Replacing tyres on a Mercedes A class.

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Mon 15 Jul 2002 21:30
Replacing tyres on a Mercedes A class. - peteH
As everyone will be aware there is some discussion regarding placing the new tyres at the front or rear

I thought it would be useful to post the following information for future reference.

I have a Mercedes A140 that required new front tyres (currently Continental EP 195/50 R15)

Continentals general advice is "Irrespective if the vehicle is FWD or RWD in general the new replacement tyres should be fitted to the rear wheels of the vehicle." but also recommend to "Refer to the vehicle manufacturer’s recommendations"

The advice of Mercedes is to fit the new tyres where the old ones are removed (i.e on the Front). In addition Mercedes do not recommend rotation of tyres on the A class range.

There does not appear to be a "cut and dried" reason for fitting to front or rear? From what I understand the "fit to rear" is to reduce the posibility of a rear breakout. With more modern cars with ESP - possibility and loss of control of a rear breakout is already reduced, and hence the recommendation by Mercedes.








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Mon 15 Jul 2002 22:13
Replacing tyres on a Mercedes A class. - Dizzy {P}
I've thought about this again since we last discussed it on this forum. I still think that understeer is preferable to oversteer on most cars and this, if you remember, was the reason given for putting the best tyres on the back. However ...

When we talk of putting the tyres with most tread on the wheels that must retain grip, (arguably the rear wheels) I assume this applies only on a very wet road where a deep tread is required to shift the water. But if the 'old' tyres on the front don't have enough tread to disperse the water then we are in trouble anyway, possibly from aquaplaning.

From this, I have arrived at a personal conclusion that it doesn't really matter where the two new tyres are fitted so long as the other two tyres have a good tread depth - and if they haven't, they need replacing anyway.

It is my view also that rotation is of little benefit. In fact I believe it can be detrimental to the life of the tyre, and to its performance for a while after rotation, because the profile of a rear tyre may well be different to that of a front tyre and so they may have different 'footprints' until they bed in (ie. wear in) to their new position.
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Tue 16 Jul 2002 00:08
Replacing tyres on a Mercedes A class. - peteH
Agreed.

It addition as front tyre wear is higher than rear tyre wear (in this case), assuming the old rears have 6mm tread, and the new fronts 8mm wear - very quickly the front tyres will wear to less tread depth than the rears - making the "better" tyres on the rear again.

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