slicks on standard wheels info needed



i have standard wheels and want to buy sum slicks does anyone no wats the widest tyre i can go i want a 45 or 50 profile so there is a bit of squidge in the tyre :D wat tyre size do u reckon for maximum traction????????
i had an old set of R rims and they had a 205 width on the 14" rim but they looed at the limit for the wheel probably best to stick to a 195 for saftey but to be honest the 205 i had seemed to drive fine