Aftermarket Wheels for 2012 IS250 AWD

[jayvery]

Hello all, I recently bought a 2012 IS250 after previously owning a 2007 ES350.  I love the car but I don't like wheel size and styling of the factory wheels. My question is will 18x255x45/40 wheels fit on this model without causing problems?  I have never changed tire/wheel sizes on a car before. Thanks for any help in advance.

[RX400h]

It looks like the front tires are narrower and smaller in diameter than the rears. The 18-inch wheels that were available for upper trim levels used tires of size 225/40/18 for the front and 255/40/18 for the rear. I would think that the wheel width for the front is narrower than those for the rear. Your car may have 17-inch wheels and tires.

If I were you, I'd check with the folks at tirerack: Call 888-541-1777 

[bazzle]

AWD has same size rims and tyres all around. I believe 235/40/18 will fit ok and Rims can be 18x8 +45mm

Standard tyres are 225/40/17. 235's above are 10mm overall taller. Speedo will be ~1.5% out in your favour as speedo normally reads faster than real speed.

Standard rims are 17x8 +45mm. 

Tyre Size Calculator (tiresize.com)