Do 'EV Mode' Mods improve your gas mileage?

[largomike1]

I'm interested to see what your experience is with these EV Mode modifications. I'm wondering if these mods are worth the cost, installation time, and concern over warranty issues. Please offer your opinions regarding any of these issue:

Should I be concerned over warranty issues?
Has anyone damaged their battery using this mod?
Did anyone break anything during the installation process (besides your back)?

Thanks!

[efusco]

Mike, there are tons of threads, including a recent one, on this subject. Used properly you might realize a 1-2mpg improvement in fuel economy depending on the type of driving you do. No way you'll see better than that.

Used improperly it'll make your mileage worse...and it could be significantly worse.

No one's reported a warranty issue, but if something goes wrong with your HV ECU or your HV battery and the dealer sees the EV button and decides to make an issue you could have a fight on your hands.

I've not heard of any serious damage due to the install and never heard of a battery problem related to the EV button.

[largomike1]

Originally posted by efusco@Feb 16 2006, 05:30 PM
Mike, there are tons of threads, including a recent one, on this subject.  Used properly you might realize a 1-2mpg improvement in fuel economy depending on the type of driving you do.  No way you'll see better than that.

Used improperly it'll make your mileage worse...and it could be significantly worse.

No one's reported a warranty issue, but if something goes wrong with your HV ECU or your HV battery and the dealer sees the EV button and decides to make an issue you could have a fight on your hands.

I've not heard of any serious damage due to the install and never heard of a battery problem related to the EV button.

[snapback]210695[/snapback]

Thanks for the reply. I've been searching around for a Poll result for this topic, and couldn't find one, that's why I posted it. As I'm a newbie here, I probably didn't look in the right place. BTW, I love this site, and have learned alot here.

[efusco]

Originally posted by largomike1@Feb 16 2006, 03:42 PM
Thanks for the reply.  I've been searching around for a Poll result for this topic, and couldn't find one, that's why I posted it.  As I'm a newbie here, I probably didn't look in the right place.  BTW, I love this site, and have learned alot here.

[snapback]210702[/snapback]

There are no polls, which are fun but worthless for factual data.

[TonyPSchaefer]

I marked "uncertain" mostly because I've only gone through one tank with the button and there was a swing in temperature that could account for the swing in mileage. But I'm really hoping to debunk Evan's "1 -2 MPG improvement at best" claim!

(a man can dream)

[jwe8f]

Think of an EV switch as a way to keep you from unnecessarily DROPPING your MPG. For instance, from unnecessary idling (like at a drive-thru), or running the engine at all at the end of a trip when you are driving at slow speeds.

Beyond that, it mostly has a 'coolness' factor, where you can drive past your neighbors or co-workers with the gas engine off.

All that said, it has a minimal impact on overall gas mileage.

[darelldd]

Originally posted by largomike1@Feb 16 2006, 01:19 PM
Should I be concerned over warranty issues?
Has anyone damaged their battery using this mod?
Did anyone break anything during the installation process (besides your back)?

[snapback]210687[/snapback]

OK, who voted "better than 11 mpg?"

Warranty: No, you should not be concerned. This feature is on all the cars that are NOT sold in NA. I haven't heard of a single battery problem resulting from this, and for the life of me, I can't imagine how it could impact the life of the battery. The battery in the Prius is treated like gold, and is handled by the BECU with kid gloves.

Breaking things: I only drew blood on one knuckle, and screwed up one (disposable) pin before I figured out what I was doing wrong). Beyond the pin problem, the ENTIRE project took 40 minutes including disassembly and reassembly of the dash, and cleaning all parts thoroughly before reassembly. If I did it again, I'll be I can do it in 25 minutes.

And as for cost... it cost me nothing. I used wire I already had, and used the high-beam mod. The ONLY thing I supplied was 4' of wire, and solder. Other than disabling the beeps, there aren't many cheaper mods!

And finally to the question of the thread.

I most certainly save gas with my use of the EV button. I'd have to. But bigger than that is the pollution and wear and tear that I save. Why am I so confident that the EV button is saving resources and pollution? Because I only use the EV mode to shuffle my car around the driveway or in and out of the garage. In these instances, warming the ICE does nothing any good. Burns gas for no reason, and makes the most pollution that the car ever spews. I avoid that every time I need to move the car 20 feet - all because I have the EV mod installed. Pathetically enough, the ability to run in EV mode was what clinched our decision to buy a Prius. I personally had trouble justifying a gas car any other way.

[HTMLSpinnr]

I use mine in three cases, but am unsure of actual impact:

1) Taking my daughter to the bus stop when we're running a tad late - it's .1 mile and not worth firing up the gas engine for
2) Putting car in and out of garage or jockey position w/ the other Prius
3) When driving from my office to our data center which is literally down the street. Driving because trunk is full of servers and that'd just look odd dollying them down the sidewalk ;-)

In this case, I'm doing emissions a favor by saving the cold-startup time, and gas mileage a favor by not running when not needed. Now if only the EV switch could cancel the coolant warmup period, it'd be even more effective.

[largomike1]

Originally posted by htmlspinnr@Feb 18 2006, 02:15 AM
I use mine in three cases, but am unsure of actual impact:

1) Taking my daughter to the bus stop when we're running a tad late - it's .1 mile and not worth firing up the gas engine for
2) Putting car in and out of garage or jockey position w/ the other Prius
3) When driving from my office to our data center which is literally down the street. Driving because trunk is full of servers and that'd just look odd dollying them down the sidewalk ;-)

In this case, I'm doing emissions a favor by saving the cold-startup time, and gas mileage a favor by not running when not needed. Now if only the EV switch could cancel the coolant warmup period, it'd be even more effective.

[snapback]211659[/snapback]

Thanks to everyone for your feedback. I see how / when it makes sense to use it.