Nothing is "free", but remember you are comparing the self-sealing OEM tires which add the weight of the self-sealing goo. The non self-sealing version is lighter and may indeed have an efficiency advantage, but I believe that the Vredesteins are within a few percent of the Michelin OEMs. Also, don't forget when your replace a set of tires, you are changing from tread depth that has declined from 11/32 to 3/32. which reduces the diameter of the tire a half inch. You are getting fewer miles per rotation, but the speedometer won't know that. When you put on new tires, you can expect a few percent less just from the change in diameter and the weight of the lost tread. I have driven more than 6,000 miles on the Vredesteins, and typically take a 125 mile round trip weekly with it, so I have a good sense of efficiency. The weather and the use of heat or air conditioning are much bigger influences than the tire difference, but I think the safety upgrade with these tires is enourmous. That, and they are 2/3 the price of the OEMs! That pays for the compressor, tire plug kit, and tire sealer you need to have in the trunk.I find that last part to be a bit suspect. While I'm sure the Vredesteins are decently efficient, the Michelin Energy Saver A/S are in another class, even among low rolling resistance tires. Perhaps it's only a 5% difference in range, but to some people, that would be significant. Everything with tires is a trade off, so we don't just get "free" better handling, better water evacuation, and better cold weather characteristics.
That being said, I'm over 60,000 miles in my second set of OEM Michelin Energy Saver A/S (these are for the Gen 2 Volt), so I will be looking to replace them soon. I'll add the Vredestein Quatrac 5 to my list of consideration (I tend to do A LOT of research before purchasing tires).
Anyone else out there try these tires??? If I am wrong, would be good to get another point of view