Expiring the Internal Combustion Engine Car

The US state of Washington has decided to ban sales of new cars with internal combustion engines (ICE, gasoline or diesel) by the year 2030. That is five years earlier than in the state of California.

There are two issues to overcome for a switch to battery electric vehicles (BEVs): supply and charging. Two common worries however will not stand in the way of BEVs replacing ICEs: cost and range. Let me explain.

Battery cost per kWh has been dropping for decades and this trend is expected to continue. THis is highly significant: Most parts of a BEV car other than the big battery cost either the same as in an ICE car or they’re cheaper. As a result, the cost of batteries will stop being a major obstacle to adoption of BEVs years before the end of the decade.

The same is true for range. Cheaper batteries mean BEVs with more capacity will become affordable. The higher the capacity, the more km of charge can be replenished in a given number of minutes. For example, a Nissan Leaf with a 40 kWH battery will fast-charge from 0 to 80% in 40 minutes. The Volkswagen ID.4 First Edition with an 82 kWh battery (of which 77 kWh are usable capacity) will go from 5% to 80% charge in 38 minutes, essentially double the charging speed (kWh added per minute) for a battery with twice the range. If you can add hundreds of km of range in the time it takes you to use the toilet and get a cup of coffee then BEVs will be just as viable for long distance trips as ICE cars.

By the middle of this decade there is likely to be a wealth of different battery electric vehicle models on the market, with even BEV laggards such as Toyota, Honda and Subaru having joined in. Production could increase to about 50% of new sales of several large makers (e.g. GM, VW). It will have to scale up further, with the necessary increase in battery production capacity, by the end of the decade to make this happen but it seems eminently doable. Right now, the major bottleneck to ramping up production is not lack of demand but limited availability of battery cells. Every big car maker getting into BEVs will have to build Gigafactories churning out battery packs, or team up with battery makers who make these huge investments.

The more BEV there will be on the road, the more the impact on the electric grid becomes an issue. If you have a car that can cover 300 km or more on a full battery and you can charge at home every night then most likely you will almost never have to seek out a charging station, unlike drivers of ICE cars who regularly will have to fill up at a gas station. BEVs parked in a driveway or garage with a nearby wall socket are much easier to accommodate than cars currently parking in the street or on parking lots, who will require capacity at paid public charging points, which are more likely to be used at daytime. The grid has plenty of capacity for off-peak charging (e.g. overnight), but if a lot of people want to do their charging at superchargers or other fast charging points, this could require an upgrade in generating and transmission capacity to cover a higher daytime peak load. Vehicle to grid technology would help to make this more manageable, as cars sitting idle in a driveway could provide spare power for the few cars doing the odd long distance trip.

In any case, I see a date roughly around 2030 as the Goldilocks target for a phase-out of ICE-powered new cars. For high income countries this goal is neither too unambitious nor too unrealistically aggressive. Japan’s goal by contrast for a phase-out by the mid-2030s that still allows hybrid ICEs like the Toyota Prius after that date is quite unambitious. By setting the bar that low, prime minister Suga pleases Toyota, as expected, allowing it to keep selling dated technology in Japan that they will no longer be able to sell elsewhere. That puts Japan in the company of developing countries, which will most likely continue using ICE cars exported from rich countries for years to come.

The sooner rich countries switch to BEVs, the shorter the long tail of CO2-emitting ICE cars still running in poorer countries will be.

Test-driving a Tesla Model 3 in Tokyo

Recently my son Shintaro and I went to the Tesla showroom in Aoyama, Tokyo to take a Tesla Model 3 for a test drive. I wanted to see for myself how this electric vehicle compared to my almost 12 year old Prius hybrid and to be able to compare it to future EVs from other brands that we may eventually consider.

I’d noticed an increasing number of Teslas around Tokyo, though they’re still far rarer than around the San Francisco bay area. Given that much of Japan is densely populated, range anxiety (an often cited reason for slow electrification) should be less of an issue here compared to the US, particularly with cars that already have over 400 km of range.

I love the practicality of the rear hatch of my Prius that allows me to carry two road bikes without disassembly by simply folding the rear seats. The Tesla Model 3 has a much less accessible trunk, which pretty much rules it out for me. The Model Y will be more practical, but is also even bigger. Apparently it won’t be available in Japan until a year or two after it starts shipping in the US this month (March 2020).

