The Energy Saver A/S is one of if not THE most fuel efficient tire we know of that is available in North America. Tests from TireRack.com has priced this as has my own physical testing and research. Compared to the OEM tire for the Prius, the Energy Saver A/S is approximately 5%-6% more efficient. TireRack testing showed a 3.8mpg increase over a fairly efficient Michelin Hydroedge and almost 3mpg more efficient than the OE Goodyear Integrity. My own testing averaged a 2.5-3mpg gain vs. the OE Yokohama AVID S33D.
There has been tons of posts on the Prius forum regarding the newest crop of LRR tires and thus far nothing really beats the Energy Saver A/S in terms of efficiency and lowest cost per mile while maintaining adequate grip, braking, longevity and comfort. The Bridgestone Ecopia EP100 was nearly as efficient but it has been discontinued and the Ecopia EP422 doesn't handle as well.
My point here is to make you think carefully about your next tire. As many Prius owners have found out too late, the OE tires are pretty efficient and going to a conventional non-LRR for added performance can really ding your fuel economy. For us it can be as much as a 3-5mpg drop (50 to 46 avg.). Because the CMAX already starts off with the most fuel efficient tire, the loss could be quite high for you.
I'm not a tire expert but I spend quite a bit of time researching fuel efficient tires and testing them when I have the money. If I can help you guys like I've helped my brothers and sisters on the Prius forums feel free to ask. I have created threads comparing tires and links to tests done by TireRack. If there is interest I would be happy to create one her for CMAX owners.
Edited by F8l, 13 April 2013 - 11:28 PM.