Why we purchased a Toyota Prius

We purchased a Toyota Prius on May 18th when my wife’s work car came off its lease. This is a long post but I hope it serves as a primer to those interested in how a Prius works and what lead to our decision to buy this car.

The first thing to know is that the days of paying sticker or above for a Prius are over. That may change in a few years when the third generation of the Prius appears as a 2009 model, but Toyota started making the Prius on a standard production line in Japan (the only place they are currently made) allowing them to get more cars on the market. A savvy shopper should be able to knock about $1,200 to $1,300 off the sticker price.

Initially we thought that renting for her was the way to go since she is in a profession where she needs a nicer car. I wanted to test drive a Prius out of curiosity. We were surprised off the bat at how much room there is in the car. The 2nd generation of the Prius is actually a mid-sized car and not that much smaller than a Camry.

The second thing that surprised us is the amount of pickup the car has. It’s more than adequate for any kind of driving you will do. The electric engine produces 295 pounds of torque. Here’s a nice primer on the Toyota Prius Electric Motors/Generators.

Because of the electric motor and the CVT transmission you don’t have actual shifting, it’s just linear power all the way. It’s strange at first because you keep expecting that little jerk when a traditional cars shifts into the next gear as you get up to speed.

After the test drive I started to do some serious research on the Prius. My wife discovered that I am a maximizer. So if you followed that link and know what that means. Fortunately, Ann is a satisficer or we’d be in trouble…

Now the first logical thought I had was that a Prius had to be really complicated car, with many more things to break down or go wrong. My research showed the opposite. The first item that piqued my interest was the Consumer Reports car reviews which had the Prius scoring high on all fronts for reliability.

Then I came across some good information on “Bob is the Oil Guy” web site. As funny as that site sounds it’s THE place for some serious gear heads. The following excerpt is from a user known as “Ekpolk,” who is a forum admin on the site. He is a Prius owner and lists his occupation as “Colonel, USMC /Attorney” who is now retired.

tripleM makes a good point…Despite Toyota’s reputation for durability, there seems to be so many more components on a Prius that, when the car is kept for a long time, I’d think could really hit the wallet hard when its time for routine maintenance. At some point, the customer becomes responsible for repairing and maintaining the battery packs and all the hardware that goes with them. If you’re planning to keep the car for a long time, you might consider long-term maintenance costs and figure them against the slightly lower MPGs you get with a simpler non-hybrid that doesn’t have regenerative braking, on-board generators and all the computers required to manage the systems.

I’m not as convinced. With the HSD design, you get certain components that are actually much simpler than they are in a conventional car. The transmission is a biggie. The planetary CVT is amazingly simple compared to a modern, multi-speed auto.

As for all the on-off cycling, at least in the Prius, it’s designed to pre-oil itself. MG1, the smaller of the two motor-generators actually spins the gas engine up to just under 1k rpm before the ECU adds spark and fuel. Wear? Check out our typical Toyota UOAs. Also, consider that a Prius can never wear out a starter motor — it doesn’t have one, MG1 performs that function. Alternator? Doesn’t need one of those, and doesn’t have one. So again, while you get some complexity, you get a lot of simplicity.

Read the above discussion.

Then I ran across a guy named Lonnie on the site and he has some interesting posts on the Prius:

I know I mentioned it before but I’ll repeat it here. We manage some vehicle maintenance programs that cover about 8.6k vehicles of all sizes, most in North America from Mexico to Canada and from cars to class 8 trucks, off-road equipment and service boats. This is not science because we can not publish our data but the most reliable single vehicle with 5 years of data, has been the Toyota Prius. The total database covers about 200 Prius’s (certainly not enough top prove anything) over this period. They were usually driven by one or two drivers each and all run past 100k miles, about half past 150k and a 23 past 200k miles. Drivers just would not give them up on schedule. Also, percentage wise more of these vehicles were purchased by the operator at the end of the lease, over 80%. Second place is purchase is about 20%. Some drivers had these vehicles put on them, but very quickly became very pleased with their rides. Not one driver turn back a Prius. Battery failures have been zero and electronic problems have been so few that the last one, on any vehicle was over a year ago. A lot of what people think they know about these funny looking vehicles might be wrong. At one location we even have a pool for best mileage with digital pic’s of the display required to compete. Three maintenance managers have purchased a Prius for their personal vehicles. One has two (does that sound right?). This is not a valid test, just an indication that the Prius might be a reliable car. In the years to come more of these hybrids will be showing up in your town, too.

The Prius has a planetary transmission with no friction parts and no belts and about a dozen major moving parts that never slip, engage or disengage, that is a sun gear, a ring gear, a planet cage and four planet gears, that’s it. We have just over 200 in fleet service and after four years or so they are the most reliable vehicles in a fleet of thousands of vehicles, have the fewest non-scheduled shop visits and are the cheapest to keep on the road, year after year. The only people that don’t believe this are those that have never even driven or ridden in one.

