Prius, real science or marketing stragegy?

Heya l,

Tideland makes yet another valid point...

Hybrids have NEVER been the big profit winner for the manufacturer. If they where, they'd have hit big YEARS ago.

Until recently, the general populas (At least American) where interested in gas guzzling SUV's or sports cars.

Frankly, as a marketing strategy, hybrids where a HUGE mistake. That's WHY Toyota didn't build many of them and we all had to get on a waiting list to get one. Manufacturers didn't think the people WANTED hybrid technology.

Just my 2 cents...

Yoda

 

> That's WHY Toyota didn't build many of them

Toyota didn't want to build obscene quantities of hybrids initially. They wanted to do extensive real-world research first, then follow-up with engineering tweaks before reaching the masses... as well as set realistic price expectations (since making a profit later on is very important).

That's why they started with the "full" hybrid type (Prius) in Japan, then released an upgrade in limited quantities to the United States afterward. After that initial success, they released even more of the next upgrade.

At the same time, they were also testing the practical nature of the "assist" hybrid type (Estima) in Japan. That extended research made a lot of sense too, since the original prototype of Prius was never put into production. (It used a Cone & Belt CVT rather than the Planetary type and an Ultra-Capacitor rather than a Battery-Pack.)

At the same time, they were also improving battery technology while also trying to increase supplier contract quantities while also trying to fight a patent-infringement lawsuit.

At the same time, they were also attempting to establish a market for hybrids in a marketplace that simply wasn't interested.

In other words, why rush? There is absolutely no reason to move quickly when you are pursuing such an enormous goal.

Remember, their goal is to change their entire infrastructure to support hybrids in every aspect of their business. That's a risk you should not rush into. It turns out, taking the time to ensure long-term success is really going to pay off. The very first Camry-Hybrid sold will be remarkably well refined, already matching the desires of the masses due to the extensive research done before that. And they'll still be years ahead of the competition.

Patience.

 

The shortest answer to his challenge, which he all but acknowledges, is that the battery is there to capture energy that ordinary cars throw away. Getting even 50% efficiency there IS saving gas. Tapping a bit from the gas engine--at those times when it is operating at high efficiency--pays off when half of that stored energy can be retrieved at times when the gas engine is least efficient.

 

Tadashi-
I've notice that you get some of the best mileage figures around here and it is always good to see it. Keep up the good work.

I rode with my wife today and she drives me crazy. She accelerates up to red lights and generally fails to look ahead and anticipate the conditions ahead. She also accelerates up the hills and drives between 70 and 75 mph. She tailgates to the point that she often has no option but to hit the brakes when something happens up ahead. I relax though when I realize that she is still averaging between 50 and 51 MPG.

 

hahaha sounds exactly like my wife. My knuckles are white and sore by the time I get out of the car.

 

I'm not going to insult your friend. He is probably a very competent science teacher, however he should research the vehicle a little more before commenting further. Depending on what area of science he teaches, the Prius may be a very good lesson to teach for a few days. There is plenty of technical information out there which is correct. I can see the Prius as excellent subject matter for a physics or technology classroom, especially at the high school level.

Anyway the Prius tends to run the engine at optimum RPM levels. I'm going to simplify this as much as possible. This means that at any given time, the optimum RPM level when cruising in a situation requiring ICE power may be above or below what would be required for a conventional vehicle. If the optimum RPM level is above what is actually necessary for a ground speed of say 30mph, the extra RPM coming out of the ICE will be directed toward MG1 and returned to the battery as electrical power. On the other hand, if the vehicle needs some "assist" because of a slight change in the road topography, the vehicle will maintain the same ICE speed, but augment electrically.

In a conventional vehicle, you may run at a lower engine RPM at a 30 mph cruise, however it may not be an optimum RPM for fuel efficiency or emissions. On the other hand, when the road has a slight incline, you will have to add fuel to the engine, thus increasing consumption only for a slight adjustment in road incline. Again, you may not end up at an optimum RPM for efficiency.

The Prius is always working toward the efficiency and emissions goal. Therefore, it is always looking at ground speed and determining the correct combination of ICE and electric power that is most efficient.

 

One misconception most have is that kinetic power from ICE goes straight to the battery, and then from the battery to a motor without any input from ICE. Honestly, when I first got the car, that was my understanding, or close to it.

However, the car can power electrically without using the battery at all, but instead the electric motor can get its power directly from ICE. That is how diesel trains and ships have been doing it for years, as you get much better low end torque and speed control without having to shift gears. The down side of series hybrid like this is that it is slow. Electric motors aren't quite as efficient at higher speeds. But unlike ships and trains, while ICE supplies electric energy to the motor for low end torque, it can also supply direct mechanical power straight to the wheels, as the required torque and speed changes.

Now the science instructor may have a point about IMA to some extent, as there is only one motor/generator, so only the battery is available to accept electrical energy when the motor/generator is a generator, and only the battery is available to supply electric energy when the motor/generator is a motor to assist the engine.
Even then though, there apparently is some savings. The assist is most likely used where not using it would be more inefficient than the inherent electrical losses.

 

Uggh. WHY do so many chicks do this???! I've seen it soooo many times, with another variation that includes a damn cellphone.

I remember a time when I was sitting in the back seat of a car driven by my ex-gf's mom, and looking out the front window, I remember her approaching a real sharp curve and thinking, "Ok, she should be slowing down a bit now....Now.... NOW!" to the point where everyone in the car ultimately ended up yelling at her to slow down as they too realized we were coming into this turn really hot. What made it particularly disturbing, was the way she seemingly had NO CLUE. It was the way her stupid mass of short white hair bobbed around completely oblivious to what was going on, just like one of those stupid bobble thingies people put on their rear decks. :cussing: :cussing: :cussing: :cussing: :cussing:

 

I (for one) would be curious to read about his reactions to the article.

 

EEK! I'm going to get out of the way before you get blasted for that last comment, Squid.

But for the record, I have noticed BOTH sexes who follow the "all gas or all brake" driving philosophy.

 

"A little learning is a dangerous thing." The science teacher's statement shows one of the differences between science and engineering. He's certainly right that battery efficiency is not great, but as others have pointed out it's the reduction in the size of the gas engine, which is allowed by the combination of electric motor and battery, that creates most of the improvement in overall fuel economy.