It is not surprising, but the US was way ahead of any other countries across the world.
The models launched in the US under different manufacturers in Toyota in 2011 are:-
In Ford in 2011 are:-
Fusion, Escape, Mariner and Milan,
In Honda in 2011 are Insight and Civic.
In Nissan is Altima.
In Lexus is RX 450h, GS 450h, and LS 600h.
in GM are GMC, Chevrolet, and Tahoe.
In Cadillac are Saturn, Yukon, Sierra, Malibu, Escalade, and Silverado.
In Chrysler Dodge are Aspen and Durango.
The mechanical part of the Toyota Prius uses a set of planetary gears for realizing the continuously variable transmission. The carrier of the planetary gear is connected with the engine. Another important quality of the planetary gear set is to act as a power/torque splitting device.
The engine also shuts down during low-speed driving.
The technology is the same in the Camry hybrid, the Highlander Hybrid, and the Lexus brand hybrids. The only small difference is the addition of a third motor at the rear wheel for the Highlander and the Lexus hybrids.
In the case of the Honda Civic Hybrid, an electric motor is mounted in between the ICE (Internal combustion engine) and CVT(Continuously Variable Transmission). The mechanical function of the electric motor is to assist the engine during high power demand. Or the engine power is split during the low power demand.
Escape Hybrid is the first HEV in an SUV segment. The mechanics of realizing the CVT (continuously variable transmission) is the same concept as the Toyota.
The technology used by GM is to set to two different operating modes, a high-speed mode, and a low-speed mode. The two different operating modes are realized by using two separate planetary gear sets and two electric machines.
Source:- Alternative Fuels Data Center