Shouldn't be too far out. Original would probably be 185/60/14s or 185/65/14s which would be a size change of 0.4% and 3.4% respectively. Either way your speedo is going to read under by either nothing or about 3km/h at 100. Doesn't it say somewhere on the car what size tyres it came with factory? Knew I should have been paying attention when I was being told something about it
If its anything like mine the standard tire size should be 195/55/15
Depends on which year your car is, the easiest way is to post your chassis number here and i'll have a looksie for you, it should be located on the firewall under the bonnet and should be something like: E-AE111-ACMVF
Subaru GF8 Wagon Subaru GC8 rally car project http://www.hccc.org.nz - Keep up to date with all motorsport events in the Wellington region