I'm trying to find a decent way to lower rpm at highway speeds. My wife would also like a little softer ride than the 205/40/17s are supplying. I'm thinking either 215/45 or 225/45, but don't know if 225s would be too tall, too heavy, or hurt mileage or performance. I'll definitely be adding spacers of at least 15 mm in back. 205/40 to 225/45 would be an increase of 1.6" total height, from 23.4" to 25" (Kumho 711). Wheels have +37mm offset. Thx.

I'm trying to find a decent way to lower rpm at highway speeds. My wife would also like a little softer ride than the 205/40/17s are supplying. I'm thinking either 215/45 or 225/45, but don't know if 225s would be too tall, too heavy, or hurt mileage or performance. I'll definitely be adding spacers of at least 15 mm in back. 205/40 to 225/45 would be an increase of 1.6" total height, from 23.4" to 25" (Kumho 711). Wheels have +37mm offset. Thx.[/b]


I run 215/45/17 with a 2" drop and It rides really nice, not too much different than stock. I don't know if you can go any bigger without rubbing. :wink:

but don't know if 225s would be too tall,

225 would be the tread width... not how tall it is...

if you are worried about a smoother ride, go to 16's or even 15's

but don't know if 225s would be too tall,

225 would be the tread width... not how tall it is...

if you are worried about a smoother ride, go to 16's or even 15's

The width matters because the side wall is a function of the tire width.
I have 225 40 18 and it rides very nicely. I have Kumho 711 which are not high performance tires ( but neither is the car) and they ride super quietly.
My wheel/tire combo is about 1" taller and it does lower the RPM at highway speeds.
How much" I don't know exactly, but a guestimate would be around 200 RPM less at about 70 MPh

but don't know if 225s would be too tall,

225 would be the tread width... not how tall it is...

if you are worried about a smoother ride, go to 16's or even 15's
i think he's compairing 215/45 to 225/45, and yes it will still be taller than 215/45(0.2 inch difference).

btw, if you're going with it, let us know how it goes. what is your wheel specs(width, offset) and is the box lowered?
I want to go that way on my next rubber(2-3 years later)
I have 215/45/17 on 7" et 38 lowered s-tech(1.7, 1.5) and no rubbing. rides is not bad at all.

oh and one other thing . 205/40/17 is small , 205/45/17 is a better choice. but yeah the bigger the tire , the slower yer car is and the worse mpg u get so..... a heavier , taller tire may lower rpms but u will still be getting ____ty gas mileage from the added unsprung weight. try some 15 or 16s with tall tires , try like a 195 or 205/60 15

Sid, I have 17x7" +37, stock ride height. No new springs planned, so that won't be an issue. I'm more concerned about the added weight of wider tires.

Looks like 215/45 may be the way to go. Thanks guys.

:no: Be careful bro, running a bigger tire will help your ride, but trying to get the RPM's down will change the accuaccy of your speedo.
Over all dia of a stock tire is about 25.39"
The 215/45/17 is 24.6"

My 225/35/20 is 26.2, and it throws my speedo off around 5-8 MPH... I think.

Just letting you know, BTW I got most of my info off Nitto's website. I did the math for
the stock tire myself.

Good luck!

Yeah, I know there will be a little change in speedo readings, but my wife hardly ever approaches the "ticket" range any way. Thanks for the input. Now I'm debating 225/45s or 215/45s.