Until electric cars and their associated technologies (motors, batteries, controllers etc.) become mainstream, the internal combustion engine will need to be further refined in order to meet upcoming fuel economy requirements and current emissions regulations -- while still producing the power that consumers have come to expect. HCCI is one technology currently being developed to make these goals possible, while direct injection and turbocharging are simply becoming quite common.
We have brought up the idea of saving money on gas by riding a motorcycle or scooter a few times now, and invariably, we get comments which state that motorcycles are worse for the environment than cars. Is that true? Not necessarily. Exhaust emissions are calculated in parts per million, and more parts per million of harmful particles in the exhaust is bad. This is often cited in defense of cars, as motorcycles often have worse ratings in parts per million that autos. But, what about the differ