EV - Is it really helping me?

[bigmahma]

I'm hearing that basically running off the battery is NOT an effective use of the power stored there... as the gas engine has to turn on to charge that battery at a loss of energy.

Can someone please explain to me (so I can be a better MPGer) how this EV button is ment to be used - and how it can help me use less gasoline.

Thank you

BigMahma

[efusco]

There are a few situations that I think it's clearly helpful.
1) Slow moving traffic, particularly waiting your turn to go through a light or stop-sign. IOW, if you're just going to creep forward 50-100 ft when the light turns green but it will turn red again before you get to it I would use EV here. If you hit the accelerator a little to hard the ICE will spin up and run (burn fuel) for a while for no good reason.

2) If you are going less than 35mph as you approach a stop and the ICE is still running. You can force it off as you glide to the stop point where it otherwise would continue to run even as you slow and for a few seconds after you stop.

3)If you're just briefly starting the car to move it around the parking lot or something.

4) It might be a good use if you know you'll have a very long wait until you get on the road. For instance if I'm leaving a local minor league ball game with the crowd and I'll have to be in the parking garage for 15 minutes waiting to get to the road I usually use the EV mode until my turn to pull out onto the main roadway. If I don't the ICE will start, run for a while, shut down...when it gets cold it'll start again and it'll cycle like that even if I'm not going anywhere. That said, I do allow it to start immediately in most parking lots b/c that low speed travel in the first 30 seconds to 1 min. is more fuel efficient than if you were to be in EV until the moment you pull out into normal traffic and immediately have to accelerate up to speed.

And that's pretty much it. Beyond that it's fun but won't do much if anything to help FE and more often than not it'll hurt it.

[bigmahma]

<div class='quotetop'>QUOTE(efusco @ May 7 2007, 09:56 AM) [snapback]436782[/snapback]</div>

There are a few situations that I think it's clearly helpful.
1) Slow moving traffic, particularly waiting your turn to go through a light or stop-sign. IOW, if you're just going to creep forward 50-100 ft when the light turns green but it will turn red again before you get to it I would use EV here. If you hit the accelerator a little to hard the ICE will spin up and run (burn fuel) for a while for no good reason.

2) If you are going less than 35mph as you approach a stop and the ICE is still running. You can force it off as you glide to the stop point where it otherwise would continue to run even as you slow and for a few seconds after you stop.

3)If you're just briefly starting the car to move it around the parking lot or something.

4) It might be a good use if you know you'll have a very long wait until you get on the road. For instance if I'm leaving a local minor league ball game with the crowd and I'll have to be in the parking garage for 15 minutes waiting to get to the road I usually use the EV mode until my turn to pull out onto the main roadway. If I don't the ICE will start, run for a while, shut down...when it gets cold it'll start again and it'll cycle like that even if I'm not going anywhere. That said, I do allow it to start immediately in most parking lots b/c that low speed travel in the first 30 seconds to 1 min. is more fuel efficient than if you were to be in EV until the moment you pull out into normal traffic and immediately have to accelerate up to speed.

And that's pretty much it. Beyond that it's fun but won't do much if anything to help FE and more often than not it'll hurt it.
[/b]

Thanks for your very educated and clear response -


So let me get this right -

If i'm waiting for a light - creeping forward in traffic - lets say - going down the block 2 miles to the grocery store - as long as I don't go above 30 miles an hour - the EV will save me on milage...

Is that right? Or will this cost me energy in the long run when the car tries to recharge that battery.

Thanks

I'd love some more feedback and input on this!

BigMahma

[efusco]

<div class='quotetop'>QUOTE(bigmahma @ May 7 2007, 09:11 AM) [snapback]436795[/snapback]</div>

So let me get this right -

If i'm waiting for a light - creeping forward in traffic - lets say - going down the block 2 miles to the grocery store - as long as I don't go above 30 miles an hour - the EV will save me on milage...

Is that right? Or will this cost me energy in the long run when the car tries to recharge that battery.

[/b]

I'm not 100% sure what you're asking me...but let me explain how I would use EV in this situation.

First of all start the car and let the ICE go through it's normal warm up. This is important both b/c you don't have enough battery to go a whole 2 miles one way and b/c the more warmed up the ICE gets on the outgoing trip the warmer it will be when you start the home bound portion of the trip and THAT'S when you're going to make-up the FE losses you suffered on the out bound portion.

Second, once you've gotten warmed up (probably after a mile to 1.5 miles depending upon speed, traffic ambient temps, etc) you can start thinking about using the EV button....if you're approaching a stop and the car doesn't drop itself into stealth as you drop below 35mph then I'd hit the button. If, at that point, traffic is creaping you could stay in EV. But once traffic gets moving again, even if it's only ~1/2 mile to the grocery store I'd turn off EV and let the ICE run...if it's 1/4 mile or less use your best judgement. If traffic speed is slow, if the battery SOC is at 6 bars or more (over 60% actual SOC) then I'd probably consider EV mode to glide into a parking spot.

