In advance, a single acceptance would be due at the TÜV and I am aware of a speedometer alignment. Let’s say I have a small car with 185/60 R15 tyres, and now mount tyres in 195/65 R15 or 185/65 R15. How much would that improve the suspension comfort in practice? I found this computer:http://www.flat4.de/calc_tyr.htm The computer issues several comfort indices, the higher the more comfortable, I think these are all common sizes that promise more comfort: 185/60 R15 – 6,2 185/65 R15 – 7,7 195/65 R15 – 8,7 Would 195/65 R15 fit with a Mevira A, for example, without bodywork? Can the speedometer be adjusted at will or only within a certain tolerance? If 195/65 R15 were too much, would there be a noticeable improvement at 185/65? Are there any disadvantages other than possibly higher consumption, has anyone ever done the whole thing?