no, i have a saxo 1.1 - the avantage is what i saw on the back of a zx estate. the wheels i've got are 155/75/13 (i think) and the 306 size is just about the right diameter without modding the arch liners
They have a larger rolling radius,
Current circumference: 1767.77 mm vs New circumference: 1809.56 mm 2.3 % gain
So when your speedo reads 70mph, you're actually travelling at 71.65 mph.
185/50/15 or 195/45/15 would give better rolling radia within 1% of your current.
