Finally added the EV mod

I just added the EV button to my new Prius and am now going to wait until I finish with this (nearly full) tank before using it extensively to see if there's any difference in average MPG.

My plan is to use it when accelerating from nearly every stop instead of babying the pedal (when that will tick off people behind me,) and to use it when the system won't let me glide at lower speeds in the earlier warmup stage(s). The rationale is that electric motors are WAY more efficient than ICEs overall, so to force the car to use its most efficient power source during its least efficient operation (acceleration) should yield at least a noticable MPG increase.

Later I plan to add a charger so I can charge the HV battery to nearly 100% from the wall. This in conjunction with judicious use of the EV mode should make an appreciable difference. (The system favors electric motor use more and more as the battery charge goes up from 5 bars. To maximize this, I would want to use EV mode as much as I can at the end of my trips so the SOC is as low as possible so more charge comes from the wall instead of the ICE.)

Whacha tink?

 

The single biggest thing that makes my mileage higher than it otherwise has to be is short trips. If I drive for only ten minutes many times a tankful, I get ~20% more consumption. That's a big problem that's hard to overcome. Short trips use less gas overall but more gas per mile. I definitely try to plan my routes/errands so that the engine is warmed up as much as possible before I make my first stop.

If I don't have any short trips I consistently get ~4.6 L/100km a tank or 51 mpg US.

I recently installed the EV mod from Coastal and it works fine - I'm on my first tank with it and have currently 4.4 L/100km (54 mpg US) at ~200 km

I know that if I use it incorrectly it will increase my car's fuel consumption. I only plan to use it in situations like the OP described - where a series of traffic lights are strung close together and are often red ; or when leaving my neighborhood which is a few blocks from the freeway. Once I'm on the freeway I'm going down a large hill so I can easily replenish my battery.

I also don't like the ICE coming on shortly after starting up the car when I can't get moving into traffic right away. I prefer to get moving before I let the car heat up the cat converter, hoping this doesn't lead to too many unnecessary emissions, considering that I'm babying the accelerator then.

Lastly, of course, the EV is good in parking lots but it's only necessary then when the car is cold. Otherwise the ICE is almost always off there anyway.

Cheers

 

<div class='quotetop'>QUOTE(JimboK @ Jul 8 2007, 06:47 PM) [snapback]475217[/snapback]</div>

...Which makes me think Toyota could have done better with the algorithms. If I was designing them, I'd want to give preference to the electric motor (ESPECIALLY during acceleration, which means using the motor's full potential (momentary 200% torque)) and use the ICE more for generation rather than propulsion (i.e. make it behave more like a series hybrid.) It seems Toyota's focus was more on emissions than fuel economy (which makes a difference as evidenced by the system's running the engine just to keep the exhaust system warm. I wonder if they considered electrically heating the cat converters?) Cost I'm sure was also a factor, since allowing the motor to do what it's capable of would drain the battery pretty quickly and a larger battery costs more.

Actually, they add batteries to get an acceptable all-electric range. The stock battery is only good for 2 miles or so even if used fully. However, it can definitely handle larger cycles (see the Toyota RAV4 EV which uses similar NiMH batteries,) with some decrease in cycle life. But if the current algorithms allow the battery to last >200K miles, why not be more agressive with the fuel economy if it meant even only 100K miles when replacement is <$2000? At 4 cents/mi including grid power, you're still saving over gas! I'm sure Toyota just wasn't taking _any_ chances with the battery so as to offer the long warranty and not lose money or face on it.

 

Gas mileage improvement:

I recently filled up and have to take my wife downtown three days this week. The good thing is that I can operate in all-electric mode just about the entire time I'm downtown (2 mi roundtrip from the on/off ramp.) My MFD shows just under 60MPG as a result!

Here's what I do:
1) EV mode until I get to a longer stretch (.5mi) when I can let the engine warm itself while moving the whole time (~30MPG)
2) Regular mode onto the highway for about 10 mins, pulsing & gliding sortof the whole way (charges the battery back up by the time I have to exit.) Doing 60-70MPH. 35~99 inst. MPG depending on hills, probably ~52MPG avg.
3) Exit, hit the EV switch when stopped at the light. Accelerate gently with traffic through 7 more lights & 3 turns, etc. 99.9MPG.
4) Kill EV on a longer stretch (.25 mi) nearing the highway (charge up a bit) ~35MPG.
5) Start EV again to accelerate onto the highway until >34MPH when it kills itself.
6) Recharge while P&G-ing back home.

