Enginer use to do this for hybrids, but quality control of the Chinese made parts got in the way. Between 1495-9 grand you can or could of got a 2-8 kilowatt phev kit for your hybrid vehicle. You got anywere from a 5-15 mpg boost under normal driving. By hypermiling you can easily double your mpg.
I purchases a 2 kilowatt system, then upgraded to a 4. My top was 103 a trip, 75 mpg the lowest before all that traffic from bridge repair on i95 when I had mines running.
The problem is most of the eco mods borders on the same mods the neighbor kid does to rice out his car. The main difference is yall do a kamel back where as the kid does a wing out of card board, coroplast, flashing, etc. The mods you do out of cardboard may become fiberglass, the kids, it just blows off.
