Choosing gear ratio.

[Dominic Toretto]

My car has a 3.15 rear end. Came with the gay 18s with 235/45/18s. I am lowered an inch with 285/35/19s, anyone know how that would effect my gear ratio?

-Alex

[Dominic Toretto]

Originally Posted by DirtyD Are your new wheels slightly shorter or taller than the old wheels? If shorter, it's a slightly shorter effective ratio. If taller, it's a slightly taller effective ratio.

Posted this above.

Originally Posted by Dominic Toretto My car has a 3.15 rear end. Came with the gay 18s with 235/45/18s. I am lowered an inch with 285/35/19s, anyone know how that would effect my gear ratio? -Alex

[DirtyD]

Originally Posted by Dominic Toretto Posted this above.

Missed that. I didn't realize the 18s came with such short tires.

[Dominic Toretto]

Originally Posted by DirtyD Missed that. I didn't realize the 18s came with such short tires.

Haha, thanks for second guessing, I had to check again. They were 235/50/18s stock.

-Alex

[DirtyD]

Originally Posted by Dominic Toretto Haha, thanks for second guessing, I had to check again. They were 235/50/18s stock. -Alex

That's what I was thinking. These cars come with at least 27" wheel/tire combos.

Your rear wheel is now about 1/4" shorter than stock, so your effective ratio when a little shorter to probably a 3.16. Lol

[my95z28]

Really good tire size calculator at this website. http://www.miata.net/garage/tirecalc.html

Gives you a visual of how the tires are sized differently, and a percentage of how far off your tires are. Yours are only 2%, so not that big of a drifference. You'll actually be going 2% faster than what your speedometer says, but thats such a small difference it will never matter.

[DirtyD]

Alex, it's probably now around a 3.13-3.14 effective ratio.

[Dominic Toretto]

Ah thanks guys. I didn't think the change was too drastic. I noticed my speedo hasn't changed at all.

-Alex

[DirtyD]

Originally Posted by Dominic Toretto Ah thanks guys. I didn't think the change was too drastic. I noticed my speedo hasn't changed at all. -Alex

Are your new wheels slightly shorter or taller than the old wheels?

If shorter, it's a slightly shorter effective ratio. If taller, it's a slightly taller effective ratio.

[Bacadiesel]

http://www.tacomaworld.com/forum/tirecalc.php

I like this tire calculator cuz it shows pics

[Bacadiesel]

Alex , your new wheel and tire combo is 0.53 inches taller

[Dan12GT]

Oh ya I went from 27.68 on stock 19s to 27.58 with the 20s on a slightly shorter tire. Heck ya I'm running like 3:31.5s now! On a serious note I'm definitely looking at doing 3:73s