Not enough people do and rely on the electronics alone. (ABS on snow or gravel = nightmare)
You WILL have a time where you've got good fronts and worn rears if you can't swap em over and aren't a millionaire, so you'd better know what your car does.


I would

And, some tyres do a different compounds as they wear down too, apart from that everyone knows a worn tyre has less grip than a good one, especially if it does not have enough tread to disperse water.

All tyres use different materials in their construction but I've never heard of less grippy rubber being used when you're within 3mm of the bottom of the grooves.
It's horses for courses with tyres and compromise city.
In the dry a 1/2 to 3/4 worn well scrubbed tyre wil give the best grip as there's less rubber to squidge around.
In the wet you need adequate water dispersion to prevent aquaplaning. In mud and snow you ideally need narrow tyres with deep tread.
It is simply not true that a new tyre will grip better than a worn one just because it's got more tread.

You'll not see hamilton on treaded tyres in the dry:smile: