Energy efficient technologies

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Energy efficient technologies

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Energy efficient technologies are available now! Many of the vehicles currently on display in dealer showrooms boast new performance-enhancing, fuel-saving technologies that can save you money.

(Number %) : average efficiency increase

Engine Technologies

Variable Valve Timing & Lift (5%) improve engine efficiency by optimizing the flow of fuel & air into the engine for various engine speeds.


Valves control the flow of air and fuel, into the cylinders and exhaust out of them. When and how long the valves open (timing) and how much the valves move (lift) both affect engine efficiency.

Optimum timing and lift settings are different for high and low engine speeds. Traditional designs, however, use fixed timing and lift settings, which are a compromise between the optimum for high and low speeds. VVT&L systems automatically alter timing and lift to the optimum settings for the engine speed.

Potential Efficiency Improvement: 5%
Savings Over Vehicle Lifetime: $1,400*

Cylinder Deactivation (7.5%) saves fuel by deactivating cylinders when they are not needed.


This technology merely deactives some of the engine’s cylinders when they are not needed. This temporarily turns a 8- or 6-cylinder engine into a 4- or 3-cylinder engine. This technology is not used on 4-cylinder engines since it would cause a noticeable decrease in engine smoothness.

Potential Efficiency Improvement: 7.5%
Savings Over Vehicle Lifetime: $2,000*

Turbochargers & Superchargers (7.5%) increase engine power, allowing manufacturers to downsize engines without sacrificing performance or to increase performance without lowering fuel economy.


Turbochargers and superchargers are fans that force compressed air into an engine’s cylinders. A turbocharger fan is powered by exhaust from the engine, while a supercharger fan is powered by the engine itself.

Both technologies allow more compressed air and fuel to be injected into the cylinders, generating extra power from each explosion. A turbocharged or supercharged engine produces more power than the same engine without the charging, allowing manufacturers to user smaller engines without sacrificing performance.

Potential Efficiency Improvement: 7.5%
Savings Over Vehicle Lifetime: $2,000*

Integrated Starter/Generator (ISG) Systems (8%) automatically turn the engine on/off when the vehicle is stopped to reduce fuel consumed during idling.

These systems automatically turn the engine off when the vehicle comes to a stop and restart it instantaneously when the accelerator is pressed so that fuel isn’t wasted for idling. In addition, regenerative braking is often used to convert mechanical energy lost in braking into electricity, which is stored in a battery and used to power the automatic starter.

Potential Efficiency Improvement: 8%
Savings Over Vehicle Lifetime: $2,200*

Direct Fuel Injection (11-13%) (w/ turbocharging or supercharging) delivers higher performance with lower fuel consumption.


In conventional multi-port fuel injection systems, fuel is injected into the port and mixed with air before the air-fuel mixture is pumped into the cylinder. In direct injection systems, fuel is injected directly into the cylinder so that the timing and shape of the fuel mist can be precisely controlled. This allows higher compression ratios and more efficient fuel intake, which deliver higher performance with lower fuel consumption.

Potential Efficiency Improvement: 12%
Savings Over Vehicle Lifetime: $3,200*

Transmission Technologies

Continuously Variable Transmissions (CVTs) (6%) have an infinite number of “gears”, providing seamless acceleration and improved fuel economy.


Most conventional transmission systems control the ratio between engine speed and wheel speed using a fixed number of metal gears.

Rather than using gears, the CVTs in currently available vehicles utilize a pair of variable-diameter pulleys connected by a belt or chain that can produce an infinite number of engine/wheel speed ratios.

This system has several advantages over conventional transmission designs:

– Seamless acceleration without the jerk or jolt from changing gears
– No frequent downshifting or “gear hunting” on hills
– Better fuel efficiency

Efficiency Improvement: 6%
Savings Over Vehicle Lifetime: $1,600*

Automated Manual Transmissions (AMTs) (7%) combine the efficiency of manual transmissions with the convenience of automatics (gears shift automatically).

Automated manual transmissions combine the best features of manual and automatic transmissions. Manual transmissions are lighter than conventional automatic transmissions and suffer fewer energy losses. However, most drivers prefer the convenience of an automatic.

AMT operates similarly to a manual transmission except that it does not require clutch actuation or shifting by the driver. Automatic shifting is controlled electronically (shift-by-wire) and performed by a hydraulic system or electric motor. In addition, technologies can be employed to make the shifting process smoother than conventional manual transmissions.

Efficiency Improvement: 7%
Savings Over Vehicle Lifetime: $1,900*