Get behind the driver’s seat of a hybrid car, and start it up. The first thing you notice is how much quieter it is than a conventional car. This can happen quickly, or in colder weather, might take several minutes.
At this point, the electric motor is now online, while the Internal Combustion Engine (ICE) remains dormant until needed. Toyota or Lexus hybrids will stay in this all-electric mode until about 15 mph—or if you accelerate very slowly, all the way up to about 30 mph. At low speeds, the careful driver is effectively operating an electric car, with no gas being burned, and no exhaust spewed from the tailpipe. Pretty cool. The more spirited driver will cause the ICE to kick in at lower speeds.
Depending on how hard you step on the gas pedal, the car’s computer will determine how much power to draw from the ICE, and how much power to pull from the car’s electric motor. The dashboard shows you exactly when the electric “assist” is working. When an extra boost of power is needed, a hybrid can pull additional energy from the batteries. At a stop, the stored energy can keep the vehicle functioning without burning any gasoline. When you step on the gas pedal, you are really controlling a pedal positioning device that tells the computer how fast you want to go, and the computer is once again making a lot of decisions about when to use the gas engine, when to go electric, or when to use a combination. The computer is, in fact, sending its signals to a gearbox, known as the power split device, which connects the gas engine and electric motors through a series of gears.
You probably understand the basics of how the gasoline engine is working, but where is the electric motor getting its juice? It’s actually drawing power from, or pumping power into, a set of nickel metal hydride batteries. The computer is performing a lot of magic by knowing when to reclaim excess energy when braking the wheels with the electric motor (which is now working like a generator). It also knows when to pass power from the battery to the electric motor for acceleration. The computer is monitoring the amount of charge in the batteries, making sure that they never charge more than 60 percent and never less than 40 percent of their capacity. In this way, automakers say, the batteries will last a couple hundred thousand miles.
Cover this technology with an aerodynamic frame and you’ve got yourself a major boost in fuel efficiency and a big-time reduction in poisonous, global-warming-causing tailpipe emissions. It’s not science fiction. It’s technology available today, in more than a dozen different sizes, shapes, and degrees of electric hybrid-ness.
