I'm thinking of changing the alloys on my Signum Elite for an new set of 18"s. Has anyone who has also changed to 18"s noticed that their tyres wear more quickly than the 17"s. Now I know that it will largely depend on the type of tyre used but has anyone any experience / advice. I do about 25k miles a year so don't want to end up having to spend a fortune on changing tyres all year long!!