Wow!
I was way off. I am trying to match the original diameter or better. I think I got 175 70 15 currently. I wanted to get something just a bit larger and wider.
175/70/15 = 24.64\"s high
165/80/15 = 25.39\"s high
165mm (the tread width, the area that contacts the road)
80% (the aspect ratio, or sidewall. 80% of 165mm is the sidewall height. then you multiply that # by 2 and add the diameter of the rim to get the total height of the rim & tire combo)
15\" (the rim diameter)
so...
165/80/15 is...
165mm tread width
80% of 165mm = 132mm x 2 = 264mm
divide 264mm by 25.4 (25.4mm = 1\") to get inches = 10.39\"s
add 15\"s of rim diameter to get total rim & tire height of 25.39\"s
all this can be done with a simple calculator or you can play with the link that chris posted.
205/65/15 = 25.49\"s high. very close to the height of a stock rim & tire. but...a 205 is wider than a stock setup by 1.57\"s.
hope that wasnt too confusing. it makes sense to me but i have difficulty explaining things sometimes.
good luck with the tire search emilio.