Original tire size

[browntown]

I read a post here:

http://www.r3vlimited.com/board/showpost.php?p=811213&postcount=21

Talking about different stock tire sizes. This is something that I stumbled on inventorying my dozen bottlecaps. The spare tire in my old 85 eta which had never been touched and still has a perfect tire on it is a 195/60/14. In fact my eta had 195/60's on it for most of it's life.

Using the miata wheel size calculator, that size is undersized compared to the usual 195/65/14 that is considered the stock size.

If the factory stocked two different tire sizes, are some speedo's calibrated differently than others?

Makes the prospect of using 205/50/15's on 15" rims seem normal instead of the convential wisdom that they're undersized. Wonder if the GOD fellow who wrote in the above post was on to something.

[asubimmer]

65, look on tirerack if you want to confirm it

[browntown]

^^ bordering on a pointless response. I'm pretty sure some cars stock had 60. Someone else has to check their spare for the 60 series goodyear.

[asubimmer]

^^ bordering on a pointless response. I'm pretty sure some cars stock had 60. Someone else has to check their spare for the 60 series goodyear.

lol its a conspiracy.....

ps lay off the drugs it'll be alright

[browntown]

mystikal enlightened the maxbimmer guys on the very subject

http://www.maxbimmer.com/forums/showthread.php?t=54146

For tire sizing, RWD E30s used two different rolling diameters, 195/60/14 and 195/65/14. The larger 195/65 was used on plastic bumper cars, but that diameter will fit just fine on all models, and provide a more accurate speedometer (they all read quite high stock).

[Mystikal]

Yeah, what I said!

Early cars = 195/60
Late cars = 195/65

On a side note, this is why I never recommend tires taller than the 24" that the 195/65's measure. Fact is, our wheel wells (especially the fronts) were only designed for a 23.2" tire. Even running a 24" is at the limit for what the chassis can swallow (both front and rear of the tire in the front as well as up top as the chassis seam).