So I drive a 2015 is350 AWD F2.
I recent got winter tires on my car. 235/40/18 for the fromy stock rims and 265/40/18 for the rears.

I know the stock wheel sizes are 225/40/18 and 255/35/18.

I have my tires on for about 3 weeks now and no issues.
i did a pull last night, got to 130kms. And then let off and as I was coming down. The ⚠️CHECK AWD came up.

What is happening? Is it because my tire profile size is bigger then stock. ie. 40 and not 35 for the rear?

Is this bad for the AWD system, I thought as long as the wheels have a same rolling diameter or even slight off should be fine?

Pls help!!

 

To match front wheels diameter 235/40 with the rear ones you need 265/35 on the rear axle. 265/40 is taller tire than 235/40 that’s why you have warning ⚠️ on your dash.

 

 

As the aspect ratio for the front and rear are the same (40), then the tire width would have to be the same to avoid any issues.
I'm surprised the message didn't pop up sooner.
The rear tires are three sizes bigger than the front...one member had rears that were two sizes bigger than the front and the light came on pretty much right away.
Downsize the rear as indicated above and you'll be fine.

 

If i ran 235/40/18 all around would that be fine? Winters only

Stock rims

 

That would be fine...technically a 235/40/18 would fit an 8 to 9.5 rim...with the ideal fitment at 8.5.
It might look like a little pinch on the front for fitment, but won't impact the AWD system.

 

Thank so much!!!

LOVE YOU GUYS! lol

 

You can also run 225/40 all around to for winter narrow tire better for winter than wider tire.