Hello all,
I had my grief with RFT and 19 inch wheels (I don't want to bore you with details, since I no longer have the Z4).
I just like to pass on the tip I got from a Tire Shop Manager in the US that has seen many Z4's rear tire wear. He said;-
"If you go for a trip with luggage in the trunk and lot's of driving with the top down then make sure your tire pressure is to spec. and add at least 2 PSI above specification to the rear tires"
He went on
"also your rear wheel camber is -2.5 degree your rear tires will last longer as will your rear wheels if you have that reduced to -1 or -1.5 degree"
Anyway that is what he said, take it for what it's worth .... just passing it on to you.
Happy and safe driving with your car once the snow melts
