New way to use EV mode to increase MPG?

<div class='quotetop'>QUOTE(Three60guy @ Jul 3 2006, 01:26 PM) [snapback]280552[/snapback]</div>

I have not tried this as it is opposition to how I believe EV mode is best used That said, I DO something similar leaving a parking lot where the chances of the ICE running to warm up while I wait to get on the main road are high.
Generally, I save the EV for flat sections of road where the car would go into EV on its own if I had the opportunity to stop the requisite 6-10 seconds (Stage 3??). The other time I might use it to increase mileage is where I know I will be recharging it because the next section of my trip is downhill or over 42 MPH. Since there is not all that much capacity in the hybrid battery, I figure it best to use gas to get to 30 MPH then electric to maintain the speed. In the summer, the car does this all on its own. In the fall and spring, sometimes I need to force it. In the winter, it can sometime be so cold the car won't allow EV even if I have the climate control turned off.

 

I thought of it also and decided not to do that due to HV battery life. I think HSD design allows it to do that. The fact that Toyota allows up to about 15 mph in normal mode kinda indicate that they want to extend HV battery life to the life of the car. Otherwise, they would've program it.

Hopefully with Li-ion battery, the next generation Prius would go up to 34 mph with pure battery power in "normal" mode.

Dennis

 

I've been doing pretty much the same thing as bruceha_2000. I cant tell either way if it improves or decreases MPG but all I know is my MPG keeps going up.

 

yay- so you did the mod!

i kinda do the opposite in terms of gas engine vs electric motor usage. i try to accelerate with gas and get it up to speed asap (well, within reason) and then coast on electric.

i kick over to EV when i'm coasting to a stop sign or during the first section of my regular commute when i reach a stoplight about 60% of the time and don't want the car to be sitting and warming up that whole time.

bottom line is, you gotta do what works for you. this sounds like it works for you since you're seeing increased mpg. and since everyone's philosophies on driving strategies, ev mode, coasting, etc differ somehow, we're going to see the smattering of opinions that we're seeing here.

so, more power to ya! and let us know how it works long term.

 

<div class='quotetop'>QUOTE(Three60guy @ Jul 3 2006, 01:48 PM) [snapback]280562[/snapback]</div>

From Panasonic EV site, they gave example of life cycle for battery cell used in Prius. They referred to as "Pulse Cycle" and we never really figured out what a Pulse Cycle actually mean. Is it dischage/charge cycle between 40% and 80% SOC? We don't know but after 9,000 Pulse Cycles, internal resistence raised to the level similar (judging by slope of the graph) to 150k miles or life time of the car. The more you use EV mode, the faster you are going to use the Pulse Cycles for sure. Also note that after 150k miles, the HV battery pack is still in a great shape so there are plenty of life left to spare. I guess it will be up to each individual on how they use their HV battery pack. See graphs below:





Dennis

 

<div class='quotetop'>QUOTE(Three60guy @ Jul 3 2006, 10:48 AM) [snapback]280562[/snapback]</div>

Oh yeah! I remember your snotty anti-EV mode comments now! Great to see that you've been assimilated! I do what Galaxee does... I use relatively agressive ICE firing to accelerate (according to the pulse-and-glide camp, this is the best use of the ICE - NOT cruising at low power levels). I mostly only use EV mode for low speed vehicle shuffling in my garage and driveway when I'd otherwise have to suffer through a cold start each time.

 

<div class='quotetop'>QUOTE(Three60guy @ Jul 3 2006, 10:48 AM) [snapback]280562[/snapback]</div>

Same here. What turned me around was reading that the EV software would prevent the Prius from going into EV mode (and drop you out) if the conditions weren't right.

Keep an eye on your mpg, if you abuse the EV mode it'll decrease as the ICE needs to run to recharge the batteries.

 

<div class='quotetop'>QUOTE(Three60guy @ Jul 3 2006, 03:26 PM) [snapback]280602[/snapback]</div>

Brownnoser

 

It is my considered opinion that the method in the OP is the best possible way to decrease your mileage. That is, to burn more gas. The reason for this is that the gas engine is most efficient when it is delivering a relatively larger amount of power, and the electric system is least efficient when called on to deliver a lot of power. The reason for the latter is the conversion inefficiency.

My system, like galaxee's, is to use EV for slow-speed steady-speed driving on a level or downhill road. As I pull up to a stop sign I disengage the EV so as to use the gas engine to accelerate to speed, and then engage EV again. This eliminates the inefficient use of the gas engine at slow, steady speed, substituting the efficient use of the electric system for low-power-demand situations.

Notice that my system is much like what the car does itself if it is properly warmed up: It uses the gas engine to accelerate, and then goes into electric mode for the steady-state driving. This is the most efficient use of the electrical capabilities of the car.

The suggestion in the OP is exactly the opposite of what the car does if left to its own devices. Do you really think that Toyota got it backwards?

Improper use of EV will not harm the car, because the car protects itself and will disallow EV mode if conditions are outside its parameters. But you will burn more gas. Probably not a lot more. But more.

Another good use of EV is when you know you are coming to a big downhill. Use up the charge that will be recovered on the downhill, so as to create more space for that recharging.

 

I use the EV when coming home at the end of the day to run the battery down. Then when I start next day the ICE can charge the battery as it warms up.
I do not know if this affects fuel consumption but in theory it should increase milage because the ICE has to run anyway to warm up.
Any comments on the technique?

 

360, I expect that if you keep doing this long-term, your perceived
increase will start dropping off and possibly even go the other way.
You've got a system that's very good at coupling 72% of the engine
torque straight out to the wheels, allowing you to NOT have to
convert into and back out of electric power, but you've heard all
that before. Yes, please do keep us posted, especially if you get
time to do consistent/controlled comparison testing...
.
_H*

 

<div class='quotetop'>QUOTE(Orf @ Jul 3 2006, 05:44 PM) [snapback]280711[/snapback]</div>

I was recommending this technique in the fall of 2004.

But it mainly applies in cold weather. In warm weather the engine warms up so quickly that it seems unnecessary.

 

You're still relying on a perceived short-term gain. Most people
manage traffic that way, too, racing up to close a gap, and look
where that gets them -- massive traffic jams, and *later* arrival
at a destination.
.
Drive some loop one way, and then drive it again the other way, and
compare. Make sure the loop is long enough to cancel any effect
that state of charge could have on it.
.
_H*