Its not really a "hybrid" the same way that Toyota's vehicles are hybrid. The current hybrids have the following (I am over-simplifying this) algorithm:
- If at slow speed: use battery
- If at high speed or high acceleration, use gas
- If at medium speed with little or no acceleration, then use a little bit of both
However, the Volt uses the following algorithm:
- Use as much battery until almost dead
- If battery is just about dead, use gas
For short distances, it can give almost infinite MPG (which is why there has to be a special way to rate the MPG for this kind of vehicle). Toyota and Honda are going to use this second algorithm (called "EV Mode") in their new cars soon.