Going from 16" to 18" wheels - ride height or other issues?

[brad]

This is exactly what I've been considering. Is a 235/45 tyre as opposed to 225/45 legal though?

AFAIK as long as the speed & load ratings are >=. The width & height are both within (NSW) regs. I ran 235/45r17 on 17x8 ET35 from about 45k to 55k on OEM Elegance springs & they were great. The ET was a bit aggressive IMO & I would have preferred ET40-ET45 but the tyre size was great.

OEM 205/55r16 = ~632mm diameter
OEM 225/45r17 = ~634mm
OEM 225/40r18 = ~637mm
235/45r17 = ~643mm
225/55r16 = ~654mm -had these from 55k to 125k on 16x7.5 ET45 with Eibach lowered springs. Speedo was 4kmh (still safe) under & no rubbing.
225/50r17 = ~657mm - currently fitted on 17x7.5 ET42(?). Speedo is 100=100 (too close for comfort). Slightest rub on the front RHS inner guard liner if you hit a bump mid- LH corner. Great on the rear - not so great on the front. I think they'd be fine with OEM springs.

There used to be a big difference in price between 225/45r17 & 235/45 but it's only about $15 now