Ok i'm going from 235/35/19 front 19x8.5 +28 and rear is 275/30/19 19x10 +43

Well i want to put 225/35/19 and 275/35/19 is that going to affect me much? any concerns i should worry about?

 

front won't, but rear might, depends on how much you lower it.

 

Your dropping from an OD of 25.5" to an OD of 25.2" in front and going up from 25.6" to 26.6" in the rear. So, you're going from a difference front to rear of .3" (larger in front) to 1.4" (larger in rear) in diameter. You'll have a definite rake. Is that what you want? I'm not sure if the speedo/odo comes of the front or wheel. If it's the rear, that's a definite difference.

Lou

 

what is rake? Also speedo comes from rear wheel

 

Rake is when your car is angle lower in the front and the rear sits higher. Reverse rake is when you have a tucked rear and say a 2 finger gap front.

 

275/35/19 is way too tall for the the IS and will throw off your speedo/odo 275/30 is the correct size in that width. Or you could go with a 255/35 if you want the 35 series in the rear, but the sidewall is not much different going from one size to the other. Remember that the series is a percentage of the width.

If you ran 225/35F 255/35R you would be almost identical with stock rolling diameter, which is already raked.

 

275/30/19 will also throw off your speedo by 2.0xx percent.

 

As long as it is within 3% it wont have any adverse affects on the speedo or odo.

 

265/35/19 in the rear affect the speedo or odo?

 

I have a 265/35/19 rear tire mounted on 19 x 9.5 wheel. It is the closest you'll get to the diameter of the stock wheels and tires, (in the rear) so if anything this would have the least affect on the speedo/odo. Be warned though that this is a very odd size for some reason, and the few brands that have this size available are usually expensive.

 

yea 265/35/19 are very odd sizes and pretty much 1.5 times the size of 275/30/19 and 275/35/19