Tesla’s models are quite large by Japanese standards, with implications for parking and for driving on narrow back streets. For example, these are the dimensions of the Tesla Model 3 vs. the current generation Toyota Prius (XW50):

Length: 4690 / 4570 (+120 mm)
Width: 1850 / 1760 (+90 mm)
Height: 1440 / 1470 (-30 mm)

Exact numbers for the Model Y aren’t available yet, but it’s expected to be about the same width but about 1600 mm tall (160 mm taller than the Prius).

The test drive was an unusual experience by Japanese standards. Somebody had mentioned that the dealer experience with Tesla is more like visiting an Apple store than a traditional dealer showroom. I’d say the difference was even greater.

Customer service expectations in Japan are incredibly high and that is probably one factor for Tesla’s relatively sluggish sales here, see a recent Japan Times article.

Shintaro had tried to make the reservation online and was promised a callback within 48 hours, but that never happened so he had to call again to fix up an appointment.

Even when I take my Prius to an oil change at a local gas station, I’ll be served a cup of coffee while I wait. By contrast, when we visited the Tesla showroom to evaluate a JPY 5,100,000 (USD 48,000) car, all we received was a business card of the sales person. They don’t even give you paper brochures. You can look it all up on the website, right?

Before the test drive they took photo copies of our drivers licenses. We were instructed not to take any pictures and to follow the rules of the road. We would be liable for any incidental damage to the car during the test drive. Then we got into the car parked by the roadside outside the showroom, first as passengers, then later taking turns driving it around Akasaka.

I liked the seats, which were nice and firm. The acceleration when you put your foot down is amazing. It feels like a big car but with enough power for its weight. Getting back into the Prius later, it felt quite light by comparison, by which I don’t mean acceleration but it simply feels like a lot less metal being moved around. It tips the scales at about 280 kg less than the base Model 3 (1335 kg vs. 1612 kg).

Some of the controls took some getting used to, such as the lever action of the indicator stalk (which is on the left unlike in Japanese cars) or putting the car into park or into drive with the right stalk. Much of the demonstration involved showing the use of the center screen and its user interface. Many of the functions of the car, such as the electrically assisted steering or the regenerative breaking can be tweaked there, to change the feel of the car.

Headroom in the Tesla was good but personally I don’t much care for the glass roof. In a roll-over accident I would feel safer with a steel roof, but maybe those are not so likely with the low center of gravity afforded by the floor-based battery. The car interior felt overheated when we got into it and no fan was blowing, but I only asked about fan control towards the end of my driving portion. In any other car I would have easily figured it out on my own.

Checking out the trunk and the “frunk” (front trunk) after we got out of the car, the limited access for bulky luggage from the rear was quite a contrast to our Prius, in which we regularly move large items from a DIY center or bicycles for cycling tours far from Tokyo. The Model Y will address that, but it’s also 160 mm taller than the Prius on top of being 90 mm wider like the Model 3. That’s more air resistance and more kWh used to overcome it. That’s one thing I love about the Prius, it offers all this interior space despite being compact and efficient on the outside. 🙂

The width would already make a Model 3 or Model Y a very tight fit in our driveway. We would also have to figure out if there’s enough clearance around the car to plug in the charging cable for overnight charging.

In summary, Tesla’s range of cars is not an easy sell for me as a Japanese customer. While they have great technology, some of the design choices are not a good fit for Japan and the customer experience when dealing with the company (especially given the price range) will not match a lot of cultural expectations.

UPDATE (2020-03-19):

Size information has finally been released for the Model Y. These are the exterior dimensions compared to my current Prius:

Length: 4751 / 4570 (+181 mm)
Width: 1921 / 1760 (+161 mm)
Height: 1624 / 1470 (+154 mm)

Given the width and height it looks like it has roughly 20% more frontal area than the Prius which will impact its air resistance and hence energy usage at freeway speeds.

Toyota is yielding the future to Tesla and other EV makers

In October 2019, Toyota along with General Motors and Fiat Chrysler sided with the Trump administration in its effort to strip the state of California of its ability to set tighter vehicle emission standards than set by the Federal government. In July 2019, several other car makers including Ford, Honda and Volkswagen had sided with California.

