set of 5 spoke 18's with 215/40 tyres

How come you went with 215/40s rather than 225/40s ?

7 inch wide rims, 215 gives a nice "square" look 225 is the biggest you can fit but looks more like a balloon. As I went from a 205/55 x 16 the 215/40 is closer to the original rolling diameter than the 225/40 (gives an actual 29.9 mph rather than 30.3 mph at an indicated 30mph) and I prefer the squarer look.

Ah it's because they're 7s! Probably best fit then - on my 8s a 225/40 works well