question on tires

[StealthMode]

I put Si wheels on my EG some time ago, but i have always had the feeling that the tires are too big. I just got them done a discount, because I didn't have the money to get good tires, so I'm stick with the khumo's for now. anyways, the size is 195-55-15. i don't know what number refers to the profile of the tire, but it seems that this is the number for the tires that came on the factory Si wheels, and fit into the coupes better. they come with 14's (just the regular ones, not the si's) but my car comes stock with 13's. i'm wondering if i should go with a lower profile tire whenever I get a chance to redo them?

 

[phunky.buddha]

What's your stock tire size? Match the diameter of your new tires to the diameter of your old tires and you'll be fine. The 195/55/15 tire is too tall for a stock D series drivetrain. Here's how the math works so you can figure it out for yourself:

195 = section width (millimeters)
55 = profile (percentage)
15 = wheel size (inches)

Diameter = section width * 2(profile/100) + (wheel size)*(25.4)

That will get you : 195 * 2*55/100 + 15*25.4 = 595.5mm

If your stock tire size is 175/70/13 (most Civics from 88-00) then your stock tire diameter is 575.2mm. That's almost an inch smaller than what you're running right now, and is making your overall gearing quite a bit taller than stock. A 195/50/15 matches the 175/70/13 almost perfectly at 576mm.

Do the math, then find out which tire is a perfect fit for your car.