Not worth it if you are looking to improve your mpg, but it is worth if you use it from time to time to "clean" the injection system (injectors, valves, combustion chamber, etc).
I say this because I used it twice and the result in mpg was not better than what I had with regular. I will use it from time to time though (for maintenance purpose).
White Platinum Metallic Tri-Coat
303A, 6-Speed SelectShift Automatic, 17" Aluminum wheels, Luxury Package,
Parking Technology, Navigation, Winter Package
Chevy Volt 2014, White Diamond, Luxury Package, S1