Stock tire height?

**AKIRA** · 03-11-2009, 07:22 AM

I am surprised theres no sticky on this but here goes:

I have 17" all around and I just got my 2 front tires replaced. The height they put on were 45 and not 40. Now I have 40 in the back, but I coulda sworn I had 35 on the front.

Perhaps I am wrong. Since I got a good deal on the tires I am wondering if I should give too much of a shit over this.

Are 45s up front ok? (245/45/17)

**Mr. Luos** · 03-11-2009, 08:23 AM

245/45/17 is a 25.68" tall tire.
275/40/17 is a 25.66" tall tire.
315/35/17 is a 25.68" tall tire.

You should be okay.

**GULLETT17** · 03-11-2009, 09:12 AM

the sticky :
http://www.ls1.com/forums/showthread.php?t=80679

**ntimid8r** · 03-11-2009, 09:15 AM

Originally Posted by GULLETT17

the sticky :
http://www.ls1.com/forums/showthread.php?t=80679

**AKIRA** · 03-11-2009, 11:28 AM

Originally Posted by Mr. Luos

245/45/17 is a 25.68" tall tire.
275/40/17 is a 25.66" tall tire.
315/35/17 is a 25.68" tall tire.

You should be okay.

Holy shit really? I didnt know the differences were so minimal. Got to depend on brands though.

Ive got 285/40/17s on the back, so when he told me the deal on the 245s up front with the Goodyears (I had 235 BFGs), I didnt think it would matter, but I forgot the height.

That sticky wasnt "in yer face" enough for me. Sure it gave me parameters of height, but I didnt know what was stock.

Anyway, I suppose Ill just stick to these. Thanks.

**dklowrider** · 03-12-2009, 04:56 PM

the width numbers are metric, 245,275,etc. the /40,/45,etc is the aspect ratio. it measures the ratio of sidewall height to tire width. to keep the same overall diameter as you see in mr luos's post,when you go up numerically in width, you have to go down numerically in aspect ratio. if you have factory 17s i think they were equiped with 275/40/17s, a factory 16" should be 245/50/16 which is the same overall diameter, usually around 25.6" to 25.7". if you dont stick to the correct diameter your speedometer/odometer will be off. you could ive heard also cause malfunctions in the abs and traction control systems. your 285/40/17s are too big but maybe not enough to be a problem.