How does the EV mod affect your mileage?

[stomsf]

Just wondering for those who have/use the EV mod -- do you see a marked improvement in your fuel economy?

[seasalsa]

<div class='quotetop'>QUOTE(stomsf @ Nov 12 2007, 04:04 PM) [snapback]538619[/snapback]</div>

Just wondering for those who have/use the EV mod -- do you see a marked improvement in your fuel economy?
[/b]

No. It is nice to have at times but no marked improvement.

[TonyPSchaefer]

The EV button is not designed to boost your mileage. Period.

In fact, if used improperly, you will most definitely ruin your mileage. Here's an example: let's say you're cruising along at 25 MPH. Seems like a great time to use the EV, right? Let's hit it. Now we're zipping along all stealthy like. Uh oh, we've depleted the battery and now the EV has disengaged. Here comes a stop light that just turned red. We have to stop. And wait. And all the while the engine is running. Why? Because it's trying to recharge the battery that we just depleted. Okay, the light's red now. Better, right? Wrong. Now that we're accelerating with a depleted battery, our instant mileage is even worse.

Of course, that scenario will play out for about a couple miles until the battery gets back up to about 50% SoC. At which time we punch the EV button again. D'oh!

[Tideland Prius]

Rather than boost mileage, it's meant to curb mileage loss. IOW, instead of losing x mpg, you'll probably lose x-y mpg.

[blamy]

When I have green bars on the battery indicator and at a stop light I use the EV mode. Feels good to do it but I do not see any real gas mileage increase.

[9G-man]

Short answer, little-if-any MPG increase, and very possible MPG reduction.

Another way to look at it, there is often a big opportunity cost to using the EV switch. Liberal use of the EV switch will often end up hurting overall MPG because it robs you of future ICE off, stealth and glide opportunities that would have given a better mileage return. (having lowered battery SOC, and forcing ICE on/increasing it's output.)

Here is another example. I can leave the parking lot at work and drive EV mode for about a half mile, to the interstate on ramp. Then drive home via interstate. The result is 5 min. consumption bars of
50/45/60 MPG for 15 minutes. . If I don't use Ev the bars are 25/50/70 MPG. The end result actually is still in favor of EV, but you can see how it's use impacts second and third segment MPG.

And 1/2 mile of EV can ruin 2 miles of stealth and glide.

That being said, the Gee-Whiz factor is very high and I think I've learned to use it at the right times. Possibly I've seen 1-2 MPG gains since I've learned when to use it. It allows me reposition my car in the parking lot at work, without starting up, and I can reposition my car in/out of the garage for washing etc., without starting up. I can also force a stealth or glide with the EV switch under proper conditions that ordinarily would not have been allowed. One such example is during rush hour, and being stopped just prior to an uphill crest, that I know will be followed by a long downhill glide/regen. I can use EV switch to force a stealth that would have otherwise been impossible over that crest, with no cost on the downhill side. I think I just saved a little gas.

I think I can midigate the downside of EV switch use by limiting the battery SOC that I EV down to .

Worth the time and effort in my book..

[MikeSF]

<div class='quotetop'>QUOTE(TonyPSchaefer @ Nov 12 2007, 06:06 PM) [snapback]538659[/snapback]</div>

The EV button is not designed to boost your mileage. Period.

[/b]

Curious scenario here, maybe somewhat unique.

I live on a hill, it's residential streets to the bottom of the hill to the freeway for work, however the ICE flips on and I get at best 20-25 mpg as it warms the car up on what ordinarily would be "free miles". Is the lack of a warm engine on a freeway going to negate any "free miles" I get with an EV flip for the downhill cruise?

[qbee42]

<div class='quotetop'>QUOTE(MikeSF @ Nov 15 2007, 12:43 AM) [snapback]539839[/snapback]</div>

Curious scenario here, maybe somewhat unique.

I live on a hill, it's residential streets to the bottom of the hill to the freeway for work, however the ICE flips on and I get at best 20-25 mpg as it warms the car up on what ordinarily would be "free miles". Is the lack of a warm engine on a freeway going to negate any "free miles" I get with an EV flip for the downhill cruise?
[/b]

Either way you are going to have to warm up the engine, and it appears that modest speeds are best for this. I suspect you are not gaining much if anything by using EV mode down the hill, unless you are doing a lot of sitting at lights.

Tom

[mparrish]

<div class='quotetop'>QUOTE(MikeSF @ Nov 15 2007, 12:43 AM) [snapback]539839[/snapback]</div>

Curious scenario here, maybe somewhat unique.

I live on a hill, it's residential streets to the bottom of the hill to the freeway for work, however the ICE flips on and I get at best 20-25 mpg as it warms the car up on what ordinarily would be "free miles". Is the lack of a warm engine on a freeway going to negate any "free miles" I get with an EV flip for the downhill cruise?
[/b]

The short answer to this thread's question is the following:

(1) If you do not "hypermile", the EV switch will not give you much of a boost.
(2) If you do "hypermile", the EV switch will give you a 10-15% mpg boost (over a typical 10-15 mile city trip).

Your situation is similar to mine. I also live at the top of a hill, and before the EV switched endured low iMPG during warmup as I made my way down the hill. With the EV switch, I'm able to kill the engine as I go down the hill. My mileage got a 10-15% permanent boost on my commute to work.

The EV switch is sometimes jokingly referred to as an "engine veto" switch. That's a more appropriate name, in that activating the switch only kills the engine. The switch allows you to begin a P&G cycle in stage 2 & 3a, effectively allowing you to warmup up the car at times (uphill, pulsing) when you would have had the engine on anyway and to turn it off at times (downhill, gliding) when you'd prefer not to have it on.

Yes, you have to warmup to 180F+ anyway. And yes, using the EV switch to P&G right out of the gate after stage 1 does delay that warmup until you are farther down the road.

But the costs of doing that are more than outweighed by the benefits of P&Ging right out of the gate after stage 1 warmup. Ask anyone who hypermiles with the EV switch and they will till you. My city commute in the summer went from ~70mpg to ~80mpg overnight, and there it stayed.

If you say "no thanks" to hypermiling and are only interested for the potential MPG boost, then you can probably not bother.

Edit: I should point out something very, very, VERY important. I use my EV switch ALL THE TIME during stage 2 & 3a warmup. It helps my mpg significantly. HOWEVER, I never, never, NEVER drive in electric only. You won't see yellow arrows on my screen, only a blank screen or green arrows. Yellow arrows is bad for mpg. But the switch is great provided you just use it to kill the engine.

[ServoScanMan]

<div class='quotetop'>QUOTE(stomsf @ Nov 12 2007, 06:04 PM) [snapback]538619[/snapback]</div>

Just wondering for those who have/use the EV mod -- do you see a marked improvement in your fuel economy?
[/b]

I'm not sure what your defintion of 'marked' is. My fuel economy has improved with the EV mode switch.