One for you tyre whizzo's. Given an vehicle weight of approx 1400kg (its a Forester) if I change from 225/55/16 to 205/60/16 what % less rubber will be in contact with the road surface. Question arises because I'm buying some winter tyres and the supplier is adament that I should drop the width. I understand the concept of less foot print equals more pressure but these tyres are going to be doing more road work than snow etc.

Regards Obi

 

Have look here: http://www.miata.net/garage/tirecalc.html
It doesn't look significantly less!!! Have a play with the sizes and go back to your supplier

Possibly a 185/65 or 175/70 if they will fit the wheels

I have no expierence with winter tyres, so the choice is down to you

 

The difference is marginal, but your supplier is right in theory. Thinner tyre has same grip but less prone to acquaplane. Also lighter and cheaper. I'm not a big fan of silly-low-profile tyres.

But, theory apart, some top quality rubber makes a huge difference. Toyo T1-S or Goodyear F1.

Cheers,

Richard.