Winter tire 1m discussion

[EldRick]

moving from 19s to 18s also makes everything lower...

It shouldn't do so - the mounted tire radius is within a mm or two, because you are losing 12.5mm on the wheel size, but gaining 12.75 on the tire by going to a 40-section tire instead of 35-section.

[IEDEI]

Originally Posted by EldRick

It shouldn't do so - the mounted tire radius is within a mm or two, because you are losing 12.5mm on the wheel size, but gaining 12.75 on the tire by going to a 40-section tire instead of 35-section.

it's not so straightforward i think!

i used this calculator and plugged in the numbers and found you still lose more than 7 mm with the winter setup.

http://www.willtheyfit.com/

[EldRick]

Right - I was thinking only of the front. The rear drop is greater, but there is more clearance back there.
With the 235x40x18, I was scraping at the front on my driveway in places where I did not with summer tires.

[EldRick]

And I'm happy to report that the 245x40x18 Blizzak WS80 hasn't chewed up the new-version fender liner - at least not after the first 50 miles.
They should be at least as good a rain tire, and a far better snow/ice tire than the PA3's they replaced. And they buy me a few more mm of ride height.