How Do Hybrid Cars Work?

Sri Lanka Removes Duty on Hybrid Cars

Sri Lanka has made electric and hybrid cars duty free, while value added tax and rates of depreciation allowed for used cars has also been increased, a budget for 2011 said.

Another tax, social responsibility levy has been removed and nation building tax reduced from 4.0 percent to 3.0 percent.

But a Treasury official said excise taxes have been raised to recoup revenue losses from other taxes.

Though the price of new cars may not come down, an official said the price of older car could come down.

Some commercial vehicles were already on a lower duty.

President Mahinda Rajapaksa said electric and hybrid vehicles will be completely freed from excise duties and value added tax to promote environmental friendly vehicles.

Motor homes will also be made duty free, according to the budget document.

Sri Lanka allows cars up to three and a half years old to be imported.

Now three year old cars will be depreciated to 60 percent compared to about 80 percent earlier. Cars three and half years old will be depreciated to 55 percent.

The budget speech said the depreciation tables will comply with World Trade Organization rules.

The government will also allow state workers and state corporation employees to import cars at a lower duty.

A provision that allowed people who paid taxes of more than 500,000 a year for three consecutive years to import cars at 25 percent duty has been removed in the budget.

Average fuel consumption per km

Here is a comparison

Model Model code CO2 emission (g/km) Average actual fuel consumption (km/l)
Allion DBA-NZT260 116 13.6
Axio DBA-NZE141 116 14.4
Vitz DBA-KSP90 103 15.1
Belta DBA-SCP92 116 15.6
Civic Hybrid DAA-FD3 81 18.3
Insight Hybrid DAA-ZE2 81 19.7
Fit Hybrid DAA-GP1 N/A 20.2
Prius hybrid (old shape) DAANHW20 82 21.6
Prius hybrid (new shape) DAA-ZVW30 76 23.2

How often do hybrid batteries need replacing?

nrle_phev_mockup1The hybrid battery packs are designed to last for the lifetime of the vehicle, somewhere between 150,000 and 200,000 miles, probably a whole lot longer. The warranty covers the batteries for between eight and 10 years, depending on the carmaker and the location.

Does hybrid vehicle battery need to be charged from out side? Hybrid vehicles batteries need not to be charged with electricity from outside. Battery is charged by the power supplied by the internal combustion engine while the vehicle is driven by it.

Does the hybrid cars need to change the battery?

Battery needs not to be replaced like a normal car battery unless it is damaged by an accident etc. Manufactures like Toyota and Honda say that battery is expected to last as long as the car last. However, any battery with aging will lose its capacity of holding electricity charge. Some experts predicts that the hybrid car battery will last at least 15 years though it is not official.

Quite and smooth run. Hybrid vehicles are quite and smooth while running because it combines two sources of power.

More km. Some hybrid vehicles run as twice km as what other normal petrol engine vehicles run. See below some details of hybrid vehicles available from Japan.

How Hybrids Work

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. If you are in a Toyota or Ford hybrid (and some GM hybrids), the internal combustion engine (ICE) gets cranked up, only to shut down again once it gets warmed up. This can happen quickly, or in colder weather, might take several minutes. At this point, the electric motor is now online, while the ICE remains dormant until needed.

The Toyota or Ford hybrid 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.

Unlike the Toyota and Ford hybrids, the engines in Honda’s hybrids warm up but don’t shut down completely until the first deceleration to a stop. This “auto stop” mode—conventional vehicles are wasting gas and spewing emissions during idle, while the hybrid is silent and gas-free—goes away when you lift your foot off the brake pedal, shift into gear, or depress the gas pedal.

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. Each time the Honda hybrid driver moves forward and them comes to stop—unless the car is warming up or the air conditioning is cranked—the ICE shuts off completely. Once again, the car becomes eerily silent (unless you are cranking the tunes).


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.

Digital Driveline

For your entire ride, the computer will be calculating when to let the gasoline engine do all the work and how much of a boost it needs from the electric motor. Because of the intermittent (but powerful) assist from the electric motor, the gasoline engine can achieve basically the same performance as a conventional car even when it has a smaller, more efficient size. Why put a high-horsepower, high-consumption engine into a car, when most drivers never drag race?

Meanwhile, back in the Toyota and Ford hybrids, 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.

Battery Charge and Discharge

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.
Wrap It All Up

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.

Hybrid-electric vehicles (HEVs) combine the benefits of gasoline engines and electric motors and can be configured to obtain different objectives, such as improved fuel economy, increased power, or additional auxiliary power for electronic devices and power tools.


Click here How Hybrids Work

Some of the advanced technologies typically used by hybrids include

Regenerative Braking. The electric motor applies resistance to the drivetrain causing the wheels to slow down. In return, the energy from the wheels turns the motor, which functions as a generator, converting energy normally wasted during coasting and braking into electricity, which is stored in a battery until needed by the electric motor.

Electric Motor Drive/Assist. The electric motor provides additional power to assist the engine in accelerating, passing, or hill climbing. This allows a smaller, more efficient engine to be used. In some vehicles, the motor alone provides power for low-speed driving conditions where internal combustion engines are least efficient.

Automatic Start/Shutoff. Automatically shuts off the engine when the vehicle comes to a stop and restarts it when the accelerator is pressed. This prevents wasted energy from idling.

For fuel economy information on these vehicles, please visit the Compare Side-by-Side section.