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Discussion Starter · #1 ·
I have talked about some of the big improvements I would like to see in the Prius, but there are some smaller improvements I would like to see that would be relatively simple to incorporate by Toyota based on a number of test drives:

1. Incorporate a brake switch. Currently, as I understand it, the B setting on the gear lever only works below 20 MPH. Letting off the accelerator produces mild regenerative braking, which has to be negated for pulse-and-glide. stepping on the brake produces more regenerative braking. I wouod like to see a brake switch incorporated, with at least 4 settings:
a. Automatic: Works same as current setup
b. No braking: For pulse-and-glide
c. Mild braking
d. Heavy braking
The braking could also be three-stage.
A brake switch is common on heavy trucks, and motorhomes, and has several options for the amoount on engine braking desired.

2. Delay ICE kicking in from a stop. After driving several Priuses, I realized, it takes a very small amount of pedal travel before the ICE kicks in. With 295 Lb-ft of torque, the electric motor should be able to easily take the car away from a stop.

3. Get the instrument panel down in front of the driver, instead of being a hood ornament!
 

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Being the owner of a motorhome, I can say that the brake switch is extremely useful, but completely inappropriate for the Prius. In the RV, it really keeps the vehicle from picking up speed while going down hill. Due to it's weight, that provides a significant and necessary safety mechanism as well as saving the brakes.

In the Prius, it appears that the brakes can easily last over 100,000 miles so there is no need to "save" them. Also, it is very easy to control the Prius' speed with the current mechanisms so you won't get any benefit there. Overall it would be a complication that many are unfamiliar with and would provide no benefit.
 

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Discussion Starter · #5 ·
Redwine,

The suggestion has nothing to do with saving the brakes, but rather having control over the amount of regenerative braking. Instead of modulating the accelerator to have the car coast with no regenerative braking, wouldn't it make a lot of sense to have positive control over that function?
 

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Again, it is a needless complication that most people wouldn't want to deal with. I would guess that most people just want to approximate normal driving and would just let the car do what it is programmed to do. It is only the mpg junkies that get so obsessed with this stuff. That hardly seems like reason enough to add some foreign control function to a car that they tried to make as normal as possible.
 

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Discussion Starter · #7 ·
But if they included an auto setting, you would not have to deal with it. At the same time, those who wanted to, could stretch the car even further. The Prius is probably viewed as a "geek" car anyway, why not go one step further?
I find it interesting, though, that after spending some time on this forum, I get the impression most Prius owners have the attitude that the Prius is as good as it's going to get--and I'm not willing to buy that.
 

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They went to great lengths to make the car as "normal" as possible. What you are suggesting is simply in conflict with that design goal. Nothing more, nothing less. Adding a feature that most people will ignore raises the cost for everyone with no benefit. If I was making cars, I wouldn't make such a tradeoff.

I don't know where the part about concluding that everyone thinks the car is as good as it can possibly be comes from, based on this line of discussion. We were talking about a single feature that doesn't exist in any car and whether it would make sense in here. If they improve technology in a way that increases MPG, I would be very happy and jump on the chance to buy one. There are a few features I would like to see in the car too, such as more adjustable seats but I don't think that most people would equate the extra proposed complication as an improvement.
 

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Discussion Starter · #9 ·
If they wanted to make the car normal, they would not have put the "dash" way up front!
It seems to me they designed the car for minimum driver involvement. It's the "hybrid-for-dummies" approach I'm not too keen on!
 

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I love having the instrument panel where it is. I find it much easier to see peripherally than having to take my eyes off the road to focus behind the steering wheel. And when I'm focused on the speedo, I can still see the road well peripherally.

