[Owen]

People,

“Hybrids” HAVE GASOLINE ENGINES. If you check the Fuelly site, they quote the gas mileage results for 1000s of cars that people post, and average them together.

These cars have gasoline engines. They are almost always SMALL gasoline engines. If you check the gasoline mileage on a car WITHOUT a propulsion battery but with the same size gasoline engine you see numbers like 32 mpg. For a “hybrid” with a propulsion battery and that same size gasoline engine, you see numbers like 43 mpg.

This means the gas engine is pushing that car around 3/4 of the time.

You’re paying for the battery and charging / motor stuff and it’s only used 1/4 of the time.

This entire concept is a scam.

[ConservativeMind]

Not true. The motor assists the engine at all speeds, at least in the Ford Fusions.

[justlurking]

You’re paying for the battery and charging / motor stuff and it’s only used 1/4 of the time.

You are missing WHY it's only used "1/4 of the time".

The whole idea behind a hybrid is to use the electric motor in two cases:

1. When the engine is not needed (i.e below about 20 mph)
2. When supplemental power is needed for acceleration.

Obviously, the engine is shut off in the first case. But, most people don't realize that small bursts of acceleration occur all the time in normal city driving, and the electric motor can be engaged while the gasoline engine remains running at a constant (and efficient) speed.

So, where does the charging torque come from? There are three sources:

1. Regenerative braking -- when you use the brakes lightly, reverse torgue is applied and the electric motor/generator charges the battery.
2. When you lift the accelerator in a normal car, it slows down by running against engine compression. A hybrid applies a slight reverse torque, instead.
3. The engine runs most efficiently in certain power/RPM settings. When possible, the excess torque is used to charge the battery.

There is certainly a weight penalty imposed by the motor/generator and battery. But, the efficiency gained by the above more than makes up for it.

At current gasoline prices, it's difficult to make up the additional cost of a hybrid over the lifetime of the car. But, that hasn't always been true. And, it's difficult to predict how long it will remain true.