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There are a variety of advanced technologies currently available that improve fuel economy. The best fuel economy results from a combination of the following hybrid and advanced conventional vehicle technologies.
Download Fact Sheet: Hybrids and Other Advanced Fuel-Efficient Vehicle Technologies (pdf)
Hybrid-electric vehicles come in different configurations, but all have power trains that combine a traditional internal combustion engine with an electric motor and battery. All hybrids use regenerative braking to recover energy for the battery, and often employ other advanced conventional technologies such as efficient engines and advanced transmissions.
FULL HYBRIDS usually draw 25 to 50% of their peak power from their electric motor and are capable of electric-only driving. They utilize a variety of technologies and can improve fuel economy by more than 50% over conventional vehicles.
- Ford Escape and Mercury Mariner Hybrids
- GMC Yukon Chevrolet Tahoe, and Cadillac Escalade Hybrids
- Dodge Durango Hybrid
- GM/Allison Hybrid Electric Drive System
- Two-Mode Hybrid Transmissions
- Orion VII Hybrid Electric Buses
MILD HYBRIDS usually draw 15 to 25% of their peak power from their electric motor and are not capable of electric-only driving. They generally use an integrated starter-generator system that saves fuel by allowing the engine to shut down during idle and coasting. They usually have a 10 to 20% fuel economy improvement over conventional vehicles.
When compared to technologies like hybrid vehicles, advanced conventional technologies may appear to achieve only a modest fuel economy improvement. However, because of their high production volumes, these advanced conventional technologies have the potential to make a significant improvement on U.S. fuel economy.
VARIABLE VALVE TIMING (VVT) allows engines to vary the timing of their intake and exhaust valves, which improves efficiency and performance, reduces emissions and increases fuel economy by 4 to 8%.
- Pontiac Vibe
- Toyota Corolla
- Saturn Outlook
- Saturn Aura
- GMC Acadia
- Cadillac CTS, SRX and STS
- Cadillac XLR
- Ford F-150
- Pontiac Solstice and Saturn Sky
- Ford Explorer
- Chevrolet Cobalt
- Dodge Caliber
- Jeep Compass
- Jeep Patriot
- Chrysler Sebring
- GEMA's I-4 World Engines with VVT
- Ford's Modular V-8 Engine with VVT
- Ford's Duratec 35 Engine with VVT
- GM's Vortec Engine with VVT
- GM's Northstar Engine with VVT
- GM's Ecotec Engine with VVT
- Chrysler's Phoenix Engines with dual-VVT
CYLINDER DEACTIVATION allows engines to shut down some of their cylinders when they are not needed during normal driving conditions, improving engine efficiency and fuel economy by 8 to 20%.
- GMC Envoy and Chevrolet Trailblazer
- Jeep Grand Cherokee
- Dodge Durango
- GM's Vortec 5300 Engine
- GM's V-6 Engine with Cylinder Deactivation
- Chrysler's Phoenix Engines with Cylinder Deactivation
GASOLINE DIRECT INJECTION engines inject the fuel right into the combustion chamber of each cylinder causing a more complete burn. The engine also varies the amount of fuel that is injected, depending on the driving conditions. This technology improves fuel economy by up to 15%, decreases emissions, and increases power.
AUTOMATIC FIVE AND SIX-SPEED TRANSMISSIONS have five or six possible gear ratios instead of the conventional four. This allows for more efficiency during driving cycles, smoother acceleration, and a 4 to 8% increase in fuel economy.
- Ford Five Hundred, Freestyle and Mercury Montego
- Cadillac CTS, SRX and STS
- Toyota Corolla
- Saturn Outlook
- Saturn Aura
- GMC Acadia
- Jeep Grand Cherokee
- Ford Explorer
- DaimlerChrysler's Five-Speed Automatic
- Ford's Five Speed Automatic
- Ford's Six-Speed Automatic
- Ford/GM Six Speed Automatic
- GM's Six-Speed Automatic for rear-wheel-drive
- GM's Six-Speed Automatic for front-wheel-drive
CONTINUOUSLY VARIABLE TRANSMISSIONS (CVT) use a belt or chain pulley system instead of gears, allowing the transmission to apply to the most efficient ratio during every driving situation. They provide smoother acceleration and a 6 to 11% increase in fuel economy over a four-speed.
DUAL CLUTCH TRANSMISSIONS feature two independent gear sets with separate clutches. During shifts, the next gear is anticipated and selected, then one clutch is opened while the other is closed, allowing shifting without torque interuption. The technology is expected to provide a 5 to 10% increase in fuel economy.
LIGHTWEIGHT MATERIALS can reduce vehicle weight without sacrificing safety or durability. They include aluminum, plastic, magnesium, carbon fiber and metal matrix composites. Every 10% of weight eliminated from a vehicle's total weight improves fuel economy by approximately 7%.
ELECTRIC POWER STEERING systems run off power from a battery instead of the engine, thereby reducing engine load and improving fuel economy by up to 4%.
PARTIAL ZERO EMISSION VEHICLES (PZEV) achieve California's highest emission standard for gasoline vehicles by utilizing a combination of advanced technologies, including advanced fuel injectors, engine controllers, and catalysts that reduce start-up emissions and catch other pollutants.
CLEAN DIESELS utilize a combination of advanced engine technology, emission control technology and cleaner-burning diesel fuel to achieve the same emissions as standard gasoline vehicles. Although no current diesel vehicles achieve this, research continues and looks promising for future applications. Diesel vehicles get 20 to 35% higher fuel economy than gasoline vehicles but produce more harmful emissions. In 2007, the US government will mandate a nation-wide switch to low-sulfur fuel; this switch will help to improve the emissions of diesel vehicles.
Staff are organized as members of UAW Local 38.