Many of the Pokmon within the Dream World will have abilities that the Pokmon you transfer over from Diamond, Pearl, Platinum, HeartGold & SoulSilver don't normally have, such as Vaporeon with Hydration and Glaceon with Ice Body. A few are also available in-game and others through events.
Hybrid cars have smaller, more efficient internal combustion engines than conventional vehicles because the electric motor provides additional power when needed. The smaller engines produce less pollution. Gasoline engines in hybrids automatically shut off when stopped and restart when the accelerator is pressed.
Some EVs and hybrids may be less harmful to the environment than some other types of car under some circumstances, but that's not the same as helping the environment. (question as answered : How do hybrid and electric cars help the environment?