Susan
 

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I go with redwein on this one. Toyota was endeavoring to prove hybrid is a viable method to go.
You won't find 300,000 purchasers buying "geek" cars. I do believe the dash lack of instruments (coolant temp, and oil pressure) was a mistake and an "ICE" on light would be great. However except for the gear selector they have done a creditable job and have created a small market. Not enough to scare the rest of the automotive world into seriously thinking hybrid but there is a small ***** in the market now that there wasn't until 04.
I think we all can agree that the price of gas will not change the market as the scarcity of it would, and it's probably one place where regulation would be good and required to get the pressure of mid-east oil off our backs.
For what it is the Prius is the best of the few animals out there.
Is it a viable replacement for the American owner? Personally I think not.
I'm going back to one of the smaller SUV's for safety, handling, visability, and comfort. Because of the hybrid and escalating cost of gas my choices for 07's has been enlarged greatly with 5 and 6 speed transmissions, 30 mpg is now getting to be the norm and if you will google Honda CRV and take a look at the interior you will see what I am talking about concerning comfort. For this, I am willing to sacrifice 14 MPG.
If you want to go the distance with this Per, the kits are out there for a paultry $10,000. I'm just glad Toyota did not go this way or "hybrid" would have to be a word you would have to look up in the dictionary.
 

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The display is up near the dashboard in a "heads-up" fashion. It is partly for driver safety - the driver doesn't have to refocus as much from the road to the dash and back as opposed to the under the steering wheel location. This smaller refocusing helps to minimize night blindness as well.

Besides, it is much easier to see it up on the dash, than having to duck around the steering wheel (which usually hides all the important information for us shorter drivers) to see it.

For the Classic Prius, where the display was in the middle of the windshield, it also meant less retooling for RHD and LHD markets, but that changed on the current NHW20...

Last I checked, the Saturn Ion also has a non-traditional display, as does some Cadillacs, for similar reasons.
 

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Per said:
2. Delay ICE kicking in from a stop. After driving several Priuses, I realized, it takes a very small amount of pedal travel before the ICE kicks in. With 295 Lb-ft of torque, the electric motor should be able to easily take the car away from a stop.
I believe the car already works this way. On your next drive, see if you notice that the ICE doesn't kick in until you are going about 7 MPH. The electric motor's high torque does the hard work of accelerating the car from a standstill.
 

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1)As stated, while a braking switch would be a cool toy for some of us, the added complexity and general confusion it would create just doesn't make it practical....Just look how much confusion and misinformation there is about B-mode. In fact, in your post you say you believe it only works under 20mph...that's wrong. It works at all speeds. The 20mph figure is only significant in that if you're in "stealth" at under 20mph and use B-mode it won't force the ICE to spin. If above 20 or if the ICE is already spinning it will continue to spin when you put it in B-mode until you take it out of B-mode again.

2)Intentionally delaying ICE start up from a stop would cause lower FE. It is more fuel efficient to accelerate from a stop (in the majority of situations) with the ICE + electric...that's why that happens.

3)The instrument panel issue's also been covered. It makes sense where it is, much less refocusing is required to glance at it. Certainly your personal preferences may vary, but your opinion on this issue is far from universal. I think every car should have a forward set HUD like the Prius both for convenience and safety.
 

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Discussion Starter · #15 ·
efusco,

I don't see how delaying ICE start would lower fuel efficiency.When the ICE is running, it used gas, when it does not run--no gas? Seems to me the key to better mileage on the Prius would be minimizing running the ICE.

So far, all I have seen is reasons why something would not work. Now Redwein, do you see why I say the folks on here thinks the Prius is as good as it gets? I have not seen a single significant suggestion for improvement so far.
As far as spending $10k for a modification, I have no intention of buying a $30k vehicle to have a back-yard mechanic screw it up! Any modification would have to be done by Toyota before I bought it under full warranty!
 

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As far as not running the ICE so soon for better fuel efficiency when starting off from a stop, there is a significant loss generating electrical power from the ICE and a further significant loss recharging the battery. I've heard 50% loss frequently in the charging plus perhaps 20% loss in generation. My experience with these types of batteries leaves me no reason to doubt these numbers. So the more power you draw from the battery the more power you waste. The hybrid system (battery/generator) is there to enhance the performance of the ICE in the Prius, and of course to recover "wasted energy". There is a balance to attain here, performance gain vs loss in conversion of energy. I'm not addressing the efficiency of the ICE in converting chemical fuel energy to power at the crankshaft as that loss occurs whether you use ICE power directly or for generating electricity.

