I posted a while back about getting rims and just killing my mpg. I'd like to see some pics of what others have got for rims/tires, and what sort of mpg hit you took.
It appears you have a liftback according to your information. F8L probably knows a bunch about this subject over in the Gen III forum. If you have a Prius c, it may be a bit early to find any definitive information on the subject.
I lost about 4-5mpg with my setup. Wheels: Konig Helium 16x7 40mm offset Tires: Continental ExtremeContact DWS 195/50/16 front and 205/50/16 rear.. Read more: http://priuschat.com/threads/lowered-with-16x7-konig-195-50-front-205-50-rear.117812/#ixzz2CKW2W14U
It seems I timed my switchover from OEM to summer setup exactly when winter fuel blend was transitioning, so I'm not sure how much it's impacted. That said, a few days ago I put on my winter setup and it seems to be more efficient on the highway, but it's too early to tell. It's looking like deviating from the OEM tire and/or wheel makes mostly a bad impact on fuel consumption. Whether it's from the aero drag, rolling drag, or combinations of both. It would be good to read through the other wheel threads to see if people that put OEM tires on aftermarket wheels made a noticeable long-term fuel economy impact.
