GaryCat

My 03 WRX has just failed it's MOT as there is a cut in the front tyre so I am going to replace both fronts as the other one is down to about 3-4mm but do I need to change the rears as well - they have about 4mm so will be slightly different to the new ones with 7-8mm or whatever.

I'll be fitting the same make as the existing rears - Goodyear F1 GSD3s

Does it make a big difference to the centre viscous diff?

Steve Whitehorn

iTrader: (13)

My understanding is no it wont effect the diff.
Allways change pairs as you are doing
Steve

s70rjw

iTrader: (2)

As above, just make sure the same axle has the same depth/ pattern. Are you running the XL F1's

MScrivener

Always replace in pairs and the new ones go on the rear - apparently people find it harder to handle a rear skid hence why new ones go on rear - they will be a bit slippery until run in.
How much did they cost you?
I've just put on Pirelli P Zero Nero as they Asymetrico's were £140 each!
Matt