Converting numeric to current tire sizes.

[omgwtfbyobbq]

When I was fiddling around with my spare the other day, I realized it was OEM because it had "Made in Japan" on the sidewall, and then noticed it was significantly taller than my current set. So, I google and find that the tire rack has this nifty little chart. Unfortunately, it seems to be off, because according to it, the 700R14 OEM spare isn't as tall as the stockers on right now, but if you put it and one of the 195/75R14s next to each other there's a big difference. Even with less than 5lbs of air pressure, it was still way taller than all the others when mounted (and sagging).

Going off of a guess, I converted 14" (rim size) to mm and got that the diameter of the wheel/tire now was ~550mm. If I assume the diameter of the OEM full sized spare was 700mm, then things start making sense. And my gas longs start to really match up, when comparing my use of the odo previously to my current use of mapquest and "better" mileage. Hell, I'm going faster now and doing more heavy city, but my mileage has gone up by ~3mpg, hmmm...