Toyota making progress on plug-in car

It's still P&G whether the pulse is fast or slow, even now.
But I believe P&G will be an important technique to get maximum extended range out of the PHEVPrius' plug in capacity.

I was just thinking about that while P&Ging in EV mode moments ago.

 

Coasting will be possible (with regen happening) but who is to say that any new PHEV will allow a "glide" by slightly putting down the accelerator. Gliding might not be available.

 

P&G will always be required to get maximum efficiency as long as the pulsing is done using primarily engine power and the gliding is done coasting.

P&G using solely electric power will never be required to get maximum efficiency and in fact will reduce efficiency. The more current you pump through the electronics, the more energy you lose to heat. So P&G under electric power will result in less range.

So, IMO, in a properly designed PHEV, P&G while in "EV" mode will be less efficient. But once the battery drains down and the car resorts to charge sustaining mode, P&G will be more efficient. If P&G results in higher efficiency while in charge depleting mode, then compromises were made and the engine is running more than it should be.

 

Why not? Glide just means 'no power to the wheels'. You can glide now when in electric mode, either forced with EV switch or when the computers decide to shut down the ICE because it isn't needed for the current load.

 

What would be the point of no EV range?

I expect (hope??) it will have:

An EV/Hybrid switch since only the driver knows if they are going 1 mile up the hill to the store or 10 miles on the Interstate at 55 MPH followed by 10 miles of stop and go at 35 MPH max. I wouldn't want it to use up the battery going 55 MPH when I can currently get close to 60 MPH summer with my 2004 non PHEV Prius then have to use the ICE for the stop and go.

When in Hybrid mode, I expect it to run exactly as it does now, using electric boost as needed. With a much larger battery capacity, it should be able to get better mileage all around.

It should head out in EV mode under all circumstances and STAY there unless the battery SOC gets too low OR the EV/Hybrid switch is set to Hybrid. Once the battery SOC gets low, it should switch to Hybrid mode automatically.

 

Glide is a special case of no power to the wheels AND no regen. You can glide only if you push the gas pedal in a bit - a quirk of the Prius - not necessarily available in other future cars.

 

Has anyone figured out how much charging up the 2010 will affect their electric bill and compared that cost to the cost of their gas bill for the 2008-2009's?

 

The NiMH battery in the RAV4-EV costs more than $40K in 2000. Toyota sold a few of them at $42K in 2002 at a big lost for good public relationship instead of crushing them like GM. The EV1 is the same and has no market for it to be sold at $80K. There is no conspiracy to kill the electric car.

 

The total range of the car, not the EV range. The EV-1 went about 120 miles on a charge. The Volt, if it ever existed, could operate as a gas-powered car, and drive all the way across the country as long as there's a gas station every few hundred miles. This won't be possible for EVs until there is a network of fast-charging stations.

Correct. P&G makes the gasoline engine more efficient. It's irrelevant for an electric motor, which is efficient at a very wide range of RPMs and power output levels.

P&G improves the efficiency of the gas engine, as noted above. It's relevant for the Prius because the Prius gets all its energy from gas. It would be relevant for a PHEV Prius after the grid charge is depleted, but not before. The grid is an inherently much more efficient energy source than any small ICE.

My little Zap Xebra goes three miles per kilowatt-hour. The Prius is heavier and will take more energy to propel, but my Xebra has a cheap and inefficient DC motor. While driving style makes a difference in electric consumption in any EV, just as it does in gas consumption in the Prius or conventional ICE car, I think a reasonable assumption is that with fairly conservative driving, you should get around 2 or 3 miles per kWh.

Electricity prices vary. I pay 6 cents per kWh, so my Xebra costs 2 cents per mile. Probably 2 to 3 cents per mile with a grid-charged Prius in EV mode. (This is why having a long EV range is important: it extends the time you can be consuming much cheaper energy.)

