Min size of 205/55/16 with 93 load rating and V speed rated. Summer tyres should be W rated.
This is unless you have one of the 1.6 engined vehicles then you can have 195/65/15 91 load and V rated summer or H rated winters. Larger engines need the above as stated as minimum.
General rule of thumb is allowing 1 speed index drop between summer and winters.
Okay, on a follow up check it appears I have jumped the gun and the 15" is applicable for the 1.6, 1.8 & 2.0 petrol but the 2.0D upwards including 2.4 petrol all require the 16". I do apologise.