Read the above discussions here and here

Below is another Lonnie post that is very interesting:

We just tore apart a Prius transmission with almost 200k miles on it from one of our cars, wrecked. It as no torque converter, no clutches, just a few gears. It looked like new inside. It has a sun gear, a ring gear, and a few planet gears and that’s it. There has been a lot of talk about the Prius and we all wondered how reliable it would be. We pulled the pan off the engine and look at the bearings and they are like new. We looked inside the cylinders and everything there looks like new too. The batteries are also as good as new. We did that load test on them and it’s impressive how much power there is, there. But back to the transmission. I can’t imagine how you could wear this thing out. It’s made like a swiss watch and the gear wear patterns are almost not there. It also looks like this thinner WS transmission fluid is doing its job, too. With only one forward gear and no reverse this transmission is the ticket to a along life.

The Power Split Device

Read more about the Prius’ PSD ECVT.

While we are on the subject of reliability, now is a good time to mention regenerative breaking, which recovers energy and stores it in the battery, unlike the traditional car in which breaking dissipates the energy as heat. Because your brake pads are only used for emergency stopping and below 7 mph it’s very likely the break pads will last the life of the car.

When you want to slow the car more rapidly than rolling resistance, aerodynamic drag and engine braking, you press on the brake pedal. In a conventional car, this pressure is transmitted by a hydraulic circuit to friction brakes at the wheels. Brake pads rub against metal disks or drums and the energy of motion of the car is converted to heat as the car slows down. The Prius has this exact same braking mechanism, but it has something else as well – regenerative braking. Whereas during coasting MG2 produces some generator drag to simulate engine braking, when the brake pedal is pressed, the electrical power generation of MG2 is stepped up and a much greater generator drag contributes to slowing the car. Unlike friction brakes, which waste the car’s kinetic energy as heat, the electrical power produced by regenerative braking is stored in the battery and will be re-used later. The computer calculates how much deceleration will be produced by regenerative braking and reduces the hydraulic force transmitted to the friction brakes by an appropriate amount.

“What’s this MG1 and MG2 you mention above,” you may be asking? This is one of the electric motors in the Prius. Here’s a very good site that describes and shows the Toyota Prius’ Power Split Device. This is the heart of the Hybrid Synergy Drive (HSD).

After all this research we came to the conclusion that buying might be better for us. After three or four years I can start driving the car and sell off my 98 Camry for whatever it’s worth and use that to fund the next car. By then Toyota will be using lithium ion batteries and plugin technology that will be getting 100 mpg!

There is a lot of technology for a car in its price range:

  • The Multi Function Display (MFD) shows you current power consumption, MPG and controls other car functions like radio, climate control and outside temperature.
  • By-wire technology,
    first made famous as “Fly-by-Wire” technology in fighter planes, automotive “Drive-by-Wire” technology replaces mechanical connections with electrical connections to reduce weight and provide more sophisticated and reliable responsiveness. For example, on Prius, pressing the accelerator simply tells the onboard computer what speed you want to travel, rather than activating a mechanical throttle directly.
  • When the car is put into reverse the MFD (Multi Function Display) shows the view of the camera mounted on the back of the car.
  • Sound and climate controls are on the steering wheel
  • Smart Key System (SKS) keyless entry. With the keyfob on you simply touch the door handle to unlock the car. Push a button on the handle to lock the car. No need to ever get out your keys.
  • AUX in port for the iPod
  • Two power ports
  • Folding rear seats
  • Brake lights use LEDs. That means they should never need changing.
  • Air pressure sensor for tires
  • Heated side mirrors

Safety

Insurance Institute for Highway Safety Crash Test: 2006 Toyota Prius

  • Front Impact – GOOD
  • Side Impact – GOOD
  • Rear Impact – MODERATE

The car also has ABS as standard equipment and front/curtain/side impact airbags

Emissions

The Prius is classified as a SULEV (Super Ultra Low Emissions Vehicle), meaning it is 90% cleaner than conventional gasoline-only automobiles. If you don’t care about more MPG this alone is a major reason why this car is important. With the Prius you seem to have a car that is incredibly reliable, easy on the gas and doesn’t pollute like a traditional vehicle. It’s also fun to drive as you quickly get addicted to the MFD and the feedback it displays.

The maximizer in me is quite happy.

One thought on “Why we purchased a Toyota Prius

  1. Congratulations. We bought a Prius late last year. It is a comfortable, reliable, very economical and clean car, no surprise there. But it is also a fascinating car. The engine, transmission, hybrid system, regenerative brakes, etc are so unlike “conventional” cars, the computer brains are smart and subtle, and the whole car was so carefully thought out by its designers. I find it as interesting and entertaining to drive as my Porsche – a comment that makes some Porsche owners quite upset, but that’s tough.

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