How Green Is the Toyota Prius?

Dustin Hoffman, Larry David and other Hollywood celebrities tout the Toyota Prius as the real thing for the environmentally conscious.

They and many regular folks see the hybrid car as a step toward solving the problems of pollution and global warming. As a result, some go green with envy when a neighbor buys a Prius.

But is the Prius all it's cracked up to be? Let's take a look.

• Click here for's Patents and Innovation Center.

Toyota developed an innovative power train that combines an electric motor and a gasoline-fueled internal combustion engine. This enables the Prius to provide lower emissions and higher fuel economy than regular cars.

When accelerating, the electric motor and the internal-combustion engine work together, with the engine recharging the batteries. In bumper-to-bumper city traffic, the Prius alternates between the two power sources and sometimes runs on battery power alone.

A regenerative braking system converts energy usually lost as heat into electricity and uses that to further recharge the car's battery pack.

Green image

There also are other, intangible reasons for buying a Prius.

"If you buy a Prius, it shows you are the best liberal on the block," says Michael Omotoso, a senior manager of J.D. Power and Associates, the independent automotive-research firm. "If you buy it, your environmental image is instantly improved."

J.D. Power's latest forecast is that there will be some 354,000 hybrid car units sold in 2007, "a 39 percent increase from last year," Omotoso says.

Total reported hybrid sales this year have been 295,000, of which slightly more than half — 150,000 cars — were Priuses.

"Second place was the [hybrid] Camry at 47,000 units," Omotoso says.

The hybrid Camry uses a similar engine and battery but costs a few thousand dollars more than a Prius and looks just like a regular Camry.

The Prius, on the other hand, looks like nothing else on the road. It's got some cool technological features that you don't see in most vehicles, such as a continuously variable transmission and a space-age dashboard that looks like a video game.

Another feature is the nickel-metal hydride battery. There's no lead in that battery, no deadly toxin to leach into landfills when it's disposed of improperly.

The battery uses a hydrogen-absorbing alloy for its negative electrode, rather than cadmium. The positive electrode is made of nickel oxyhydroxide, giving it two to three times the capacity of a conventional battery.

Still, that kind of futuristic technology can have some practical drawbacks.

"Most independent mechanics won't touch a hybrid," says Kevin Harrison, a professor of environmental science at McDaniel College in Westminster, Md. "You have to go to the dealer."

More green to be more green

Harrison also points out that, as with organic food, you've got to spend a bit extra to go green.

"It does not make financial sense to buy a hybrid," Harrison says. "It would take years of ownership to recover the additional cost of buying a hybrid by saving money at the pump."

For example, the base price of a midsize Prius is about $21,500, Harrison points out, $7,000 more than that of the subcompact Honda Fit, which topped Consumer Reports' fuel-economy ratings for conventionally powered cars.

Using Consumer Reports' estimates, a Prius, which gets about 44 miles per gallon, will use about $960 in gasoline per year (at $3 per gallon for 14,000 miles), while a Fit, at 34 mpg for the stick-shift edition, will use about $1,250 — a savings for Prius owners of only $290.

At that rate, it would take nearly 25 years to make up the sticker-price difference.

"If you drive more than 14,000 miles in a year, you will recover the costs sooner," Harrison says. "If the price of gasoline goes up, you will also recover the costs sooner."

The Prius does better when matched up against a car slightly larger than itself — the Toyota Camry, which gets 24 mpg and costs about the same as a Prius for base editions.

The total yearly fuel cost for the Camry LE 4-cylinder model is $1,750, which means you'd be ahead almost $800 if you went with the Prius.

State governments and corporations, however, provide some financial incentives for buyers of hybrid cars.

In Connecticut, hybrid-car purchases are exempt from sales tax. In Illinois, the state government offers buyers a $1,000 tax credit. Companies such as Bank of America and Google also offer cash credits to employees. Not a bad benefit if you commute.

So is the Prius really a "green" car?

Yes. It gets terrific mileage for its size, and that means less pollution and fewer carbon-dioxide emissions per mile driven. Its batteries also are much less toxic when disposed of than conventional lead-acid automotive batteries.

But we'd like to see Toyota follow up on CEO Katsuaki Watanabe's desire to halve both the cost and the size of the Prius' engine and power train when it introduces the next generation of hybrids in late 2008 or 2009.

That'll make the car affordable for more consumers, and it will truly capitalize on Toyota's pledge to help save the planet.