Here's my brochure. It's older than yours - mid 2008?

The reason the 45 series works on a 7" rim is because it does have an extra 1/4" of sidewall height. Because of the extra height/pivot length, it can balloon a bit more & therefore fits (just). I help run a website that used to have a lot of RB Liberty owners - it was a recurring question because the Libs had 7x18 with 225/45x18. This size is uncommon (and a Ferrari front size) & therefore expensive (not as bad now as it was a few years back).
Here's the specs on Michelin PS2 (but Goodyear F1A & other popular choices are the same). 225/40x18 at the top (recomended rim range 7.5"-9"); hunt down towards the middle for 225/45x18 (7"-8.5")....... doesn't make sense but that's how it works.
As I said, i'd remove a wheel & have a look just to make sure.

The reason the 45 series works on a 7" rim is because it does have an extra 1/4" of sidewall height. Because of the extra height/pivot length, it can balloon a bit more & therefore fits (just). I help run a website that used to have a lot of RB Liberty owners - it was a recurring question because the Libs had 7x18 with 225/45x18. This size is uncommon (and a Ferrari front size) & therefore expensive (not as bad now as it was a few years back).
Here's the specs on Michelin PS2 (but Goodyear F1A & other popular choices are the same). 225/40x18 at the top (recomended rim range 7.5"-9"); hunt down towards the middle for 225/45x18 (7"-8.5")....... doesn't make sense but that's how it works.
As I said, i'd remove a wheel & have a look just to make sure.
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