Third, the homebound trip could be a little different. Assuming a shortish shopping trip your car may still be near 150 degree ICE temp. I'd definately let it start right away in the parking lot, try to get up to speed on the road and mazimize my Pulse and Glide techique on the way home since the car should be ready for that. Use EV mode as needed under the same conditions in my first post in this thread. Do not use EV just to extend electric only distance though.

[darelldd]

If you use EV mode to drive 2 miles below 30mph... you are wasting gas. EV mode should not be used to travel ANY sort of significant distance if FE is what you are after. If you are just crawling around a parking lot, or around your garage/driveway, it is a great time to use it (as the running ICE cannot be efficient in those situations). If I start cold and know that I'll be sitting still at an intersection after a few hundred feet, I'll use the EV button so I'm not just parked there with the motor running.

Other than these very low-speed, very short distance situations, leave the EV button alone. Using the battery at every chance you get will certainly reduce your FE.

<div class='quotetop'>QUOTE(efusco @ May 7 2007, 07:24 AM) [snapback]436799[/snapback]</div>

First of all start the car and let the ICE go through it's normal warm up. [/b]

I wanted to add here - let it go through the normal warm up WHILE DRIVING. Don't just sit there and let it "warm up."

[efusco]

<div class='quotetop'>QUOTE(darelldd @ May 7 2007, 10:08 AM) [snapback]436834[/snapback]</div>

I wanted to add here - let it go through the normal warm up WHILE DRIVING. Don't just sit there and let it "warm up." [/b]

This is debatable. I chose to let it warm up while driving at low speed in my driveway and parking lot. Some of the Japanese hypermilers choose to sit and let it warm up before driving feeling this allows the low rpm warm up condition to keep the car in the more efficient range as it prefers to do anyway.

[darelldd]

<div class='quotetop'>QUOTE(efusco @ May 7 2007, 08:12 AM) [snapback]436841[/snapback]</div>

This is debatable. I chose to let it warm up while driving at low speed in my driveway and parking lot. Some of the Japanese hypermilers choose to sit and let it warm up before driving feeling this allows the low rpm warm up condition to keep the car in the more efficient range as it prefers to do anyway.
[/b]

I admit that I don't follow the hypermiler info very closely! Just from my own experience, I find that moving while running the ICE nets me a better first couple of mileage bars than leaving it parked while running. Of course I don't meter my actual gasoline that closely, and I'm guessing that the hypermilers do? Or are they taking the car's word for this stuff as well?

With very little load on the ICE, I don't see why it would be in the most efficient operating range when allowed to sit and spin.

[pola]

<div class='quotetop'>QUOTE(darelldd @ May 7 2007, 09:08 AM) [snapback]436834[/snapback]</div>

If you use EV mode to drive 2 miles below 30mph... you are wasting gas. EV mode should not be used to travel ANY sort of significant distance if FE is what you are after. If you are just crawling around a parking lot, or around your garage/driveway, it is a great time to use it (as the running ICE cannot be efficient in those situations). If I start cold and know that I'll be sitting still at an intersection after a few hundred feet, I'll use the EV button so I'm not just parked there with the motor running.

Other than these very low-speed, very short distance situations, leave the EV button alone. Using the battery at every chance you get will certainly reduce your FE.
I wanted to add here - let it go through the normal warm up WHILE DRIVING. Don't just sit there and let it "warm up."
[/b]

Darrell,
I could not find a contact link on your site to email you . Please let me know where to look for the link.
Thanks,
pola

[efusco]

<div class='quotetop'>QUOTE(darelldd @ May 7 2007, 10:22 AM) [snapback]436844[/snapback]</div>

I admit that I don't follow the hypermiler info very closely! Just from my own experience, I find that moving while running the ICE nets me a better first couple of mileage bars than leaving it parked while running. Of course I don't meter my actual gasoline that closely, and I'm guessing that the hypermilers do? Or are they taking the car's word for this stuff as well?

With very little load on the ICE, I don't see why it would be in the most efficient operating range when allowed to sit and spin. [/b]

They're using things like CAN-View, the Super-Midi and other devices to monitor fuel consumption for the trip/first mile, etc. Remember that the consumption graph is a very weird little meter that's fine for looking at trends, but not the best for showing actual vehicle performance if you're alternating speeds, and doing other techniques.

And, again, I prefer to drive rather than sit too, but I try to get out of Stage I before I have to get up to traffic speed if at all possible and that takes 30-60 seconds (usually) of speeds generally below 20mph and gentle accelerration to avoid heavy battery drain.

[JimboK]

You guys are helping me validate what I think is the right approach with my cold ICE startups.

I have two a.m. commutes: one from my fiancee's house and the other from my landlady's. My fiancee's driveway is about 500' long, level at the house and then gradually sloping downhill. I begin moving right away, with gentle pedal until I hit the downhill portion, then allowing a regen coast onto the road. With stage 1 shortened by the block heater, by the time I get to the road it's usually in stage 2 and ready for full ICE power.

My landlady, on the other hand, has a mostly uphill, quarter-mile driveway. The first segment of ~200' is especially steep. When I try to start moving in stage 1, it often pulls the battery down two or three bars. So I sit until it enters stage 2 ICE cutoff. With the block heater that may be 30 seconds or so.

Thoughts?