Depending on the model, these may also include a gear shift indicator, automatic air valve control, a high - efficiency rear differential, a map - regulated oil pump, a pressure / rev -
regulated electric fuel pump, a self - disconnecting air - conditioning compressor and tyres with reduced rolling resistance.
In contrast, a system in which
electric utilities are
regulated one way (say, cap - and - trade allowances), large industrial boilers another way, motor vehicles and their
fuels still another way, and various other industries and activites through other means or not at all leads to a complex system that is difficult and costly to administer, distorts the market, and allows businesses to game the system and find loopholes.