Going to be replacing my tires here pretty soon and wondering who's running one over the other........any advantages or horror stories? I am going to be installing my coilovers here soon and would like to get rid of some of the sidewall as the car is lowered, but don't want to screw anything up going with a 40 instead of a 45.

Thanks!

 

On 40 you will run a bit higher in revs since the tire is smaller, but the advantage is taht you will accelerate faster =D
I personally run 205/40 during the summer and 205/50 during the winter and I CLEARLY see a ifference in acceleration..

You will have a bit more hard ride on 40

 

What Trizzz said and:

At 65mph your speedo will be about 2 mph more optimistic than it is now.
Your odometer will add about 338 miles for every 10k you drive.
Your turn-in to a corner will be a bit quicker.
Your ground clearance, wheel gap, and center of gravity will be about 4/10ths of an inch less/lower in addition to changes you make with coilovers.

Minor changes.

 

Great information thanks guys, and wish there was a way I could correct for the mileage on that but understand why it will happen.

 

The other thing to think about is aesthetics. My opinion is that the car looks lower when the wheel gap is reduced to the fender. Having a shorter tire (which actually lowers the car more) can make the car LOOK like it is not low, due to the greater visual gap.

I have read several threads here of people successfully running 215/45/17's, even on lowered cars. This may correct some of the speedo inaccuracy as well. This coming spring I will be moving to this size, but my car is not that low.

Have fun,
Mike

 

I run 215 45 17 and I love it.

 

+1 but not lowered

 

Not lowered but plan on doing it with struts next summer. I want good allignment