Tyre sizes for wider aftermarket wheels

[TrevS]

Hi all

I'm looking at posibly purchasing a set of BC forged wheels for my Evora S. I've been chatting to Hethelsport on sizes and am getting closer to chosing the right size and offset for the wheels but need some help on tyres. The sizes I'm looking at are

Front - 19 x 8.5"  +47.0 mm

Rear - Two options:
20 x 10" +63.0 mm
20 x 10.5" +69.0 mm

For tyres I would like to go with something like a Michellin Pilot Sport 4S or a Conti Sport Contact 7 as I don't want anything too agressive like a supersport. I think a 235/35 R19 (front) will fit fine on the 8.5" fronts and the 275/30 R20(rear) will fit the 10" rear but not sure what width tyre I would need for a 10.5" wheel, a 285 or 295 perhaps?

Any help would be much appreciated.

Thanks

Trev

[jerzybondov]

I put 285/30/20 Conti Sport 7s on mine (standard 20" wheel) and they were great. Maybe the right compromise in terms of not increasing the effective gearing too much? 

[mik]

Some sites like Toyo provide a range of wheel rim widths that they recommend for any specific tyre size.

You'll see from that link that a 285/30/20 (which my Sports Racer has always run on since I had it - the original owner replacing the OEM 275/30/20 Pirelli's with the slightly wider Michelins that Lotus fitted to the 400 and beyond) will fit on a 10" or a 10.5" wheel, but you could go to a 295/30/20 too. Lotus fitted a 295/30/20 on a 10" rear for the GT430.

[EGTE]

I rate Contis highly, but for me it's impossible to beat the performance AND longevity of Michelins; in the long run, they work out very reasonably because they last longer. My GT410 had PS4S as standard.