Hybrid highway

Ever since Stephen McGrogan picked up a screwdriver and turned his Toyota Prius into a stealth car, he's had problems. More accurately, others have had problems with him.

"I was in Orchard Supply going to pick up some stuff," he said, when an employee asked Mr. McGrogan to follow him through the warehouse. Mr. McGrogan flipped off the gas engine and rolled into the California chain's home improvement warehouse on what he calls "stealth mode," or silent battery power. "We were rolling along and I thought, 'This is going to bother him in a little while.' Sure enough, he spun around and stopped. I rolled up next to him, put the window down and said, 'It's electric.'"

While the hybrid gas-electric Toyota is sold in other countries with the capability of running off batteries with the engine fully off, Toyota disabled the function on Priuses sold in the United States. The move drove Mr. McGrogan, a Bay Area electrical engineer, and hundreds of other Prius owners to spend less than $100 for a kit, pick up a screwdriver, and rewire the car to unlock the function.

Mr. McGrogan is just impatient, that's all. And he believes he's on the upswing of a revolution. Hoping to inspire automakers while saving money at the gas pump, Mr. McGrogan and hundreds of other tinkering Californians are turning their Priuses into gas-sipping, post-mod hotrods on ice-or juice.

Spurred by meteoric gas prices that reached an average of $2.61 per gallon in August, other car owners are soon to be impatient like Mr. McGrogan, too. Hybrid sales in the United States have taken off. Last year, automakers sold just 85,000 hybrids to U.S. consumers. This year U.S. hybrid sales are expected to reach 215,000, according to a J.D. Power and Associates study.

Excitement about Toyota's Prius helped vault the Japanese automaker past Chrysler for the No. 3 spot in U.S. sales. In fact, Toyota says that by 2012, 25 percent of its cars sold will be hybrids. In light of impressive sales, Ford, Chrysler and even General Motors-once called road-kill on the hybrid highway-have all promised to dip more than a toe in the hybrid market. But it's not environmentalism or innovation that has brought Detroit's Big Three automakers fully into the hybrid car game. It's the bottom line-or perhaps more appropriately, survival instincts.

GM and DaimlerChrysler plan to develop jointly an advanced hybrid engine. GM plans to release its first hybrid SUV in 2007. Still, the best-selling automaker is cautious. "From a strict business proposition, this is not where we would make an investment," said Bob Lutz, current executive and one-time chairman of GM, at this summer's 2005 Detroit Auto Show. "It's not clear that you'll ever be able to recapture the cost of a hybrid in the pricing. But what we forgot in the equation was the emotional aspect of it."

Emotion is part of the drive for Mr. McGrogan, whose real problem now is that the 50 or so miles per gallon he can get in his Prius is no longer enough for him. Driving his Prius out of his neighborhood every morning in stealth mode is one thing, but how far could he get by adding more batteries? "I desperately want to plug that car in," Mr. McGrogan said. "All my driving could be done off an electrical outlet." That's the longing of many Prius enthusiasts, some of whom will spend thousands hot-wiring their cars with trunks full of batteries and a plug. They see the future car powered mainly by American coal and nuclear plants, not by foreign oil. In short, they see their autos as garage-sized electrical appliances.

Another Prius fan and electrical engineer, Ron Gremban, also of the Bay Area, took his modifications one step further. He installed a trunk full of batteries and a plug, and rigged his hybrid Prius to run on a mixture of 50 percent gas and 50 percent batteries. Like normal hybrids, the batteries recharge when the car brakes. But when Mr. Gremban gets home, he can also plug his Prius into an electrical outlet. Even with California's high energy prices, the kilowatt hours from the plug cost just a fraction of what it costs to create energy even in the Prius' efficient gas-fired engine.

If he doesn't wander too far from home, Mr. Gremban says he can get 80 miles per gallon. (Some plug-in hybrid pioneers claim to have gotten 250 mpg.) If he drives too far, he simply flips the car back into standard hybrid mode and maintains the car's normal efficiency. But fuel economy doesn't come cheaply. Mr. Gremban, who tinkered with his Prius for the grass-roots CalCars plug-in hybrid initiative, says he spent months of time and $3,000 before he got results.

Dave Hermance, Toyota's executive engineer for advanced technology vehicles, said Toyota discourages this sort of experimentation. He says hacking into the Prius and rewiring it will void part of the warranty. "You can be quite confident of that," Mr. Hermance said. "They'll end up getting what they deserve. We ought not have to warrant people hacking into the system."

He says other factors make the Prius a poor candidate for a plugged-in vehicle. In its electric-only mode, the engine can't handle speed of more than 35 mph. Much faster without the gas engine started, he says, and "the transmission will blow up."

Tinkerers with CalCars like Mr. Gremban hope they can prove the viability of plugged-in hybrids without waiting for car manufacturers to do it for them. "That's a different discussion," Mr. Hermance said. "But the reality is that today, any battery that can get you 20 miles-if you want to store enough energy to go 20 miles, you're talking about a very expensive battery that will have limited life." Just like batteries in laptops and cell phones, the charging and discharging of large battery packs in cars would shorten the battery system's lifespan. "And then you would have a huge replacement cost," he said. "Today's economics say we can't make a business case out of it. But we'll keep monitoring the technology."

Today's hybrids

Toyota Prius II

cost: $21,000; $25,000-$30,000 nicely equipped mpg: 47.9 engine: 1.5L 4 cylinder / 110 hp

The Prius is the most well-known hybrid, but getting one can be hard. Long waiting lists have kept some buyers waiting for months. Could it be the hottest hatchback ever?

Honda Accord Hybrid

cost: $30,000 mpg: 29.9 engine: 3L V6 / 255 hp

No one can call this Accord frumpy. It's the fastest family sedan on the market. It burns rubber without burning too much of the ozone layer.

Honda Civic Hybrid

cost: $20,000 mpg: 44.9 engine: 1.3L 4 cyl. / 93 hp

The economy of a hybrid without the disorientation of learning how to drive a Prius. Comes in a manual transmission which scores even better in fuel efficiency.

Honda Insight

cost: $19,000 mpg: 56.0 engine: 1L 3 cyl. / 71 hp

Cessna is to jumbo jet as Insight is to a typical American SUV. Even so, reviewers said Insight had enough get-up-and-go to get on the freeway. And the standard transmission version nets 65.2 mpg.

Ford Escape Hybrid (2-wheel drive)

cost: $27,400 mpg: 30.2 engine: 2.3L 4 cylinder

Last year, the Escape was all the rave. But low output (Ford only produced 20,000) and disappointing efficiency (many owners have reported low 20s for MPG) mean Toyota and Lexus have stolen Ford's thunder in the hybrid SUV market.

Toyota Highlander Hybrid (2-wheel drive)

cost: $33,000 mpg: 25.0 engine: 3.3L V6 / 268 hp

The hybrid assist makes the Highlander quicker than its gas-only counterpart. Lexus' RX 400h hybrid is basically the same hybrid engine in a different wrapper (and $10,000 extra cost).

Gas mileage estimates according to GreenHybrid.com's database of nearly 1,000 hybrid owners logging fuel efficiency over more than 10 million miles. As the hybrid community is fond of saying, your mileage may vary.