(For San Antonians, I get off IH-35 N at Durango, hit EV switch at that light. L on Flores, R on Houston, R on St. Mary's, L on College, L on the next street, L onto Houston again, L onto Flores, kill EV after Commerce to get a bit more charge (~1.2mi EV at this point), start EV at Durango, R on Durango, L on Pecos La Trinidad back onto IH-35 S.)

P&G makes the most MPG difference. I find that the car's accel pedal is more of a torque than speed control. That is, if you've gotten to your desired speed and the engine is still revving (& MPG is <45,) back off the pedal completely, then press it a bit again. (It seems the computer needs to be told to reevaluate the gear ratio and this is how you tell it.) You'll notice the MPG shoot up to >50 and your speed will stay about the same. This applies on the highway as well as in stop & go traffic. (You just won't glide on the highway as easily since the engine has to spin.)

 

<div class='quotetop'>QUOTE(JimboK @ Jul 8 2007, 07:47 PM) [snapback]475217[/snapback]</div>

I think this is the key part most people don't understand. The electric motor is recharged by gas and just a little by regen braking. The conversion from gas to electric is not 100% efficient. So unless you drive downhill both ways or are very heavy on the gas pedal (causing regen), using electric is a net loss.

The computer may be smart enough to know how much electricity was generated by everything other than ICE and let you use only that much battery and maybe a little more for warm up and anything else that would make the ICE more efficient..

 

Hi Jim,

Looks like a button to fire a missile or detonate something!

 

Hey everyone,

First off, Jimbo - nice detonator button!

Well, I finally built up the courage to tackle installing an EV button after pondering it for a long time. Rather than create a new thread, I thought I would share my experience here.

First, I printed and followed Dr. Evan's 2004 instructions, and they worked like a charm, though I did encounter two anxious moments... more on that in a minute. In any case, the whole job took me just over 2 hours, and seems to work like a charm now.

First, I opened up the steering column to harvest a few pins. As Evan explained it was a bit tough to get the two covers separated, but I found a gentle squeeze on near the seams seemed to help, without needing any metallic tools, thus no damage.

Using my paperclip, I managed to work two pins out, though I only needed one in the end. I think I will tape the second one to the inside of the console lid in case I ever need it.

Getting the glovebox out and vent covers was no problem at all. Unplugging the ECU plug was fine, easy to identify the proper receptacle thanks to the great documentation.

I soldered the pin to one piece of 14awg speaker wire I had hanging around. After some anxiety, I finally decided to plug it into the ECU after triple checking to make sure it was the right hole. A very tight fit (solder didn't help, of course), but used the jeweller screwdriver to push it down, praying I didn't fray/slice the wire in the process. Feeling nervous about cutting any factory wires, I tried looping the ground wire around some big 12mm bold below the vent, that seemed part of the frame(?).

OK, time to test it out, before I go any further! I take a deep breath, put the car in Ready, and touch the wires together. Nothing different, but the car also doesn't report anything wrong, so I didn't break anything. (phew!). Hmmmm...

I wonder what the problem is. I pull the ECU plug out, push the pin some more, put it back in. Same thing. Start checking the ground.

No change. Starting to stress.

I decide to use one the taps I have and tap the black & wire pin 1 wire. Same thing, but then something dawns on me; each time I pressed it, I did notice it switched to the Energy screen, but I was expecting a beep or some kind of message about EV mode to appear, but I never got it (and also always killed the ignition before the 7 seconds so it never started when it "failed").

Anyway, to make a long story short (too late, I know), it was working, I guess 2006 (+?) doesn't beep when EV engages. Who knows, maybe this is a wrong assumption, but that is what I expected based on what I had read in the past.

Anyway, now I am pumped that the hardest part is done and it is working!

Now I just need to fish the wire over and install the button.

Problem #2. I taped the wire to a straightened coat hanger and started fishing. I got it through fairly quickly, but it was pretty low down at the steering side. So I tried to pull it back, only to end up getting it stuck somewhere in the middle. Big mistake. I spent the next 45 minutes trying to untangle it and get back to square 1. I eventually did it, but it was not easy. Another 15 minutes or so and I finally got it through, I pulled it through the button hole, drilled my blank 1/2" for the Radio Shack (or "TheSource") button, installed it closed it all and up and case closed! Very exciting!

*** That's all for the installation, now for a personal story about my experience today.

Anyway, took it for a test drive as I went to pick up my wife, showing off what I can now do my with my new toy. As luck would have it, I was EVing away from where I picked her up, and the timing was perfect as I reached purple bars at precisely the same time I reached a level crossing where the signals just started. Yeah, I was then sitting there, ICE idling, wasting gas and watching a train go by. Oops. Ah well.

