That's what it looks like it'll take to be a full-size spare for the R55, without modifying the spare well cover. Maybe 7.5" at the absolute maximum.

There seem to be quite a few 17" rims in the 5.5-6.6" range (though most of them are on the much-too-expensive side), but the smallest non-directional 17" tire I've been able to find is the Nitto Neo Gen, which is 8.23" wide overall.

Have I missed something in my search, or is there simply not a solution here?

Thanks!

= Mike

Kumho Ecsta 4X has an 8.1" section width. As far as wheels, the smallest I have is 7"

Mike, have you looked at the JCW spare wheel? It's a 17x5.5 sizing (OEM P/N #36116786220)
And it uses a 185/50-R17 tire.

- Erik

Erik,

The wheel looks great, thanks.

Sadly the tire that's fitted is a Dunlop Winter Sport 3D, which is both directional and not available in the USA. So near, and yet so far. 8)

Really the open question is just whether it's safe to run it backwards for any length of time, I guess. It's going to be sufficiently off-kilter that it's not like sacrificing a little more traction is a big deal. And where you'd get a replacement tire if it ever had to be replaced...

= Mike

It is acceptable to run the tire backwards, your in no danger doing so. The pumping or channeling effect for water and slush will not work as intended, so be careful in those conditions.

Alex, thanks for that; it's very helpful.

I'm actually a habitual TireRack customer (first purchase was a set of RE71's for my 944); I'd be doing this through you guys if I could (and certainly as soon as I can kill the RF's I'll be back...)

= Mike