This seemed a very odd move for a company whose iconic Prius hybrid was once seen as a way for people ranging from middle class families to Hollywood stars to show their green credentials. Toyota seems on the wrong side of history now.

I also drive a Prius which I bought almost 12 years ago. When it came out, it was way ahead of everything else: Three times as fuel efficient but more spacious and more reliable than my Audi. It wowed me when I first saw one and later when I first test-drove a friend’s. As an engineer I appreciated the clever technology behind it and as a family man I could rely on it for affordable transport.

However, if I were to buy a car now, I’d have a hard time making up my mind. If Tesla had designed its Model 3 as a mid-size hatchback (like the Prius) instead of giving it a trunk, the choice would be easy. Tesla seems set to address that criticism with its forthcoming Model Y, which will be like a slightly larger hatchback version of the Model 3. If Toyota had redesigned its Prius as a battery electric vehicle (BEV) with at least 300 km of range, the choice would have been even easier. The problem is, Toyota isn’t going to do that and I think I understand why.

I have talked to Toyota dealer sales representatives who came to sell me a new Toyota and when I mentioned about electric vehicles, they kept telling me the time wasn’t ripe for that yet, that infrastructure was too spotty and range too short. I would be better off getting another hybrid as the next car. And Toyota has many hybrid models.

This is precisely the problem: Toyota kept enhancing the hybrid drivetrain of the Prius, improving fuel economy with every new version. Now many different models, from the Toyota Aqua / Prius C to the Corolla Hybrid to the JPN Taxi basically all use the same family of engines, gearbox, battery, inverter and other electric systems. This has kept development costs low and maximized economic gain from the numerous patents that Toyota has received for the Prius.

Meanwhile, Tesla appeared on the scene as a complete outsider and took a radically different approach. By going for an all-electric drivetrain they don’t need an Atkinson-cycle internal combustion engine (ICE), an electrically controlled planetary gear transmission and many other mechanical parts that make the Prius family unique. They just need a bodyshell, an electric motor/generator, inverter and battery. For the first models the battery was basically built up from the exact same “18650” cells that power laptops and the bodyshell for the Tesla Roadster was bought in from Lotus.

Batteries for the automotive market are made by specialized suppliers such as Panasonic and LG instead of being based on in-house designs and intellectual property such as ICEs or gearboxes. Motor/generators and inverters are much simpler and less proprietary than ICEs. The basic technology for inverters used in BEVs and the electric part of hybrid drivetrains has been around since before the 1960s. Toyota engineers got the inspiration from the electrical systems used in bullet trains (shinkansen) that launched before the 1964 Tokyo Olympics.

If current owners of conventional or diesel cars replace their aging vehicles with hybrids then Toyota and its stable of Prius and cousins will do very well. If people however take a good look at the ecological realities of the 2020s and beyond, they will see that the sooner we can stop pumping more CO2 into the atmosphere, the less catastrophic our future will be on this planet. If we still drive cars, they will have to run on renewable energy sources, which hybrids can’t do (except plug-in hybrids for relatively short distances).

This raises a second issue: Toyota has been betting on hydrogen as the fuel of the future. Its Toyota Mirai runs on compressed hydrogen (H2), which is converted into electricity in an on-board fuel cell. This gives it a range of about 500 km between refuelling.

If Toyota were to sell BEVs with ranges of 300-450 km, this would undermine the rationale for hydrogen cars which need a completely new infrastructure for refuelling. Each H2 station costs millions of dollars and the fuel is expensive.

The most economical way of making hydrogen is from natural gas or coal, which releases greenhouse gases. Though one could make hydrogen through electrolysis (splitting water into hydrogen and oxygen using electricity), because of inefficiencies inherent in this process, this would actually consume about three times more renewable electricity than covering the same distance by charging/discharging a battery. This is why hydrogen will ultimately remain an automotive dead end.

What hydrogen technology basically gives Toyota is a political fig leaf: They can claim to have a path into a carbon-free future that does not rely on batteries (like Tesla and others). Using that fig leaf they think they can keep selling cars that burn gasoline, in California and elsewhere. Perhaps they can hold off moving beyond hybrids for years and years to come. If they can keep selling what they’ve got they may make healthy profits in the short term, but for the sake of the planet I hope this plan won’t work.

