Comparing Green Car Technology Options
These days, there are several energy-efficient powertrains, but which automotive technology is most likely to replace the gas engine? Which will become your new ride?
GUIDE TO GREEN CARS, Summer 2012
By Todd Kaho
Efficient Gasoline Engines
Pros: Newer automotive technologies such as direct fuel injection and turbocharging increase power and gas mileage
Cons: Some of these advanced features can add cost and complexity; still dependent on foreign oil
Infrastructure: Gasoline easiest to find of any motor fuel
Electric Vehicles
Pros: Cheaper to operate than most other fuels; zero tailpipe emissions; convenient home charging; potential to get cleaner over time as more renewable energy (such as wind, solar) is added to our energy mix
Cons: Range anxiety, can’t realistically go cross-country; batteries are expensive
Infrastructure: About 6,000 public charging stations nationwide; growing steadily
Compressed Natural Gas
Pros: Domestically sourced fuel in abundant supply; cleanest emissions for an internal combustion engine; potential for home fueling and dual-fuel flexibility
Cons: High-pressure fuel tanks; dual-fuel vehicles require two separate fueling systems and limits passenger/cargo space
Infrastructure: About 1,000 fueling stations in the United States
Gasoline-Electric Hybrid
Pros: Now a well-refined green car technology; adaptable to many types of vehicles; great drivability and gas mileage; no need to plug in
Cons: Advanced batteries are still expensive and heavy; battery materials come from foreign countries; can’t plug in
Infrastructure: Gasoline available everywhere
Clean Diesel
Pros: 30 to 35 percent better fuel economy than gas; great performance thanks to generous torque; renewable biofuel potential; superb engine longevity
Cons: Petrodiesel dependent on foreign oil; more expensive to produce than gasoline engines; more complex emissions controls; debatable energy return on biofuels options
Infrastructure: Diesel fuel readily available
Propane
Pros: Good choice for fleet use; less expensive than gasoline; clean-burning; possible to convert gas vehicles to propane; domestically produced fuel
Cons: Misunderstood fuel; lower energy content than gasoline and lower mpg equivalency rating
Infrastructure: 2,500 fueling stations in the United States
Plug-In Hybrid Electric
Pros: Impressive fuel economy; ability to operate greater distances with zero tailpipe emissions; home charging adds convenience, greater all-electric range
Cons: Requires even larger and more expensive batteries; added weight
Infrastructure: About 6,000 public charging stations nationwide; growing steadily
Flex Fuel E85 Ethanol
Pros: Partially a domestically sourced fuel; low-cost upgrade on most vehicles
Cons: Up to 30 percent lower fuel economy than gasoline; misunderstood fuel that can damage vehicles not designed for its use
Infrastructure: 2,500 stations nationwide; best coverage in the Midwest
Hydrogen Fuel Cell
Pros: Electric drive provides good power; tailpipe emissions are water vapor and heat; hydrogen is the most abundant element on Earth
Cons: Hydrogen is currently expensive and power-intensive to produce; fueling stations concentrated in the Southwest
Infrastructure: Fewer than 100 public fueling stations in the United States