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Journalists Test Drive Toyota's PHEVs; Code Changes May Affect Converters
Oct 26, 2007 (From the CalCars-News archive)
This posting originally appeared at CalCars-News, our newsletter of breaking CalCars and plug-in hybrid news. View the original posting here.
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Of course, journalists are more inclined to write about their test-drives of "official" cars, even if they're prototypes, rather than after-market conversions. Despite the limitations they report, EVWorld, the LA Times and Popular Mechanics reporters had positive experiences.

The big news of these articles includes:

  • confirmation that Toyota has been testing its PHEVs for at least three years.
  • news that modifications in newer model Priuses may be harder for after-market converters, because the diagnostic codes used, among other purposes, for communications between the battery system and the hybrid computer, have gotten more complex. We haven't heard reports yet about Model Year 2008 Prius conversions -- but today (and whenever Toyota decides to build PHEVs), there will still be hundreds of thousands of 2004-2007 Priuses out there that can be "green-tuned."
  • discussions of the emissions issues if PHEVs require more cold-starts. It appears that both Toyota and after-market converters will be using the same solution : keeping the catalytic converter heated electrically.
  • Both the EVWorld and LA Times reports include descriptions of their fuel-cell car demos, found at the original URLs; the Popular Mechanics story says Toyota's next-generation Prius will arrive in 2009 and will plug in, which is not confirmed by anything we've heard recently; and the EVWorld report includes lively comments by readers at the URL (SUBSCRIBE!)

Driving Toyota's Plug-in Prius
Special report from Toyota's Higashi Fuji proving grounds on the
slopes of Mount Fuji.
By Bill Moore, EV World
Open Access Article Originally Published: October 25, 2007­article.cfm?storyid=1343

PHOTO CAPTION: According to senior engineering executives, Toyota's plug-in Prius has been in development for three years. Utilizing paired 1.3 kWh NiHM battery packs, it has an electric-only range of about 7 km. While far short of GM's announced goal of a 40-mile range for its Volt concept car, Toyota notes that the dozen confirmed vehicles it is experimenting with are on the road, not the drawing board.

Picture this. In the background is majestic Mount Fuji. In the foreground are six Priuses that represent the future of Toyota Motors and, most likely, the auto industry.

I and a handful of high-profile American automotive journalists are about to experience the ride of a lifetime: we're about to get behind the wheel of Toyota's internally developed plug-in hybrids.

For many of us who not only have been watching but also faming the flames for electric plug-in hybrids, it may seem that the big auto companies have only lately and reluctantly come to the dance. But as I am about to learn during our visit to Toyota's proving grounds, Japan's largest carmaker has been quietly experimenting with PHEV technology for much longer than many of us have imagined.

Our trip to Higashi Fuji started early in the morning with a 5 AM breakfast call, a walk to the near-by Tokyo central train station from which issues gleaming white bullet trains every few minutes and commuter trains every few seconds. As I am writing this, the trains are less than 100 meters from my 3rd floor room in the Four Seasons at Marunouchi. Gratefully, the sound proofing in the room is excellent.

Higashi Fuji is a one hour bullet train ride south of Tokyo, plus an hour-long bus ride that winds over narrow roads, through a string of Japanese towns and villages. Once at the Toyota proving grounds we must leave our cameras behind -- hence there are no photos of the plug-in Priuses we test drove or the FCHV (fuel cell hybrid vehicle) that was also on hand for us to experience.

After the pre-requisite company presentations, including a glitzy, but informative video, we piled onto a second bus -- thus insuring that no cameras would be present -- and wound our way through a maze of buildings and garages, eventually arriving at the center of one of the complex's two test tracks. There Toyota had set up two short driving courses, each adjacent to the other. The nearer course would be for the plug-in Prius drives, while the outer loop would be for the FCHV.

The company had set up a tent with folding chairs for the gathered journalists who report for the likes of the Wall Street Journal, Road and Track, LA Times, Edmunds, the New York Times... and of course EV World. But since the weather was fine and the six flower and bird-emblazoned Priuses beckoned, no one followed the script. Instead, we piled off the bus and made a bee-line to the neatly lined-up cars to check them over.

Apart from their curiously Zen-like applique of flowers morphing into birds atop pearlescent gray paint, the cars are your standard Japanese, right-hand drive models; albeit the computer display screen offers at least one new wrinkle that indicates one's driving performance in both EV and hybrid mode.

