I Have stock tires on my 2008 IS250 and it's time to replace they are 225/40r18 for the front which is what I need my question is their a better size I should get to get a better ride?

 

I would stick to the OEM factory size.

 

Thanks for the advise

 

You could probably get away with 235/40/18s up front and 265/40/18s in the rear if you wanted to "up-size". But unless you get a killer done the on the larger size tires, no need really; just stick with the factory tire specs.