Yes, all things being equal you will increase inertia by increasing the height of the tire (aspect ratio). I don't know about rolling resistance. Most of the time, increased aspect tires weigh less, and you can further decrease weight and resistance by decreasing the section width. It makes a lot of sense to install a lower performance oriented wheel/tire combo for daily driving. Not only will it increase mpg, but it will also improve the ride and decrease tramlining, and possibly decrease wear of your expensive suspension components as more impact is absorbed by the less agressive wheel/tire! Makes a lot of sense in fact. Especially if you live in the midwest, say, where you encounter mainly 4 lane "slogging" roads.

 

Great, thank you for that info!! I've got some of the old forged 19's from my G35 I may use, I think they are quite a bit lighter weight!!