Toyota's plug-in Prius is work in progress
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Test drives show the plug-in hybrid has potential
TOKYO -- I had to go to Japan to do it, but I finally got my hands on a plug-in hybrid.Not one of those hacked Priuses that after-market modifiers will produce in exchange for several thousand dollars and a canceled warranty. This was the real thing, built by Toyota at its research labs in Japan as part of its program to get a workable plug-in hybrid to market.
Toyota Motor Corp. sells more hybrids than any other carmaker, though that hasn't stopped some critics from questioning the company's commitment to advanced fuel-efficient powertrain systems.
So with the automotive media in town this week for the Tokyo Motor Show, Toyota perhaps decided it was opportune to demonstrate it has been spending time and money finding ways to replace the environmental disaster that is the internal combustion engine -- and has the sheet metal to prove it.
Which is how I came to be at a Toyota test track near the foot of Mt. Fuji, surrounded by engineers, interpreters, PR types and about half a dozen plug-in Priuses -- cars that may have a lot to say about how we get around in the future.
Hybrids such as the current-generation Prius use a traditional gasoline engine as their primary power source. A small, battery-powered electric motor powers the car for very short distances at low speeds and provides additional power at higher speeds. The payoff, in the Prius at least, is the highest miles-per-gallon rating of any mass-produced car in the U.S.
(Toyota and other automakers are working on plug-in hybrids with larger battery packs that would enable the car to travel several miles at highway speeds on electricity alone; the batteries would be recharged at night by plugging into a household outlet.)
Besides the bird decals and other eco-cute touches, the Priuses at Toyota's Higashi-Fuji test track looked a lot like the 2006 model that I drive from Glendale to work in downtown L.A. every day.
Other than the steering wheel being on the right, Japanese-style, the major difference in the interior was on the dashboard touch screen. In addition to the usual engine-motor-battery schematic, it displayed colored bars indicating whether the car was running on electricity alone or in hybrid mode. It also included a gauge that counted down the 10-kilometer, electric-only range.
The cars were equipped with nickel-metal hydride battery packs about twice the size of the ones in the current-generation Prius. The reason: to simulate the additional power Toyota hopes to get from lithium ion batteries, which are the leading choice among automakers right now for providing the power needed to move plug-in hybrids appreciable distances on electricity alone.
The Priuses at the test track could be operated in two modes: electric only or hybrid with an electric-only capability. (Unlike those in the U.S., Priuses marketed in Japan have an electric-only option, although the range is just a mile or so at very low speeds.)
The engineers warned me that the test cars were strictly developmental prototypes -- in other words, research vehicles not ready for dealer showrooms.
They weren't kidding. After strapping on my crash helmet and punching the familiar starter button, I hit the accelerator hard and almost threw the car out of electric-only operation.
OK, fine. When in hybrid mode, Toyota's plug-in system is designed to switch out of electric-only operation when it's confronted with a heavy demand for power -- maintaining speed up a steep hill, for example, or when dealing with a driver equipped with a crash helmet and a lead foot.
When I eased off the accelerator, the car didn't immediately switch back to electric power, even though the dashboard display said I had several miles of electric range left. I had to slow down to 20 kilometers per hour (you try to do metric conversions while careening around a test track) to return to electric-only.
That wasn't reassuring to someone thinking in terms of merging onto the 405 and then jamming across four lanes of traffic to the carpool lane, to enjoy seven miles or so of gasoline-free driving. In Southern California freeway traffic, slowing down to 20 kph to get the electric motor to kick back in isn't really an option.
The engineers assured me that it was no more than a software glitch, or maybe the catalytic converter didn't have time to warm up.
Whatever. A second test drive in a different test car resulted in the kind of torque-y acceleration electric motors are known for, speeding smoothly and quickly up to 50 mph or so, at which point an extra dose of throttle caused the gas engine to kick in -- as expected. And this time, almost as soon as the pressure was eased on the gas pedal, the car went back into electric-only operation as it was supposed to.
To get maximum electric-only efficiency, it seemed, the trick was to accelerate with a bit of restraint up to the electric motor's top speed of about 62 mph, thereby avoiding the sudden -- and admittedly satisfying -- burst of acceleration that can cause the gasoline engine to needlessly take charge.
Toyota won't talk mpg for the plug-in Prius, noting that it's tough to come up with a number that reflects both miles per gallon and miles per kilowatt. It also won't speculate on a sell-by date.
General Motors Corp., which is battling Toyota for the title of the world's largest automaker, has talked of a 40-mile all-electric range for its Chevy Volt, provided that researchers can develop more powerful and safer lithium ion batteries. GM says it could be ready for market in three years -- an aggressive projection that invites derision from other automakers, including Toyota.
Truth be told, I think I was a bit spoiled by the hydrogen fuel-cell Toyota Highlander I tried out just before the Prius test runs. The mid-size sport utility vehicle, powered solely by an electric motor, displayed very un-SUV-like oomph as I pushed it past 50 mph. It was smooth as silk and brimming with torque.
Too bad that there are only a few dozen in existence and that if you could actually buy one -- which you can't -- it would have a sticker price of about $1 million.
Maybe, as some critics like to say, hydrogen is the fuel of the future and always will be.
But for a few brief minutes in the shadow of Fujisan, the future felt awfully close at hand.
martin.zimmerman
@latimes.com
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