I just changed my coupe's 17" tires from 225/50 & 235/50 (v-rated) to 235/45 & 245/45 (z-rated). I went with the ContiExtremes because I didn't feel as 'sure-footed' with the stock Goodyears. Anyway, the ride seems a little rougher now & I feel some steering vibration above 80mph.

Could this be due to balancing?
Are the tire sizes appropriate?
Are the car's specs thrown off a bit?

please advise...thanks

 

use the tire calculator, the first post of this forum to figure out if the diameter is the same. you want to be as close to stock diameter as possible or you VDC will be going crazy causing premature brake wear and tire wear. as for the vibration goes it could be do to balancing, if that is not the case it could be the tires, by the way are the extremes the tires that have a wierd side wall.

 

thanks...I've done that; I'm just not sure what's acceptable as far as being 'close enough' to stock diameter...any input?!?!

Very pleased with the extremes. Not sure what you mean by weird side walls...they have the directional arrows, which I think adds to the appearance. Got them for the looks and exceptional rating for rain/snow traction...pretty impressive for all-season tires.

 

"thanks...I've done that; I'm just not sure what's acceptable as far as being 'close enough' to stock diameter...any input?!?!"

well the fronts are -2.1% difference and the rears are -2.2% difference me personally would not be too concered about it, if you want a concrete answer you may want to call infiniti.

"Not sure what you mean by weird side walls..."

this is what i mean...