As the government hammers out how it will rate the fuel efficiency of hybrid-electric and all-electric vehicles, an Israeli company wants to make sure the U.S. gets it right.

The Environmental Protection Agency has a draft proposal for computing an efficiency rating using a “miles per gallon” scale but is not close to issuing a final ruling. It would be a rating buyers could use to compare various vehicles.

ETV Motors, a company that specializes in self-charging hybrid-electric propulsion systems for cars, has suggested in a letter to the EPA that the government consider a new multiple standard. CEO Dror Ben-David says ETV advocates a three-pronged rating for fuel efficiency: one number to show how far the car can go on a single plug-in battery charge, a second number to show how energy intensive the battery is, and a third for how much gasoline it consumes to drive a generator or the wheels when the battery runs out. Ben-David says the U.S. decision is important. “Most of the world looks at the United States as the standard provider and will adopt what the U.S. is doing.”

Even though no plug-in electric vehicles have yet hit the market in significant numbers, debate has begun over efficiency claims. Using an EPA draft proposal, General Motors has forecast that its plug-in Chevrolet Volt electric car will be rated at 230 mpg (it will go 40 miles per plug-in charge before the gas engine comes on to generate electricity), though the EPA cannot confirm that. Nissan, using different numbers from the Department of Energy, claims its Leaf plug-in car, an all-electric with no engine to burn gas, will get the equivalent of 367 mpg.

Says Ben-David, “A single number is not good enough. … It might be a bit misleading.”

Jim Kliesch, a senior engineer for the Union of Concerned Scientists, says there are a variety of other ways the government could set a standard to cover plug-in electrics, but no option is simple.

He says they could measure the car’s greenhouse gas emissions, a number that goes up when a vehicle consumes more gasoline or other fossil fuel. But that rating would also need to include how much carbon dioxide is emitted by power plants that generate electricity to recharge the car’s battery when it is plugged in.

And using an mpg rating formula may be misleading, Kliesch says, because people may not get that efficiency in the real world, depending on their usage patterns and how much or how little the onboard “range-extender” engine is needed.

“It’s really critical that the test procedure that’s decided on accurately reflects what people are going to experience,” he says. “Unfortunately, that’s easier said than done.”

Source: USA Today

Hybrids like Toyota’s Prius and plug-in vehicles such as the Chevrolet Volt run on systems other than purely gas-fired engines.

The systems, or powertrains, that drive the so-called greener cars use electricity generated by batteries and electric motors to either supplement or largely take the place of internal-combustion engines.

THE VOLT: The Chevrolet Volt, billed as a rechargeable electric car, gets most of its power from an electric motor and a battery pack with a 40-mile range. It also has a small internal-combustion engine that kicks in after the battery runs out of juice.

The Volt’s battery pack can be recharged from a standard home outlet.

General Motors Co. expects the Volt to get 230 mpg in the city, based on early tests using draft guidelines from the U.S. Environmental Protection Agency for calculating mileage of extended range electric vehicles.

GM officials say the fuel savings will at least partially offset the vehicle’s projected $40,000 price tag.

TRADITIONAL HYBRIDS: The Volt’s mileage could be a vast improvement over that of traditional hybrids, such as Toyota’s popular Prius, which combines an internal-combustion engine with a special hybrid battery that boosts fuel efficiency.

The newest version of the Prius starts at about $22,000 and gets an EPA estimated 51 mpg in the city and 48 mpg on the highway.

Other hybrid models use different forms of powertrain technology and don’t achieve the dramatic jump in mpg that the Prius does. For example, the Chevy Malibu hybrid, which starts at $25,555, gets up to 26 mpg in the city and 34 mpg on the highway.

By comparison, the purely gas-powered Malibu, priced at $21,605, gets up to 22 mpg in the city and 33 mpg on the highway.

With a nearly $4,000 premium on the hybrid model, consumers need to consider fuel prices, along with how much they plan to drive the vehicle, in deciding whether the extra cost is worth it.

ALL ELECTRIC: The Volt is expected to compete against high-end electric vehicles, such as the Tesla Roadster, which has a range of 224 miles, but also comes with a $100,000-plus price tag. Tesla is also working on an electric family sedan that will be priced considerably less.

If you’re looking for the very best fuel economy and insurance you can get, it’s a no-brainer that a hybrid car will have to be your choice, at least if you’re doing a lot of city driving, but even among hybrids there are varying levels of economy.

If the cars rated in the 2008 (and now 2009) model year seem somehow less impressive than their predecessors, or at least, less improved, remember that the EPA (Environmental Protection Agency) overhauled their ratings system in 2007, with 2008 models the first to be measured by the new standard, which is based on combined city and highway driving.

Nevertheless the top three cars of the year were all hybrids. Here’s a brief look at each of them:

• Toyota Prius: A five-seat lift-back with a plug-in version expected in the 2010 model year, the Prius has long been the poster-child of hybrid technology, despite the fact that it wasn’t actually the first to be sold. The old numbering system rates it at 48 mpg in the city and 45 mpg on the highway, thanks to its 4-cylinder, 1.5 liter gas engine and electric motor which work together to provide 110 horsepower. Currently, the only transmission available is a CVT (continuously variable transmission) system. No manual transmission is offered, or planned, at this time.
• Honda Civic Hybrid: Frequently compared to its direct competitor, the Prius, the Honda Civic Hybrid was actually the first such car to be marketed in the USA. Its gas engine is smaller the Prius’s, but more powerful (1.3 liters & 95 bhp) while its electronic assist motor is less powerful. The current version of the Civic Hybrid (2nd generation) is based on the 4th generation standard Civic.
• Toyota Camry Hybrid: While most other hybrids (Prius, Civic) are smaller cars, the Camry, which ranks as the third most fuel efficient hybrid, is on the larger side. This mid-sized sedan offers a roomy interior, the same clean, curves as the standard Camry, and a gas-electric powertrain system that produces something close to a V6 engine cranking out 187 hp. Its combined fuel economy is 35 mpg.

What about 2009?

For 2009, the first two cars on the most efficient list remain the same – Toyota Prius in the number one spot and Honda Civic Hybrid in number two, but the Toyota Camry Hybrid falls to sixth place, with the Nissan Altima Hybrid rounding out the top three instead. It has a combined fuel efficiency of 35 mpg for 2009, while the Camry is only rated at 33 mpg.

Does this mean prospective purchasers should only be looking at the Prius and Civic? Of course not  – unless they want the absolute best fuel efficiency available, and don’t mind getting it in a small package.

Source: Insurance Specialists