What size tires are supposed to be on the car?

Can you provide the last 8 of the VIN and I will confirm what you are seeing online is accurate. Then if this is the case that it calls for 18's and now it has 20's then someone has changed them. Did you just purchase this vehicle recently?

Let's start with the last 8 and I will confirm this is accurate and then go from there. Thanks

Okay. So someone did change this if it has 20 inch tires on it. As you can see it came with 18s as you found as well. So this is not an issue other then it will throw off the speedometer a little but you should not have any performance issues due to this. More recent vehicles you may have an issue but on a 2006 it should not effect anything else.

Let me know if you have questions.