Real-world sizing experience with Conti ECF?

As we all know, tire sizing is not always exactly truthful.  I'm thinking of running a WRL race next year (they're coming to Utah, which is within acceptable range of NorCal) and the ECF seems to be the spec tire.  I run 18s on my E46 M3, Conti has a 275/35 and a 295/30.  The car has had moderate amounts of fender work already and I know a 295 Toyo RR fits but a 295 Hoosier R7 does not.

Anyone know if the Conti is sized more like a Toyo or a Hoosier?

I could give you the measurements of a 245/40R18 ECF if you'd like. Sizing seems quite conventional.

Yep.  Sized "normal".

In my experience, the Conti ECF has a wider section width in a given sizing than a RE71RS.  This is measured with a carpenter's square on my garage floor; inches are the left most scale.

275/35R18 on a 9.5" wheel


295/30R18 on a 10.5" wheel

flyin_viata said:

In my experience, the Conti ECF has a wider section width in a given sizing than a RE71RS.  This is measured with a carpenter's square on my garage floor; inches are the left most scale.
 

Thanks!  I have some RE71RS in 275s, so that's a super useful comparison.

What other scale do they have on a carpenter's square that is bigger than inches??? :)

Haha...they're both inches (verified with another tape), but the left is outside and right is inside the 90.  Admittedly not sure why the outside is twelfths instead of sixteenths, though...mongo not good builder person