tyre wheel size and pressure

[iomgt6]

Hi All, I have 165/70 x 13 on front and 175/70 x13 on rear alloys what pressure should I put in these for general driving, the manual states 20 psi front and 24 psi rear but of course this is for standard wheels, what is the max width wheel size I could put on the rear without modifying arches, finally would the car handle better with a larger diameter wheel and low profile tyre but maintain speedo accuracy, sorry if this has been asked before, grateful for your thoughts, Paul

[Clive]

1. Is this a rotoflex car?If not go no lower than a 70 profile on the rear. With rotoflex 60 profile works well for me (185/60 14)

Pressures: Mine is a spitfire, with rotoflex. Having tried various pressures, I have settled on 25psi all round. Harder made the rear skittish (this was tried out over a number of sessions on a trackday) but you may need to experiment and find what works for you and your setup.