I'm getting some mixed info on which wheels/tires I can put on my IS. It's a 2012 IS 250, RWD. Came with 18" alloy wheels (front: 225/40R18, rear: 255/40R18).

Under the "Tires and Wheels" section of the owner's manual, there are 5 dimensions of tires listed (Type A to E). Does this mean that I can use any tires with those specs? I am shopping for winter/snow tires and am hoping to get 4 tires/wheels of the same size, allowing for regular rotation and longer treadlife. Anyone have experience driving their IS RWD using 205/55R16 89W tires all around? (Type A setup according to manual). This would seem like the best setup for winter tires...relatively narrow (less slippage), and higher profile (longer treadlife).

I have called 2 lexus service centers near me and both have said that it's not advisable for me to switch wheel/tire sizes as this would mess with the way that the breaks/break drums align? However, tirerack techs said it wouldn't be a problem. Am I really stuck with my current wheel/tire configuration? I'm not sure where to get a definitive answer on this.

 

I beleave 16s are canda cars only. US don't come with it. As for winter I run 225-45-18 all around on my is350. No problem.

 

Canada used to do 16's but don't do it anymore.

Lexus Japan however does have 16" option.
http://lexus.jp/models/is/specificat...quipment0.html

 

Just a different question. For summer tires on the RWD; has anyone run the larger tires on the rear as well as the front tires for more rotation options?
Thanks,
Chris

 

^
Seems like you're asking about going all around the same size which would mean making the rear tire the same size as the fronts.

Yes, one can do that however it would look a bit awkward in a way since the vehicle looks like a AWD.

There is a bit of implications changing from stagger to non-stagger because it would change the handling balance, assuming one is aware of the current balance. It would affect all of the balance, acceleration, decelerating and cornering.