But then, for the next hour or so we did a bit of shopping and everytime I hit my EV button it kept telling me "Can't enter EV mode" - even when I pressed it immediately after starting and before the ICE engaged. Battery was 7/8 bars (blue), so State of Charge (SOC) wasn't the problem. The temperature was about 22C(~80F), which was not extremely warm, but it was a bit humid.

Once our errands were over, we got back on the freeway for a short while (~10 mins), and once I got off again back in the residential territory, it seems the EV button is working fine again.

From my knowledge, the only conditions that prevent EV from engaging are SOC being too low, initial warm-up already started, or battery temperature either too hot or too cold. Since it wasn't either of the first conditions, I presume it had to be #3, possibly since I had just drained it down to purple and it had just been recharged...?

Anyway, just thought I would share my experience, and if anyone has any comments as to why EV wouldn't engage for an extended period as described, I would be happy to hear them.

Thanks and sorry for the long post!

PS - I also just updated my sig.

 

Yes, that is true, however in this case I was parked. I had just put the car into Ready mode and immediately pressed the EV button before the engine kicked in, and it denied me multiple times over a half hour period or so, I tried each time I got stopped at a light.

However, once I got on the highway or a short jaunt home, it was working fine again once I got back down to lower speeds again.

Bizarre... like I said, I guess battery temp must have been the reason...? I don't have a ScanGauge or anything to know for sure.

 

Just a follow-up since my install 5 days ago;

I haven't had an "unexplained rejections" of EV mode since the first day - only when battery charge was too low (i.e. 3 bars or less) or speed was too high, as expected each time (just checking/testing). It always engaged immediately after startup as long as the battery SOC was decent.

I really like having the added control of delaying the ICE startup. Since I live in a townhouse complex - and often have to wait for traffic before pulling onto the busy street - I like engaging EV right away and waiting until I merge into traffic and get up to "cruising" speed before disengaging EV. I prefer the warmup to happen while the car is rolling rather than sitting idle.

Experiencing how the EV dynamic changes vs stealthing (i.e. you can accelerate reasonably quick within EV parameters vs featherfooting it in stealth), gives me a much better appreciation of PHEV conversions.

I do wish there was a way to activate that EV light on the dashboard. Once or twice this week, I engaged it then got distracted or stuck at a light or something, then hear the three beeps as it is forced out of EV due to low SOC, which of course hurts my overall MPG since it is not an opportune time to recharge. Oops! Ha ha... (I'm still in the "playing" stage, what can I say...)

Haven't had to do any car shuffles this week, but it will be handy for that too...

Cheers!

 

I have had numerous instances where EV mode does not engage. I drive every morning from my house to the train station (2.2 miles) to go to work. I always try to engage EV mode immediately. Once in EV mode, I can get all the way to the station without the ICE starting. The run is mostly level and down hill, so I only loose 1 bar on the trip. This week I could not get into EV mode twice. The SOC was higher then other times it went into EV mode, and the temperature at 6:45 is in the 60s. In both cases, once the engine warmed up, I was able to enter EV mode. It seems finicky.

 

Hmn, so that makes me wonder if the EV mod is right for me. I've been considering it because I live at the top of a short steep hill. My morning drive taking a kid to school is just a mile, mostly downhill with some flats. If EV will engage right from the beginning I could regen all the way down the hill, cruise on just a little EV to the school, then drive normally back home. Also, same story if I'm headed for the highway, regen down the hill, short flat run to the onramp, then highway speeds recharge the battery. Am I wrong? Will EV not work when the car is cold?

- D

 

Thanks JimboK! The car lives in a garage. Not heated but I doubt it'll ever see below freezing in there. Now the biggest trick for the EV switch install (I like the one from Sigma) will be relocating the PIAA fog light switch that the previous owner put in that spot.

- D

 

I tend to use my EV mod almost like the "canister hack" in that around 100F (when I can use EV MOD with a decent SOC), I put my Prius into EV mode when I am gliding. I press the button again to disengage when I want to pulse. I usually do this until I get to 159 where I can do an idle check and then get to S4. It seems to really help out on my mpg for the first 5 mins as I used to get around 25, now I see around 35.

The only downside is that when I use EV mode from my driveway to the main street, I am worried that punching the engine from a standstill ~2500RPM at a cold engine (~30F-50F) will do some longterm damage. The only reason I don't gradually accelerate onto the main road is that it will draw anywhere from 60-90 amps from the battery and lower my SOC by at least 3%, but if I punch it to around 2500 RPM it will use the ICE solely which also helps to warm the engine up quicker.

Is any of this post a good idea or should I not use the EV button in this manner? Any comments would be appreciated. Thanks!