They both receive a few (10-30) type-ins per month. However, the values of these domains are rather based on their future potential and not so much on their traffic at this stage :imho:
Future potential meaning that it is very likely that hybrid cars will replace gasoline cars as the most common vehicle in the near future.
Hybrid cars have been accepted as an intermediary solution to the current emissions problems that we face, as they offer lower emissions than gasoline cars.