First post, so please be gentle. I've just taken ownership of a 300SL (R129) 1991 Model. Needs a few little things to get it back to it's former glory, bit of paint, bit of upholstery and unfortunately the job of sorting out the wheels. The car came with a set of AMG Monoblock style split rims. Although they actually looked great, they are replicas. The outer rim was chewed up a bit on 3 of the wheels, so I've had them cut and re-polished and will get the middle section painted up myself. The question I have from a more technical view is regarding tyres. The old tyres were probably contributing to the ease of kerb damage, so would it be okay to buy a wider tyre? Current fitting is 235 40 18 at the front and 265 40 18 at the back. Could I go wider say 245 and 275? I'm not keen on dropping the profile, I think 40 fills the gap with the height of the motor perfectly well. Similarly on my daily runner, I have a set of 19 MV4 rims on a BMW (sorry). The standard fitment is 225 35 19 at the front and 255 30 19 at the back. Can I INCREASE the profile, or does that affect the speedo? Any technical advice would be appreciated!