Last930

Can anyone tell me if the outside diameter of a 265/35/18 tire is the same as a 295/30/18? I am looking at snow tires to fit the stock 8 &11" wheels and Tire Rack says nobody sells a 295/30 snow tire. I would rather not buy a pair of 10" rear wheels if a 265/35 would work without causing problems with the AWD system.

Joe Weinstein

say what brand, and then the tirerack site will give you the
actual OD. I am running just those sizes.

whiteturbo

http://www.miata.net/garage/tirecalc.html

This is a good site that you can compare sizes.

Last930

I am interested in using Pirelli Snowsport 240's on the stock TT 8 and 11" wheels. The Miata calculator shows the circumference to be:

225/40/18 78.8"
265/35/18 79.5"

That's a difference of 7/10th's of an inch - will that cause any problems with the AWD system? I would not think so , but don't want to mess it up.

Joe Weinstein

Here's a repeat of a post I made about using
any of those online tire size calculators:

Never, never use any online 'tire size calculator' if you are
dealing with close tolerances, such as trying to prevent
rubbing, or if you need exact diameters. They all mean
well, and are simply designed according to what the tire
size nomenclarure is *supposed* to mean, but in the real
world there is a wide range of variance between what a
tire is designated as and what it's real dimensions are.
For the real facts you have to go to the tire manufacturers
spec sheet. I have seen two different 245/45-16 tires differ
in diameter by 1/2 inch *from the same manufacturer*!
They were just different model tires. Recently one tire
manufacturer stopped making it's 305/30-18. Now they list
a 315/30-18. *It's the same tire*! They just decided that
the actual tire dimensions were closer to the 315 meaning,
so after 6 years they just changed what was printed on the
sidewall.

Joe Weinstein

Joe Weinstein

For the real dimensions, go to:

http://www.tirerack.com/tires/Spec.j...+240+SnowSport

The diameter of the 265-35-18 is 25.2" so the circumference is 79.1"

Last930

Thanks. Joe - what tire are you using? Tire Rack doesn't show any max performance winter tires in 225/40/18 and 265/35/18, although that could be because it's near the end of their winter tire season.
I have used Blizzak s and Snowsports in the past and liked them both.

Joe Weinstein

Hi. I am in California. 'Winter tires' for me are ones that have detectable tread left. Summer
tires are slicks. I'm just saying that you choose your brand and model tire, and then look
at the spec sheet to know the diameters. Compare them to tires you know are OK.

Richard.

My Winter Blizzaks make so much road noise on my 11 inch wide rears it is boarder line unbearable