Over the last few years I have seen many tire related threads, but this one is more interesting than the usual, it is just such an odd size. All I see now is 18+".
I'm curious to see the alignment angles of the roadster. Does anyone have a scanned printout handy?
How are these tires wearing, inside, outside, featheredged?
The tires that are pictured have tread blocks that are far too solid for a daily driver in anything but ideal conditions.
If I had to choose between the two I would prefer the wider aspect ratio and slightly smaller sidewall. The Michelin Exalto is a decent tire on passenger cars but how it would act on a Roadster remains to be seen.
Continental has several offerings in the larger size.
The Contis have the ablility to be cross rotated regularly, which in theory should prolong them. Also the ones in the photo above have blocks that look like they would tolerate the negative camber better than the factory tires.