I’ve seen this movie before. In the 1990s Sony launched its MiniDisc (MD) player as a replacement for analog audio tapes and recordable alternative to digital Compact Discs (CDs). Then, in the late 1990s MP3 and flash memory came along: smaller, cheaper, more simple. The whole strategy fell apart. Sony could have accepted that MP3 was a superior solution, but that would have then put them on a level with every other audio consumer product maker. Their patents on MD would have become worthless. So they struggled on with trying to promote MD until they eventually had to kill it. From the inventor of the iconic Sony Walkman that had created a whole new market and sold the brand name to billions of consumers, Sony turned into a company that had lost its way. It let newcomers such as Apple with its iPod (which soon morphed into the iPhone) take over the market and consumer mindshare. The rest is history.

So if you’re listening, Toyota: Please build a car as spacious, practical and reliable as the Prius, but without a hybrid drivetrain that still releases CO2 with every km driven. Make it a no compromise battery electric vehicle. Support vehicle-to-grid technology, in which parked cars have an important role to play for stabilizing the electrical grid. Instead of working with fossil fuel companies to turn fossil fuel into hydrogen for thousands of yet to be built H2 filling stations, support expanding renewable power production from solar, offshore and onshore wind, geothermal and large scale storage, which is what we will need for a carbon-neutral future.

Meanwhile, when the time comes to replace my 12 year old car I will look at all the battery electric hatchbacks on the market then. If there is no Toyota amongst them then my next car will not be a Toyota. It’s as simple as that.

Dekopon, Cherry Blossoms and Some Rain: BRM330 200 Km in West Izu

The dekopon season will be coming to an end soon, but to compensate the shorts-and-short-sleeves season has started! I enjoyed both on Saturday, buying local dekopon (4 big juicy ones for 300 yen) in West Izu. The roadside stand worked on the honour principle: I dropped my coins into the collection box and took one bag of fruits.

I was the only rider in shorts at the start of the 2019BRM330 200 km brevet in Mishima, out of 13 who had shown up, out of 30 who had signed up, the others having been put off by a weather forecast that predicted a high chance of rain in the evening.

I drove to Mishima on Friday night with the Elephant Bikes NFE in the back of my Prius and parked the car in a coin parking lot (700 yen for 24h). I stayed at the Toyoko Inn, which was also going to be the goal of the 203 km ride which started at Mishima station. There were 2 courses, the hilly Matsuzaki course and the insanely hilly Darumayama course. I had tried and DNFed the latter in 2017, so it was Matsuzaki again for me.

Before the 08:00 start I loaded up the course on my GPS unit, but hit an unexpected snag when it reported a file system error that required a factory reset of the unit, meaning I’d lose my stored breadcrumb trail for navigation that I normally use. So I had little alternative but using my phone and the paper cue sheets for navigation. However, I had not brought my usual plastic cover for the phone to protect it on the handle bars in case of rain, nor had I weather proofed the cue sheets. The map bag of my front bag is not totally waterproof.

I used RWGPS to load the course and map and it gave me verbal directions in English throughout the ride. I kept the phone connected to a 10,000 mAh USB battery in my front bag until the goal. I have two USB batteries and two phones. There’s always a plan B and sometimes a plan C! 🙂

When the rain started to come down on the way back near Toi, I covered the phone with a plastic shower cap from a hotel stay which I secured it with rubber bands. I always keep one shower cap in the front bag as an emergency cover for the leather saddle or whatever. When my wet fingers made the touch screen difficult to operate, I used spare dry socks that I also kept in the same bag to wipe the screen dry again.

During a brevet on February 10, 2019 organized by Audax Kinki, a participant was sadly hit from behind and killed by a car in a tunnel. Brevet participants are required to wear reflective vests throughout the ride, but sometimes they wear a backpack which could partly obscure the reflective vest. Thus we were asked to wear the vest on top of any backpack. I actually brought two reflective vests, one to wear and one for my light string backpack (for spare clothes) to “wear”, which made getting changed quicker. I had bought the second at a brevet reception when I had forgotten the original one at home.

Most of the starter group did not spread out much until we turned the NW corner of Izu and the bigger climbs started. I took some pictures of the others and the scenery, but it was too hazy to see anything of Mt Fuji or even much of the mainland coast of Shizuoka on the other side of the bay. Mt Fuji remained totally hidden for the entire day.

