Why was cost even a factor? I mean if this is a budget thing then what does the cost or point even matter? The wheel on any car is the issue here. I think like yourself we could sit here all day long and say why are the worlds top track cars running 18"s and you know what? It wouldn't matter to the mentality of this forum ( not speaking for everyone ). You could show links to where Tire manufacture's work in conjunction with automaker's on what tire options to make more available for the up coming models each year that show. The market is moving more to 18" rims. Even if I posted this write up on track rims/tires from John Purner of CCW it doesn't matter. There will always' be a ( I don't care, I'm right ) here. This was never my point but like I said before. It's easier to just look away on here, then to reply asking questions. Otherwise you will spend your whole day ( if you care ) bricking back and forth on topic's in a childish behavior.
