What is a hybrid car?

I've been looking into the hybrid car market for a while now, and I thought it might be time to put together some basic information. Wha...

I've been looking into the hybrid car market for a while now, and I thought it might be time to put together some basic information.

What is a Hybrid Car?
A hybrid car, by definition, is any car with multiple power sources. In most cases, there are only two power sources, but there can be more. A hybrid electric vehicle (HEV) comes about when an internal combustion engine (ICE) is mated with an electric power source (generator/motor) to move the car along. But there are other possibilities, including a fuel cell coupled with an electric motor, or a fuel cell mated to a gas engine, or you name it. For the most part, though, HEVs have become synonymous with the term hybrid.

Hybrid Car Features
Hybrid cars tend to come with several things. Regenerative braking helps restore power to the large battery packs necessary for the electric motor (more on that later). Some people claim that the regenerative braking makes the braking feel different.

Also, HEVs tend to shut down the gas engine when the car is stopped. Which means you won't hear the engine start when you turn the key (or push the button, or whatever starts your car up). Also, it can be disconcerting for some people to come to a stop sign and have the engine turn itself off. But, as soon as you start up, or when you attain a certain speed, the gas engine will turn itself back on again.

It's this stop-start feature, or in full hybrids the low speed electric motor only mode, that gives hybrid cars those strange EPA fuel economy ratings. For most ICE cars, the city mpg rating is lower than what the EPA rates the car for on the highway. In hybrids, it's reversed. This causes some people to argue that hybrids are best if you are going to do a lot of city driving. (Read more about the new EPA ratings and how they affect hybrid cars).

Benefits of Hybrid Cars
But why build a hybrid car in the first place? For an answer, check out this previous post on the pros and cons of hybrid cars. I'll summarize the benefits here.

The electric engine allows the gas engine to shut off when the car is stopped. That means you're not wasting gas when you're not moving. Also, electric engines are better suited for low speed engines, while gas engines are better suited for high speed situations. Hybrids allow you to optimize these operations. Fuel economy is higher (one of the more obvious benefits), but you also tend to pollute less. Pollution levels depend on the hybrid car, though, so be warned.

Mating the Two Engines in a Hybrid Car
The mating process between the two engines can be in series or in parallel. When the two powertrains are mated in series, only one of the motors controls the cars movement. The other one simply assists the first, dominant engine. This occurs most often in mild or assist hybrids. The Saturn Vue Green Line Belt Alternator System (BAS) is a good example. The concept vehicle named the Volt from GM is another good example of a series (but not a mild) hybrid.

When the hybrid engine is in parallel, both engines can propel the car alone or together. A good example would be Toyotas' Hybrid Synergy Drive (HSD). Capable of being propelled at low speeds by the electric motor, the gas engine takes over at higher speeds. This allows both engines to perform in their optimal situation.

Hybrid engines tend to be symbiotic. The gas engine powers the car and the electric motor by powering up the battery. Regenerative braking helps power up the battery pack, which powers the electric motor. The electric motor assists the gas engine or moves the car by itself. It's all quite complicated, but fun to watch happen in the nice graphical screens Toyota gives you in their hybrid cars.

Battery Packs in Hybrid Cars
Obviously, ICE are powered by the gasoline you buy when you fill up at a gas station. The electric motor/generator is powered by a large (and by large, I mean large and heavy) battery pack. Most hybrids on the road today have large Nickel-Metal Hydride (NiMH) battery packs somewhere near the trunk, or under the seats. (Read about the Lexus Hybrid battery pack).

Most automakers would like to see Lithium-Ion battery packs (you probably have a Li-Ion battery in your cell phone) which can store more energy. But as of right now, they are still too volatile/unreliable when placed in large packs for major carmakers to use. But that should be changing in the next few years. Both GM (with their Plug-In Saturn Vue) and Toyota (next generation Prius/ Hybrid Systems) believe the next generation of hybrids will come with Li-Ion battery packs.

These large battery packs take up a lot of room and are pretty heavy, which adversely affects the fuel economy and the storage space in most hybrid cars. These batteries get their power from regenerative braking and/or from the gas engine. Also, they are very expensive, costing thousands of dollars to replace. Which is why they are guaranteed for the life of the car (read you warranty, some states make automakers guarantee the battery for 100,000 miles).

There are some concerns when it comes to these high powered batteries and how good they are for the environment. But all hybrid batteries are set to be recycled (Toyota has a $200 bounty on each battery pack), and so unlike some lead batteries from conventional cars, they shouldn't end up in landfills.

Plug-In Hybrid Cars
Some groups are advocating the concept of a plug-in hybrid electric vehicle (PHEV). Plug-ins are capable of recharging the large battery packs by plugging into wall outlets. This brings together the best of two worlds (all electric and all gas engines). By plugging in at night, you get much higher fuel efficiency (on the order of 2 to 3 times what you get with current generation hybrids), because you are able to drive farther on the electric motor alone.

But, plugging in requires larger battery packs, which means Lithium-Ion, which isn't quite ready. Also, some claim that switching the pollution affects from gas engines to power plants isn't going to help much. Advocates claim it's easier to regulate the power companies.

The future of hybrid cars
In the past few years, hybrid car sales have taken off. Despite being only 1.5% percentage of the overall car sales market, hybrid car sales are still seeing phenomenal growth (a 28% increase over last year).

More discounts on hybrid cars are already being seen. The reasons I see for this are 1) federal tax credits are lapsing, 2) production costs are coming down, 3) there's more competition, 4) sales goals are still high, and getting higher, and 5) inventory is up.

Used hybrid car prices should start dropping. While they are still high, they are not as high as they used to be. Consumers don't have to wait three to six months to buy a new hybrid, so they won't be as willing to pay new car prices for a used hybrid car.

Tax credits from the federal government are starting to lapse. Toyota/Lexus, which sold about three out of every four hybrid cars last year, has already had it happen. Anyone who buys a Toyota hybrid car today is only eligible for half of what they could of gotten six months ago. As of March 1st, that is going to be cut in half again. Then, in September, it will be gone. Honda will hit the 60,000 car limit sometime this year, which means consumers of hybrids from Honda will start losing their tax credit at the beginning of next year.

Hot in Week

Popular

Archive

item