As far as improvements, personally I think the following might be appropriate:
1. More aluminum in the body to reduce weight - perhaps a full aluminum body.
2. More use of LEDs and other energy efficient parts to enhance the overall efficiency of the car. Cost benefit here wouldn't be good though.
3. Some engineering would have to be done here (and probably has been by the Toyota team), but a larger battery might allow the system to operate more efficiently. The current choices Toyota engineers made might be best or they might be due to availability of battery components.

A "better Prius" may not even resemble what we have now. It may become an EV with a small ICE for "performance enhancement" - basically the opposite of what we have now. Of course, then you could say it's not a Prius, but something else. ;)
 

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I see two other reasons for having NULL drag effect: safety. Most people drive automatics, and since this car is sold specifically as an automatic, people would expect the car to slow down by a specific rate when they let go of the gas. If it did not do that as expected, one could hit objects (such as cars) in front of them.

As for 'delayed ICE start', the main reason is the very thing you stated. All energy that this car uses ultimately comes from gas, either immediately, or deferred later. Even regen braking gets its energy from gasoline stored up as kinetic or potential energy.
Yes, the motor does have great torque and power, but the battery does not. The rest of the power MG2 needs that the battery cannot provide comes from ICE via MG1, if not through direct mechanical couple.
Remember, the PSD allows the hybrid to operate in parallel AND series, more often a combination of the two, depending on what's most efficient.
 

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Per said:
Redwein, do you see why I say the folks on here thinks the Prius is as good as it gets? I have not seen a single significant suggestion for improvement so far.
I really don't see it. I think you are mistaking people not thinking your particular suggestions are improvements for there being a widespread belief that improvements are not possible. I agree that it does seem that many people are very happy with their Prius as it currently is and it only stands to reason that the more happy you are with something, the shorter your list of desired improvements would be. That's just common sense.
 

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Discussion Starter · #19 ·
Dan,

You definitely provide the best input I have seen on this forum, and it dawned on me that you are absolutely correct, that all the electrical energy in the Prius comes from the ICE. Even a bigger battery would not help much! So it boils down to the efficiency of the ICE and the system, if you disregard the potential for plug-in.
Seems we get kind of stuck on the efficiency aspect, although one way to improve would be with a diesel engine.
Interesting side note on diesels: Norway, which just elected a red-green government, gave tax credits to diesels, making a diesel version of the same car much cheaper (cheap car is a relative term in Norway!) than it's gas sibling. They are more concerned about CO2 emissions, than other emissions.
 

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Per said:
efusco,

I don't see how delaying ICE start would lower fuel efficiency.When the ICE is running, it used gas, when it does not run--no gas? Seems to me the key to better mileage on the Prius would be minimizing running the ICE.
This is an illusion. Where does the power for the battery come from? Gas. Power directly from the ICE to the wheels is more efficient than power from the ICE, through the inverter, to the battery, stored in battery, back through the inverter, to MG2 and then the wheels. There are heat and other losses when the energy flows in that fashion. Further, heating of the Inverter due to heavy use of electricity causes it to be even less efficient. This is a complex process, but let me assure you that driving predominantly in electric mode is rarely if ever better or more efficient than letting the hybrid system work it's magic.

So far, all I have seen is reasons why something would not work. Now Redwein, do you see why I say the folks on here thinks the Prius is as good as it gets? I have not seen a single significant suggestion for improvement so far.
As far as spending $10k for a modification, I have no intention of buying a $30k vehicle to have a back-yard mechanic screw it up! Any modification would have to be done by Toyota before I bought it under full warranty!
Let me add a thought that some of us have pondered/hoped for before. Just as Toyota currently offers the standard package and 'touring' package, many of us uber-geeks would like to see some sort of "Tech" package. Something offering more guages, a CAN-View, EV button, maybe additional battery capacity and/or plug-in capacity, etc. Your brake switch would seem a good candidate for something like that. The people that bought the tech package, presumably, would be willing and eager to learn to take advantage of those kinds of things in pursuit of their uber-mileage and such.
 
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