I'm not sure if we can safely assume the mpg will increase in a nice linear fashion as tread wears down. Any tire will increase in efficiency as the tread wears down so if much of the LRR characteristics of a specific tire is in the tread then as that tread wears out it will become more similar to lesser tires. That is the theory anyway. Given the Energy Saver A/S provides a mpg boost when new even compared to well worn tires I suspect they will always lead in efficiency, even when worn. I still cannot believe Michelin is going to stop producing them. I need to give them a call and confirm/complain if this is the case. This is the only tire I have ran that allows you to drive like the average Joe and still pull down high mpg numbers. Maybe it's too much of a niche tire? Oh, I forgot to add that the out of balance feeling is still here even at lower pressure. I'm going to bring it back to the shop and have them check it put.