The fact is, hybrid vehicles vary enormously. It's not just that some are SUVs and some are cars. Their hybrid powertrains, themselves, can differ greatly in their design and programming. (Computer software has a lot to do with how a hybrid works.)
Right now, Toyota is the unchallenged hybrid leader. The Toyota Prius is the best selling hybrid by far, accounting for more than half of all the vehicles sold.
Toyota's "full hybrid" system is also used in Nissan's Altima Hybrid, and it's the same technology used in the Ford Escape and Mercury Mariner Hybrid SUVs.
General Motors, long seen as a laggard in hybrid technology, now has three types of hybrid systems on tap.
One, commonly called a "mild hybrid" system, is on the market now. Another, the "two-mode" hybrid system, will be introduced in the fall. A third "series hybrid" plug-in electric vehicle, is on the path to production, but no specific timetable is set.