I'm thinking of getting some 15" G60 steel wheels for the arosa and was wondering what to do about tyre pressures? I just want more of a footprint on the road and I like the look of these wheels. As far as tyres go, I'm not after super low profile or stupidly wide, perhaps some 185/55/15s? Anyone got any ideas? Will it affect the speedo in any way as there will be a 2" difference in the size of the wheels?