We had learned the previous day at Toyota City near Nagoya, that in order to experiment with the plug-in hybrid concept, company engineers had chosen to simply add a spare Prius NiMH battery to each vehicle, giving the car a total of 2.6 kWh of electric power capacity or enough to propel the car in electric-only mode between 6-7 km, an admittedly modest distance. Like the grassroots plug-in experimenters and converters in the U.S. and Europe, Toyota engineers also chose to locate the additional battery pack in the spare tire well below the rear cargo deck, a move that Toyota itself has criticized as being unsafe since it is outside the vehicle crush zone.

The other contradictory item of note is Toyota's assertion that the Priuses being converted by their owners are showing increased smog emissions over the standard, in-warranty vehicle because the catalytic converter doesn't have a chance to be warmed up by the engine once the car slips back into hybrid mode. It turns out that there is a vacuum bottle of sorts on the Prius that stores a heated fluid for up to three days and is used to pre-warm the converter, thus reducing cold start emissions. Presumably, it should also work on owner-converted models, assuming the plug-in converters have figured out how to hack that piece of the car's code, a topic I'll return to below.

Back on the track, Toyota organizers gradually regained control and gathered us around to brief us in the plans for the drive. We'd be paired together, two journalist per vehicle, and be required to wear helmets. Each of us would be given just one pass around the make-shift track in both the Prius and the FCEV. We could not exceed 70 km/hr.

I was assigned to car number two and offered the first drive. With Yoshikazu Tanaka seated next to me, I turned on the car and set-off in EV-only mode. Our assignment was to drive the first half of the course on battery only, followed by harder driving that engaged the IC engine. I found that I could maintain the equivalent of about 55 mph in EV mode, which the Prius has always been capable -- mechanically -- of achieving. However, for reasons of battery longevity, it is electronically prohibited from going above 34 mph in the standard model.

While critics have sneered at Toyota's admittedly modest claims for its PHEV technology, which falls well short of the electric-only range being pursued by General Motors -- 7-8 km versus 40 miles (64km), it likes to point out that it has, in fact, real working vehicles on the road. I counted a dozen during my visit to both Toyota City outside of Nagoya and the Higashi Fuji complex. How many operational Volts are there, they ask?

According to Yoshitaka Asakura, Toyota's hybrid program manager, the company began exploring the plug-in hybrid concept as long as three years ago, and from journalist test drives around the center on their sprawling test track, the company is still tweaking the system.

While my all-too-brief run was relatively uneventful, other journalists weren't as fortunate. Apparently the number 3 car had something of a software glitch. If the driver started off quickly, immediately engaging the IC engine, he would have to slow the car to around 20 mph for it to slip back into EV-only mode. The LA Times' Martin Zimmerman found this problematic, noting that it would make the car's electric-only feature useless on the mean streets -- and freeways -- of his adopted city. He wondered why the car didn't drop back into electric car mode more quickly after hard acceleration.

A couple other experienced automotive journalists also noted the same problem, so Mr. Asakura, who was overseeing the event, agreed to let them try a different car, which apparently did respond properly. The consensus among Toyota's engineering staff was that the hard acceleration at the start may have drained the battery just enough so the car needed a run in hybrid mode longer in order to recharge the pack.

Obviously, this is just one of the technical issues that must be resolved before commercialization and, no doubt, has led Toyota to adapt a cautious approach to plug-in technology. If after three years of experimentation, including intimate familiarity with their own computer control codes, the world leader in hybrid car technology is still learning, it suggests this may be a bit harder nut to crack than many of us had assumed.

On the question of those codes, I learned from Bill Reinert, Toyota USA's National Alternative Vehicles program manager, that from the 2007 model onward, it's going to be a lot harder for experimenters to hack into Toyota's control software. The catalyst for tightening up of what has been, up until now, pretty open code has to do with the implementation of OBD III (on-board diagnostics 3), a regulation from the EPA that requires new, more complex emissions data reporting aboard each car. While unrelated to the activities of the plug-in hackers, the change will make it harder for experimenters to read the vehicle's control codes.

The answer to the burning question of why Toyota is, after three years of testing, continuing to use NiMH batteries instead of lithium ion, which is what many of the grassroots converters are offering, appears to be directly related to the company's policy of utilizing its own internal resources, including battery technology, for advanced product development, in contrast to GM's partnering with outside venders like A123, JCS and Compact Power. Since its lithium ion batteries aren't presently up to its own stringent standards, it opted to utilize its well-understood NiMH system; and for testing purposes, this approach seems to be a pretty reasonable one. Besides, the software has been adapted to simulate lithium batteries, so when Toyota's own cells do become available, it can replace the NiMH without having to rewrite the code.

