If the electric motor were a bit more powerful

The Prius's electric motor has had a boost in power since the original Prius... it's gone from 44 hp to 67 hp right now...

So I think Toyota is doing the best they can...

 

<_< The Prius engineering is remarkable. The balance between the ICE and electric motors, combined through the CVT is silky smooth. Changing one element would require another analysis of the entire system. Other "so-called" Hybrids are utilizing the electric motor to boost accelleration and achieve only a very marginal increase in fuel economy and pollution. One could also speculate that re-programming the ECM's to change the operating characteristics of the Prius could force the electric motors to operate to a higher MPH - but then we'd lose efficiency in replacing the stored energy in the main traction battery. It's a well-balanced system.

If a buyer prefers a "muscle" car, Prius is not the one to buy.

Just my 2¢ worth, not intended as criticism.

 

It's my opinion the trouble is the batteries. Right now, battery technology is not up to it. A more powerful electric motor is no problem. The problem is the capacity of the batteries.

I wish the computer would let me push the electric harder before kicking in the ICE. It is tough when the car thinks it's smarter than the driver. Maybe someday they will do what WE want.

Much better batteries are just around the bend. Start saving for an '08.

jrohland

 

Believe it or not, it really is the electric motor that doing most of your acceleration from a stop. The Prius has a planetary gearing system and the engine (ICE) is always directly mechanically connected to the wheels. It is effectively like being in high gear at all times. (And by the way, there is no "Reverse" gear)

When you are accelerating, most of the power from the ICE is applied to the MG1 (motor/generator) in the center of the planetary gears, which provides electricity for MG2, which is the electric motor/generator that is used to actually move the car. As the car's speed increases, more power from the ICE is sent directly to the wheels rather than MG1.

So, the electric motor (MG2) is actually what is providing you the initial acceleration. It's just that most of the electricity for it is coming from MG1 which is being spun by the ICE, rather than from the battery.

I didn't do the description justice, but here are a couple of links that do.

This one is a bit on the technical side (but not too much) and might be a liitle hard to follow.

http://home.earthlink.net/~graham1/MyToyot...ransmission.htm

This one is a little more straight forward and explains what happens during engine start, acceleration, coasting, and braking.

http://home.earthlink.net/~graham1/MyToyot...gOnAsIDrive.htm

 

i prefer to accelerate fast and reach coasting speed early to gain that mpg back. of course, that also depends on traffic around you.

we all have our driving preferences- until they come out with something better, try to work with the disadvantages.

we're all guinea pigs, you know

 

Perhaps you should get an EV switch, although I don't know how that works with that acceleration. As for me I just move off as smoothly as I can, and if I need to "punch it" she's very quick off the line (at least until 34mph).

 

i didn't think you were complaining... typically i complain more about the traffic around me than the car itself :lol:

it does take a while to gauge how far down you can press the pedal and still be in electric mode. i am still amazed sometimes how far i can drop that pedal and not hear the ice kick in...

but yes, it would be nice to accelerate at the rate of traffic in electric, i hear ya.

 

Try leaving more room in front of you. I tend to glide until traffic ahead slows down. Then I let off the accelerator and let the regen braking slow me down until I can pulse up and glide again. It beats coming to a near-stop because of following traffic closer.

Of course, this works best when there's only one lane. More than one lane and you risk getting cut off by aggressive drivers!

 

galaxee
I have been away for awhile. No recent trips to Haw River, NC.
There are a lot of good driving tips here. The thing that fascinates me most is that once I returned from driving the 2005 Prius (family was in Africa for one month during the summer and I had the "new car"), I now drive my 1984 Toyota Corolla much differently as well. I discovered that a lot of driving (not on the big road) works just fine on idle and I do even less acceleration and braking. The reason those huge SUV and other vehicle drivers accelerate so heavily is they are in a hurry to reach the next gasoline station. Not having to stop to refuel, we will just sail (I call it "floating") right on by them, happily!

 

Is the valve overlap electronically controlled, or is it a mechanical function? The way to more low end power may be to "de-Atkinson-ize" the ICE, rather than boosting the electric motor. Maybe this is software controlled?

 

HAHA! Someone else gets it! I've only had one person comment on my car's name and I think it was a chemist. You just made my day :lol:

There are plenty of geeky science things out there to name your car after- bet you can even top me if you think about it...

You're in biochem, right? So many possibilities there!

Glad yo hear you're doing well, BoBraxton. I think mileage tips also apply to non-hybrids, hope you're getting some good mileage.
Great philosophy on why other vehicles start up so fast! :lol:

 

dupe post

 

If for fun you just want it to jump:
A. floor it: you'll hear the electrics kick in and get you moving before the gas comes in)
B. get grippier tires: traction control on the Prius could prevent you from getting that "jump" from 0 because it's trying not to spin the tires, although I think the stock tires don't really loose traction from a straight drag-start on normal asphalt

I usually do a "drag-start" from the metered freeway entrance.

 

The Prius is better than you think at being fuel efficient. Sure, accelerating with the motor only seems more efficient, but you have to recharge the battery later, which involves energy losses.(all of your energy ultimately comes from from the ICE, so you have to run it at some point). The gas engine (ICE) is most efficient at higher RPMs, so it's better to run it while accelerating than run it later when you're just cruising along.
So basically, the electric motor has enough power to do moderate acceleration, but the computers choose to use the ICE (plus motor) when accelerating because overalll it's more efficient.
On a related note, people on this board have noted that the EV button may not get you much in MPG unless you really know when to use it.

 

I think the limiting factor in doing what you is the total battery capacity. Also remember in the final analysis all the power you use comes from gasoline, and as others have pointed out there will be losses in the conversion process.

 

I think part of your problem comes from the fact that the instantaneous mpg readout is very misleading: it does not take into account the electricity being used or generated. Acceleration on electric-only is NOT efficient, as it must be replaced later. Patient folks have determined that the most efficient way to accelerate is to drive it like a normal car! Not overly slow, and not overly fast. No matter what you do, acceleration is the most energy-consuming thing you can do. And if you hide the numbers by doing it in EV mode, you'll pay for it later.

Extremely adventurous folks have added battery capacity. (Don't try it yourself. It is a job for an advanced electrical engineer willing to riks damage to his/her car and self!) They have determined that with more battery capacity the car gets better mileage, because the purpose of the battery is to buffer or balance the load. However, the expense is high, and for Toyota is was a compromise among weight, cost, and capacity. (They'd lose market share if they put another $2K worth of batteries in it.)

Another place for improvement is the limit on how fast you can draw down or recharge the batteries. Expect advances in future models. The ability to recharge the electrical system faster will allow more energy to be recaptured via braking, and the ability to draw down faster will allow the motors to get more energy when conditions warrant. It's been said that super capacitors may be in the future of hybrids, to buffer the flow of electricity to and from the batteries, thus mitigating the limits of the speed at which the batteries can be charged and discharged.

As for de-Atkinsonizing the engine, you don't want to do that either. The Atkinson-cycle engine is more efficient than the Otto-cycle engine. It cannot be used in a conventional car because of its low torque. But with the high torque of MG2, the Prius does not need a high-torque engine, and can happily benefit from the increased efficiency of the engine it has.

I honestly believe that the Prius is the most efficient car that can be built with today's technology at an affordable price. 2008 is another matter. As I said above, expect advances. Read Graham's web site (the link is in an earlier post).