hybrid
trucks
Hybrid trucks are more efficient than regular internal combustion trucks in cities because the majority of fuel consumption occurs while accelerating and since trucks and buses have huge mass – the amount of fuel is increased proportionally. Under braking vehicles just disperse their kinetic energy, while it can be recuperated and stored. The heavier the vehicle – the more it benefits from this technology.
On the highway hybridization for trucks and other heavy vehicles benefits in another way: the internal combustion engine is not always working in its best, most desired range of RPMs and load (see the article about internal combustion engines here). Hybrid truck with electric drivetrain can use internal combustion engine as a generator at its most efficient mode and electric engine will provide most efficient performance using the least amount of energy possible not wasting a watt of extra power.