After the Prius run, I got to drive the latest iteration of the FCHV, a hydrogen fuel cell SUV based on the Highlander (Kluger in Japan). And as in the past, you cannot but be impressed by the transparency of this machine. Toyota may still be learning on the PHEV Prius, but it clearly has its act together on this vehicle, one of which recently traveled on a single fueling of hydrogen from Osaka to Tokyo, a distance of just under 350 miles.

[snip: section on fuel cell cars]

Toyota's plug-in Prius is work in progress Test drives show the plug-in hybrid has potential
By Martin Zimmerman, Los Angeles Times Staff Writer
October 24, 2007­business/­la-fi-hybrid24oct24,1,7206635.story

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.

[snip: section on fuel cell cars]

First Drive: 2009 Toyota Prius Plug-in Hybrid Prototype
By Ben Stewart­automotive/­new_cars/­4227944.html
Published on: October 22, 2007

TOKYO, JAPAN -- Toyota may be the first to market with a plug-in hybrid electric (PHEV) vehicle. Today, we were briefed on Toyota's future hybrid and alternative fuel plans. And while there was no official announcement by Yoshitaka Asakura, Project General Manager of Toyota's Hybrid Vehicle System Engineering Development Division, he mentioned that their plug-in development program was under way and that it may not wait for lithium-ion battery technology to mature.

'Toyota has the knowledge and experience with nickel metal hydride. And we have to use the battery we know best, in terms of overall performance,' said Asakura.

Toyota is using their proven nickel-metal hydride (NiMh) battery packs in prototype Prius PHEV's which we had an opportunity to drive at Toyota's Higashi-Fuji Technical Center about 45 minutes (by train) outside Tokyo. The prototype PHEV's use two current generation Prius battery packs sandwiched together with the charging system in-between. The packs are modified to deliver a greater ability to charge and discharge. This is, according to Asakura, so that they can get an accurate representation of how the more energy dense lithium ion pack will perform in production vehicles. In all likelihood, the first of those vehicles will be the next generation Prius. The prototype battery system weighs about 220 lbs. more than the current production Prius pack and intrudes into the trunk so that that's there's only room for about two medium size suitcases. A lithium ion pack would be much smaller and lighter--about the size of today's production battery pack.

Asakura said the prototypes can operate on electric power for a range of about 7 miles and can re-charge in three to four hours using a 110-vlot outlet. Under the hood is the current Prius's 1.5-liter inline four. The electric motor generates 50kW, which combined with the more powerful pack, allows the Prius prototype to reach 62 mph on electric-only power. Current cars can only hit about 25 mph before the gasoline engine cuts in.

Our drive in the prototype PHEV was brief, only four laps of a small course setup inside the test facility. But it was impressive. The hybrid system has an 'EV' mode and a more conventional 'hybrid' mode. In EV mode the vehicle can run on electric power longer and with a more aggressive throttle input than in the hybrid mode. With an eye on the energy flow meter (basically a reprogrammed and updated version of what's in the Prius now) we were able to accelerate up to approximately 50 mph and keep the car in electric mode all the way around the track. Like many owners do in the current Prius, we found ourselves playing the efficiency game of trying to keep the car in electric mode as long as possible. After two back-to-back laps, the monitor said we still had around 6 kilometers of battery life remaining. The most impressive part of the system was that it can take 1/4 to 1/2 throttle without engaging the gasoline engine. And that means for short 3 to 4 mile commutes, one could conceivably get to work and return home solely on electric power. The hybrid mode works much like the current car, engaging the internal combustion engine much sooner. This mode, it is presumed will be most applicable to long trips, when charging the battery isn't an option.

The next generation Prius, due around calendar year 2009, will almost certainly use a plug-in system. The car may launch as a normal hybrid and later, once the lithium ion battery technology is ready, switch to plug-in capability. Or, it may be a plug-in from the beginning using a large NiMh pack and switch to lithium ion later. We think the latter may be true because we've heard rumors that the vehicle architecture is being designed for both battery types.

Whichever route Toyota goes, it will need more hybrids on the road. They have publicly announced their goal is to sell 1-million hybrids each year beginning early next decade. And PHEV's are sure to make up a healthy portion of those vehicles.

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