F8L

I took special note that the CMAX may come equipped with Michelin Energy Saver A/S tires. My experience with this tire is limited to the 15" size but having tested a large number of other LRR 17" tires it appears the Energy Saver A/S is the most fuel efficient tire we have in North America. My point? I would be very careful when it comes time to replace them. Most other LRR tires are simply not as efficient. :( I'm not a tire expert but I spend hours daily researching LRR tires for people on our Prius, TDi and EcoModder forums. In case you have not read this test yet. http://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=121

There are many reasons why fuel economy will drop in winter weather. The biggest factors are winter blend fuel vs. summer blend, increased aerodynamic drag, increased tire rolling resistance (even when roads are dry), increased warm up times, etc.. Summertime is when you'll start seeing record tanks. This is assuming you can keep the air conditioning to a minimum. ;) In my cars, the difference in fuel economy at 30F vs. 95F can be quite dramatic! I look forward to seeing what you guys get in warmer weather. :)

This is something I struggled to try and understand. The 15" tires are much more fuel efficient but the handling is rather poor compared to 17s. The CMAX is simply too heavy and too geared for handling to suffer with 15s. In my years of testing 15s and 17s on the Prius, there is always an immediate loss of 3-8mpg depending on tire and wheel choices. I have found the 15" Energy Saver A/S to be the most fuel efficient tire in North America. That means you CMAX owners are going to lose even more mpg should you swap to a less efficient tire. :(