As it got warmer towards noon I started fading a bit. I would have been really uncomfortable in long pants and thermal jacket. I was now riding on my own but comfortable in the knowledge that I was 50 minutes ahead of minimum pace at that point, which should normally ensure that I would complete the ride under the time limit.

There were a fair number of cherry trees, but most of them weren’t in full bloom yet, many quite sparse at the top still, so I didn’t take too many pictures of them.

There were only two timed controls on this course between the start and the goal, with 161 km in between. Near the southernmost point of the ride there was a photo check: We had to take a picture of a viewing platform on a mountain road together with our brevet card to prove we passed there. I climbed the mountain road together with a young couple. They had already suffered a puncture in NW Izu that had cost them time, while I frequently stopped for pictures.

From there I enjoyed a long descent to Kumomi Onsen. I had visited there in December and then climbed Mt Eboshi, which offers a breathtaking scenery of the coast. We passed Iwachi Onsen, where I had often visited by car when our children were still little.

I was trying to make it to near Heda village by sunset, where a staff member was taking pictures of all of us as we passed, but my own pictures took priority. At the last conbini in Toi before the wilderness it started raining and I put on my rain gear. On the descents I had to be a lot more careful. The wet asphalt soaked up all the light.

The rain became quite intense and I couldn’t help thinking of the 17 non-starters who had listened to the weather forecast… but with my time buffer I expected I’d still make it in time, unless I had bad navigation problems in the last 20 km. The phone became difficult to use when its touch screen got wet. Once, the RWGPS app somehow ended up back on the route selection and I had to restart the Navigation, which seemed to have cost me my downloaded maps 🙁 Now I could only use the turn by turn instructions to follow the course, but no map view. Fortunately, those turn by turn instructions worked flawlessly, even if the sound volume wasn’t always high enough to be clearly audible. Worst case I had to check the screen. Twice I went off-course but it soon let me know and it recovered when I backtracked to the wrong turn.

After more than 3 hours of riding in the dark I finally got close to Mishima station. When I stopped at the traffic light across from the Toyoko Inn, a staff member waved at me and handed me a note with the finishing time after I crossed. It was 21:19, only 11 minutes under the cut-off time. At the goal reception I presented my brevet card, the receipts from PC1 and PC2 (both 7-11 stores) and showed a photograph of the viewing platform. I had successfully completed! The young couple also made it. They arrived a mere 2 minutes before closing time. Another cyclist who had punctured on the last part of the ride in the rain was over the time limit.

On the drive back to Tokyo I stopped twice at Tomei expressway service areas for some rest, as I was too sleepy. When I got home I unloaded the car, took a shower and went to bed at 02:00. Two more weekends before the 360+ km Fleche ride for which I’m preparing.

Good bye Audi, welcome Prius!

Only about 6% of cars sold in Japan are foreign makes (mostly German), but Kanagawa prefecture and its capital Yokohama have one of the highest rates of import cars in Japan. Yokohama is one of the two major ports (the other is Kobe), it has a relatively long history of exposure to Western influences and on average is relatively wealthy. Even so, the street where I live in a middle class neighbourhood is unusual for actually having more foreign cars than Japanese ones.

Until very recently the count was as follows:

  • Mercedes Benz: 4
  • BMW: 3
  • Volvo: 2
  • Audi: 1
  • Porsche: 1
  • Toyota, Nissan and Honda: 4

Since then the numbers changed because I sold my Audi A4 and bought a Toyota Prius. Who knows what’s going to happen when the only German in a street in Japan where German cars outnumber Japanese cars trades in his German car for a Japanese one? 😉 It’s going to be interesting.

The first time my wife and I washed it in front of our garage, neighbours from two houses came over to take a look at it and to talk about it. One couple, who have a BMW X5 were very curious. They explained they only get about 6 km per litre (17 litres per 100 km) and were thinking about what to replace their car with. The other, who drives a Volvo came up as soon as she saw her neighbours across the street talk to us. Afterwards, the wife of the BMW driver said: “Minna eko ni shimashô!” (“Let’s all go green!”)

I expect we will see more hybrids in our street soon.

