Who is good at math? (tire size question)

[Gr8dave37]

Ok...so right now I have 225/40r18's on my car and it is lowered with the tanabe springs. The ride has been a little rough since I got it and figured maybe if I added a little more rubber, I could smooth the ride out a bit.

So what I'm reading is that in the same width, I can get 225's in a 45, 50, 55, or 60...with the car lowered...anyone know what the max fit would be?

[blindsnyper]

225/45-18 tires are .9 inches taller than 225/40-18225/50-18 -- 1.8225/55-18 -- 2.6

the largest tires ive seen on a V or 215/50-17, 1 inch taller than stock. your current tire size is .6 inch taller than stock....

i just confused myself

[feloniousmonk]

Bookmark this one: http://www.miata.net/garage/tirecalc.html

[AZhitman]

Bad idea.

First, you're killing your ride with thin sidewalls as it is. Second, you're going to be adding more overall diameter, weight, and rolling resistance, not to mention overloading already overloaded brakes.

[OriginalWheelman]

http://www.1010tires.com/tiresizecalculator.asp