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Which axle to put 2 new tyres on: Front Wheel Drive Car

michelin

Well-known member
Joined
28 Oct 2010
Messages
2,422
My Audi has two Vredenstein Sessanta's on the front which are 6 months old. I've now acquired another two new tyres for the car.
Am I correct in thinking that the two new tyres should go on the front and the existing front's should go to the rear?
The tyre fitter seems to think the new ones should go on the back :?:
:thumb:
 
I always thought the same as you.

BUT

After being advised differently by my local fitters I did some research and the widespread recommendation is that on fwd cars the best tyres should always be on the rear.
 
Thanks guys for the help.
I stand corrected, I always thought new tyres went on the front.
Tyre fitter was correct then. :thumb:
Thanks Guys.
 
Just to elaborate, and understanding always works better than learning a "rule" by rote:

There are least two reasons for prioritising the rear axle for new tyres:

1) rears never wear (OK, wear very slowly) and hence without forced rotation (to front) they would hardly get new tyres. Old tyres fatigue, crack and can burst due to weakened sidewall. Also, whereas road and kerb damage may not become problematic to relatively rapidly worn tyres (as the tyres are replaced due to wear long before damage causes issues), this is not the case for slowly worn tyres. So all those pot holse or kerb bruisings can and will damage and weaken sidewalls to the point of a much more insidious failure (blowout) long before it is time to replace due to wear.

2) in any car it is far more important to resist aquaplanning at the rear, as this is fundamentally the end that defines stability (and communicates teh least before breakaway).

Lose the front end and you plough on/run wide (also, especially in a FWD car, any loss of tread based grip is telegraphed much earlier in the wear cycle due to the extra steering and power feedback, long before cruising and braking grip is lost). Lose the back end and you suddenly aren't driving anymore, you are spinning and you have lost all control.

Aquaplanning is resisted entirely by tread depth (assuming the same tyre design). This is non-linear too, aquaplanning resistance drops much faster than tread depth drop.

By rotating the tyre based on front tyre usage means the rears are always 3/4-4/4 thread depth - certainly they can never run to fully worn.
 
What an explanantion!
As ever thank you GT4 (The true 911uk.com 'Oracle')
:thumb: :thumb:
 

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