I’ve driven Audis (or Volkswagens based on Audi designs, such as the VW Passat) since I got my first car in 1982. Generally I have been very happy with them, especially an Audi coupe quattro 20V I had from 1989 to 1994. The latest Audi A4 2.4 however that I bought in 2000 was heavier and seemed not as well made as its predecessors.

The A4 was fun to drive when I bought it second hand with only 3000 km on the clock, but its V6 engine was never anywhere near as fuel efficient as my previous five cylinder engined Audis, nor was it quite as reliable.

After spending more than $2500 on repairs in the final year alone while consistently getting only about 320 km of range out of a 53 litre refill of premium unleaded (98 octane RON), I was starting to worry for the future of that car.

Even allowing for the fact that most of our trips are short runs to the station or to shops, usually less than 10 km total, with the engine starting from cold much of the time, that 16-17 l per 100 km (6 km/l) that I was getting was simply way too much. The best I’d seen was around 12 l per 100 km (8 km/l) on long highway runs on a ski trip.

Then one day last winter I took my daughter to an entrance exam at a junior high school. As I was waiting near the school, a Toyota Prius rode past me in “stealth mode”, running only on its batteries without any engine noise. It was almost as quiet as a bicycle. My curiosity about this car was awakened.

I had heard various rumours about the Prius, such as about limited battery life and started to check out the facts. I found the batteries did not need replacing every couple years and were expected to last as long as the rest of the car.

The more I read, the more I was fascinated how much thought the Toyota engineers had put into this car and how methodical they had been about making it work in real life. The Prius has been around in Japan since 1997, even though relatively few of that first generation were sold until 2000, when the second generation came out, which went into export markets too. Even before the Prius, Toyota had already been gathering experience with the RAV4 EV, a plug-in electric. The 1.5 litre engine in the Prius is a close cousin of the identical sized engine in the Yaris / Vitz / Platz ranges, but using the more efficient Atkinson cycle instead of the Otto cycle. Its peak efficiency is 34%, better than some diesels. By giving up on peak power and peak torque (which instead are provided via the battery and electric motors), the engine can be much more efficient.

Later in February my Audi needed more repairs and this time I had a Toyota Corolla as a loan car. It made me consider if maybe I would be better off in something lighter and more economical than the Audi and I was curious what a Prius would be like.

In March I went to California on a business trip. A friend there whose wife drives a Prius let me do a short test drive. Pulling away from a traffic light, where the engine had been automatically stopped, felt very unusual: The car starts up running only on its electric motors, without the noise of the engine, which comes alive only as you already start rolling.

Finally in late June my wife and I started shopping around for a buyer for the Audi and for a good deal on a Prius. The waiting list from custom order to delivery turned out to be about 5 weeks, far less than I had seen quoted by US-based posters on websites. I went for the “S Touring” model with a navigation system as an option, which my wife had been requesting for years. The touring comes with HID headlamps (I had never been happy with the conventional halogen lights on the A4) and a firmer suspension than the base model.

We also added a gadget called “etc” (electronic toll collection), which handles toll road charges for motorways here in Japan (most motorways here charge for usage). There are special lanes for etc-equipped cars at toll gates, which make it quicker to get through, as you just have to slow down to 20 km/h to pass through while your car contacts the wireless booth equipment. Before we always had to queue in a line to hand a prepaid card, cash or a credit card to a guy in a toll booth. There are discounts for paying by etc, I guess because the operating company can cut back on staff.

We returned the Audi on the day its bi-annual vehicle inspection became due. We then relied on bicycles and public transport for four days, until the Prius arrived on the last day of July.

Only after I placed the order did I google for crash test results, but the outcome was very comforting: Though the Prius was some 200 kg lighter than my 1999 model Audi, it did as well as the latest A4 model (2008) on crash test results. In fact it had the highest rating of any car tested for kids in child seats in the EuroNCAP tests. As far as interior space is concerned, I didn’t have to give up anything. If anything it’s more spacious than the Audi and it offers the practicality of a hatchback.

Last weekend we drove down to the coastal town of Enoshima on the Pacific, about 35 km from here, which on a Sunday takes 1 1/2 hours because of traffic jams. The Prius will simply shut down its engine whenever stopped, whether at a red light or in slow traffic. Even then the air conditioner (essential at 30+ centigrade in hot and humid Japanese summers) will keep you comfortable, as it’s electrical and draws current from the car’s powerful traction battery that also drives that car’s electric motors.

