The parallel full hybrid system developed by Porsche also offers "coasting" at higher speeds, a mode wherein the internal combustion engine is turned off and the electric motors use vehicle momentum to generate electricity that is stored in the lithium-ion battery.
Thus far, only a handful of folks internal to Valve have gone hands-on with TF2's VR Mode, and it's clear the hardware team is eager to get more feedback.
Now, it's true that amazing gains are being made in the efficiency of internal combustion engines, both gas and diesel: direct injection, cylinder deactivation, stop-start, eco-mode throttle mapping, to name a few of the recent applied technologies.