[Kodak]

40mpg is already pretty high Ultra-Orange. Do the same math with a 30mpg car, and you'll break even much sooner. Do the same math with a 50mpg car, and you'll break even much later, due to diminishing returns.

Your math is pretty sensible, but I want to say 2 things: First I think that the initial 9% claim needs substantiation from Michelin. What tire are they comparing to? They probably compared it to a second leading tire in that class. Secondly, I think that LRR tires have a dual effect for hypermilers - the first of course being lower resistance to get (and keep) the car moving, but the second being the potential for longer coasts. That is why I believe that hypermilers have the potential to see better gains from LRR's, if they take advantage of them.

I suspect that LRR tires are a nice 'set it and forget it' ecomod for people who are uninterested in hypermiling, or don't know about it - even if they aren't drastically better, financially speaking.

That's interesting that you sat down and did that cost/benefit work. I'm sure plenty of consumers would not have bothered!