Originally Posted by timmytVA
Windsailor, I have the Ti Handling package with the 18" wheels and sticky Michelins. I love the ride / handling balance the package has but am seriously wondering what the MPG effect is.
If others are averaging, say 27 MPG in driving conditions similar to mine, and I'm averaging 22 - can the 18" wheels and tires really be a 30% hit? I don't thik I thrash my car too excessively.
I am not entirely sure but what made me think of it was the idea that the SFE package, which comes with wheel covers that block off the air passage through the wheels, is worth 2 MPG highway. The 18" package is wider and may add to the frontal area. If the Focus is that sensitive that a wheel cover can make 2 MPG difference then wider tires and wheels may have an impact.
Two cars side by side, one with 16" and one with 18", doing a coastdown would verify.
In the meantime if those that are struggling to get to the numbers being posted for FE are all 18" Sport Package Titanium then that would start to fill in a pattern.