BTW, battery capacity today is very expensive. An automaker building a PHEV or EV today has to consider how much the consumer is willing to pay, and this will determine how much battery capacity they will install, and therefore the range of the car. Rising gas prices are an incentive to buy a bigger battery pack, as this will enable a PHEV to use cheaper grid power for longer, before more expensive gasoline must be consumed.

 

So there is no official statistic for the plug-in that states what the milage per kWh would be, at least not yet?

I hope they intend to figure out that statistic.

 

Not me I just need one with a 250 mile range. I'll be 100 mile round trip from the nearest town. It would be nice to get there, do all my driving and get back without having to worry about running out of juice.

I am with the other guy looking at 2012. My next car will be a plug in or an all electric. Hopefully something like the Think Ox.

 

Sorry

 

Toyota would be foolish beyond belief to eliminate the single biggest operational asset designed into the car. It wasn't a quirk, it was genius.

 

I'll pulse and glide on a PHEV grid charge and go way further than those who don't. Exploiting kinetic energy is way more efficient that any electric motor and the only time regen is efficient is if you have to come to a stop.
Which of course at some point we must. So it's there to capture that energy. Otherwise regen is nothing more than friction slowing your progress.

 

No official statement from Toyota, perhaps, but the information is widely available. There are enough EVs on the road that it would be a simple matter to compile information about miles per kWh and compare. As a first approximation, take my 3 miles per kWh from my Xebra, and ask Darell what he gets with his Rav4EV, and average the two. His car is heavier but probably has a more efficient motor. More in-depth, gather the figures for other EVs.

The reason you are mistaken is that P&G works because the ICE is so inefficient at very low power output. P&G improves on that overall FE. A pure EV or a PHEV operating in EV mode from a grid charge, does not suffer from that problem because the electric motor can operate efficiently at the very low power output needed to just compensate for the vehicles rolling friction.

Here's another way to look at it: To maintain a constant average speed on flat ground you only need to compensate for the rolling friction and the wind resistance of the car. This is a fairly small amount of power. A conventional car accomplishes this by running the ICE at low power, where it is terribly inefficient. The Prius, because it's able to easily start and stop the ICE, allows you to give the car a pulse, operating the ICE in a more efficient (higher power output) range, and then shut it off while the car coasts, gradually losing speed due to friction. You are giving the car a larger impetus than it needs to maintain speed, and then letting friction slow it down, and then repeating. This works because the ICE is so much more efficient at the higher power output! But an electric motor is just as efficient at low output as it is at high output, and furthermore, it is much more efficient than an ICE. Therefore an EV can maintain speed by using the actual amount of power needed. There is no gain in efficiency by giving it a large pulse of power and then coasting. Either way you have to overcome friction and wind resistance to keep moving. With an EV there is no efficiency advantage in breaking down the needed energy into brief pulses.

You are correct about regen. But that has no bearing on the question of P&G.

 

I believe Our defintions of pulse and glide are different. You're talking about the original , unrealistic, often criticized technique, used on flat terrain with the dramatic speed variations that result.. Driving like that may be less efficient with an electric motor.
I'm talking about the everyday application where the pulse can be at any rate, for any duration that would be appropriate for the situation or desire of the driver. The glide is what's most important. I'm talking about exploiting hills, and necessary speed variations, planning, using the kinetic energy of a glide, to move forward and even maintain speed in the process. That energy free form of travel will always exceed the efficientcy of any electric motor.
That's why I'll go further on a grid charge than those who don't exploit a glide. And you gotta pulse in order to glide.
Surely Toyota will be smart not to eliminate that characteristic in the programming of their PHEV.

 

I believe you are right, its a terminology problem. What you are referring to is I believe most commonly called "momentum driving." This is widely practiced in all sorts of vehicles from gasoline to solar to EVs to bicycles. It is also the most efficient way to drive a Prius according to most. P&G and momentum driving are completely different (though not mutually exclusive) practices. P&G deals with maximizing efficiency at steady state cruising, where the vehicle's momentum can't really do anything for you.

Rob