Hybrids come in different flavors:
- Parallel: Gas engine that drives the wheels but also has a secondary electric motor that can add a boost during acceleration.
- Serial: Gas engine connected to a generator and electric motors are driving the wheels.
- Plug-In-Hybrid: Has a larger battery pack and can run without starting the gas engine on shorter trips (10-50miles) but when the battery runs down, the gas engine starts up and it runs like a serial. Some of these don't do great in gas power mode.
But in terms of purchase, you have to look at your driving pattern.
- Find a standard gas engine car that is equivalent and look at the MPG.
- Find the MPG of the Hybrid.
Now estimate how many miles a year you will travel. Divide by the MPG and multiply by the cost of a gallon of gas...that's how much you will save per year. If that savings is enough, go hybrid but you may find that a comparable compact gas car getting 40-45mpg, going up to 50mpg may take a lot of miles to pay for itself.
Plug-In-Hybrid is a little more complicated. You have to estimate how many miles you typically drive in a day. Let's say you have a 40 mile commute and the car has a 25 mile range on battery (you recharge at night in your garage).
- You do the same calculation but assume 15miles per day as whatever the straight gas MPG is plus add in the cost of the KWH for the overnight charging for the other 25 miles.
- If the commute is only 10 miles, you will have almost no gas expense but don't forget the electric bill cost.
- If you commute 150 miles per day, the math is the same but you may find, it's not much better than a standard gas engine.
For your typical commuter, Plug-In-Hybrids are really going to take over in the next few years. Pure Battery EVs have a huge battery pack cost because they are trying to make them functional over hundreds of miles. A Plug-In-Hybrid can size the battery pack much smaller as it only needs to meet the typical commute (10-30miles typically) to get most miles under battery alone. That keeps them price competitive against gas engines while getting 70-95% of miles under battery power.