Continuously variable transmission — the Prius does not use a typical CVT; Toyota calls it the Power Split Device. The electric motors and gas engine are connected to a planetary gear set which is always engaged, and there is no shifting.
The biggest drawback of having a hybrid car is that it can burn a hole in your pocket. Hybrid cars are comparatively expensive than a regular petrol car and can cost $5000 to $10000 more than a standard version. However, that extra amount can be offset with lower running costs and tax exemptions.