The NiMH battery will get recharged when the engine is running again or whenever you push the brake pedal to slow down the car, which switches one of the motors to work as a generator. This “regenerative braking” extends the life of the brake pads too.

Other auxiliary systems that on conventional cars are driven directly by the engine via a belt are electric on the Prius, such as the power steering and the brake servo. These always suck some power on conventional cars, whereas on a hybrid they only draw power when needed, making it more efficient.

On the way back we also drove at 80-90 km/h on multi lane highways, with the multi function display (MFD) showing better than 20 km per litre (better than 5 l per 100 km). We never had any trouble keeping up with traffic.

UPDATE (2008-08-10):
With about 250 km on the odometer, the displayed fuel consumption average is now around 16 km per litre (6.25 km per 100 km or 38 mpg US). Other than the weekend trip, it was mostly short trips to a shop or to drop off or pickup a family member at one of the train stations, which are about 3 km away. At our average of about 900 km per month this means the Prius is burning some 90 to 100 litres of fuel less per month than the Audi A4 it replaced, as well as running on a cheaper grade of fuel (regular instead of premium unleaded).

According to the website of the UK Department for Transport the Prius is not the car with the lowest CO2 output per km in Europe: It is undercut by two other cars. The Polo 1.4 TDI Bluemotion and the SEAT Ibiza 1.4 TDI Economotion both use the same 80 PS VW/Audi turbodiesel engine. At 99 g/km they output about 5g less CO2 than the Prius. However, these cars are classed as “superminis”, which offer considerably less space to passengers. Most people fail to realize how spacious the Prius really is compared to its competitors. Based on interior space the EPA in the US actually puts it into the “mid-size” category, along with the BMW 5-series and the Audi A6. Below the 5-series and A6 in size are the 3-series and A4 (rated as “compact” cars by the EPA). Below that is the A3 / Golf / New Beetle (“minicompact”). And one more size below that are the Polo and Ibiza.

UPDATE 2 (2008-10-16):

In two and a half months of ownership, our Prius has clocked up over 2500 km (1530 miles). My daughter accidentally reset the average fuel consumption display after 100 km, but in the 2400 km since then the car has averaged 18.9 km/l or 5.3 litres per 100 km or 44 miles per US gallon.

Keep in mind that most of our trips are to pick up or drop off a a family member at a station 3 km away, so most of our trips are no more than 6-7 km on a cold engine. Also, almost all our driving is urban, with plenty of traffic lights / stop and go traffic. If your average trip is longer or you drive more across country or if you live in an area that’s flatter than hilly Yokohama then you’d probably see even better fuel economy from this car.

Toyota Prius hybrid versus BMW diesel

The Sunday Times did a road test, driving a BMW 520d SE and a Toyota Prius from London to Geneva. The BMW used 49.3 litres of diesel, versus 51.6 litres of petrol (gasoline) used by the Prius.

While the BMW’s results are clearly respectable, the figures quoted in the Sunday Times article do not tell the whole story.

For a start, about 40% of the trip were on motorways, another 40% on B-roads and the rest in urban areas. A driving mix that includes only a token 20% of urban driving is hardly typical for usage patterns of most motorists in our largely urban / suburban societies (for example, 79% of the US population lives in urban areas, with most European countries having similar rates). This unusual mix seems almost purposely designed to ensure that the advantage of the hybrid drive train of the Prius would lie mostly idle: Driving at constant speed on a flat road, you are not going to see any real benefits from a hybrid system, which really thrives in stop-and-go rush hour traffic with lots of traffic lights, as most of us experience on the way to work or home.

Secondly, even with these skewed parameters, the BMW lost out on greenhouse gas emissions. It burnt 10.84 Imperial gallons (13 US gallons) of diesel, while the Prius used 11.34 Imperial gallons (13.6 US gallons) of gasoline. Because of diesel fuel’s 15% higher carbon content by volume, the BMW added 131 kg of CO2 to the atmosphere versus 120 kg by the Prius.

Personally, I see no reason why in the long-term efficient diesel engines can not be mated to a hybrid system and have the best of both worlds. Sure, it may not yet be cost-effective at current fuel prices, but things may look very different 10, 20 or 30 years down the road.