Installed EV Mode switch today

[Ichabod]

Originally Posted by seftonde

...raise my MPG a bit by using the EV on my final stretch of two miles...

That's actually a documented technique, so you'll find people agreeing with you. I don't really do that because I don't think the gain would be very significant. The reasoning is sound though: ICE will run during warmup anyway, so why not run the battery down at the end of the day?

Originally Posted by k2technical

...I have been told by.... the engine lubricates the gears....

EV button install could be a warranty issue. Perform that mod at your own risk. It activates a software mode that's built into the car though, so warnings about possible damage to your car may be overstated.

[offroad1994]

The real issue with the EV mod is that you take your batteries below 40% charge, and you DO NOT immediately charge them back up again (you might park your car with the engine off - thus not charging the battery). There are a few discussions about that issue. You can obviously go on battery only power, but then you need to make sure, if your batteries go deep discharge, that you do full recharge within a day.

[Ichabod]

Originally Posted by offroad1994

The real issue with the EV mod is that you take your batteries below 40% charge...

That is decidedly NOT the real issue. EV mode is a mode that's programmed into your car. It's not a hack or even a mod. The only part that's a mod is adding the button that enables it, because that was left out of the US version of the Prius. EV mode is protective of the battery and will disable if you accelerate too hard, if the battery SOC drops too low, if the ambient temperature isn't good, and probably a number of other factors.

[offroad1994]

Originally Posted by Ichabod

That is decidedly NOT the real issue. EV mode is a mode that's programmed into your car. It's not a hack or even a mod. The only part that's a mod is adding the button that enables it, because that was left out of the US version of the Prius. EV mode is protective of the battery and will disable if you accelerate too hard, if the battery SOC drops too low, if the ambient temperature isn't good, and probably a number of other factors.

Ichabod - I stand corrected. Now I remember others saying that EV MODE is very tricky and will not even activate if there is something going on with the battery charging. So then the EV switch should still be okay for the car, though it is debateable about the fuel savings.

Does anyone have the EV switch with an extra battery for PHEV mode use? Any links or reference to that?

[JimboK]

Originally Posted by TonyPSchaefer

There are a precious few people who have reported improved mileage linked exclusively to the EV button.

You think I'm precious, huh?

I can now say with confidence it helps mine. See this for more.

Originally Posted by Nords

While I appreciate that battery power is less efficient than driving the wheels directly from the engine, the car also wastes a lot of heat at startup to warm up the catalytic converter to the EPA's satisfaction. Perhaps an EV switch would avoid using a few drops of fuel for regulatory reasons... especially when the battery has enough charge to make the short trips.

And that's exactly the primary application for me, as the link above shows. Except in certain low-speed, low-demand situations, I do not use it for propulsion. Instead I use it to shut the ICE down when I don't need propulsion during warmup.

[Nords]

Originally Posted by JimboK

And that's exactly the primary application for me, as the link above shows. Except in certain low-speed, low-demand situations, I do not use it for propulsion. Instead I use it to shut the ICE down when I don't need propulsion during warmup.

I guess the next question would be the payback of an EV button.

If mpg goes from 60 to 70 for a commute of a few miles, how long does it take to pay back the cost of the EV switch and any installation costs/hassles? And are there any other unpleasant surprises, like having to explain the mod to dealers who are threatening to take advantage of the voided warranty?

[Danny Hamilton]

Originally Posted by Nords

I guess the next question would be the payback of an EV button. If mpg goes from 60 to 70 for a commute of a few miles, how long does it take to pay back the cost of the EV switch. . . .

I don't remember exactly what the Costal EV cost, but I think it was somewhere around $40.

After that the math is pretty simple.

4200 miles at 60 MPG = 70 gallons used without the EV mod
4200 miles at 70 MPG = 60 gallons used with the EV mod

70 gallons - 60 gallons = 10 gallons saved with the EV mod

10 gallons at $4 per gallon = $40 saved after 4200 miles

So if MPG goes from 60 to 70, then it will take 4200 miles to pay back to cost. (If you manage an average of 500 miles per tank, that's about 8 -and-a-half tanks)

Of course, I doubt that the use of EV will be the sole contributing factor to a long term improvement from an average of 60 MPG to 70 MPG. I'm just using those numbers because you asked.

Now if you choose the Radio Shack switch and phone wire mod instead of the Coastal one, you are probably looking at something more like $5 for the mod.

In this case:

525 miles at 60 MPG = 8.75 gallons
525 miles at 70 MPG = 7.50 gallons

8.75 gallons - 7.50 gallons = 1.25 gallons

1.25 gallons at $4 per gallon = $5.

So the mod will pay for itself with the first tank if you can get 525 miles out of the tank.

[JimboK]

Originally Posted by Nords

I guess the next question would be the payback of an EV button.

If mpg goes from 60 to 70 for a commute of a few miles, how long does it take to pay back the cost of the EV switch and any installation costs/hassles? And are there any other unpleasant surprises, like having to explain the mod to dealers who are threatening to take advantage of the voided warranty?

Danny did the math already. I installed the Radio Shack switch. Probably paid less than $5 for that and the wire together, but that number works to keep the math simple.

It's been said elsewhere but it probably bears repeating here (thanks for the reality check): There is a potential warranty issue, so it's at your own risk. At least one Prius owner initially had Toyota deny a claim for a hybrid battery problem because of his EV switch. They later relented, but not without causing some grief and insisting that he remove it. See this for more.

[gkalkas]

[quote=k2technical;661004]I have been told by the Toyota Prius certified mechanic that the software in my 2007 Prius will not accept the EV switch as in the European 2007 Prius. The suggestion from him was NOT to do it or it could harm the high voltage battery.
Plus my warantee will be void....

P.S. Then I read that the engine lubricates the gears that all the motors connect to (Synergy assembly)...and with out the engine (ICE) coming on and off, the lubrication to that will be reduced, and possibly damaged
Could that be true.....and if it is.........
quote]

I've been enjoying mine for a few years now (2005 Prius). I don't really agree with his comments. My dealer is very aware of mine and has no problem with it.

Also, you may have heard of Hymotion/A123, ready to sell their PHEV mod with their 5 Kwh battery. Now, that's a mod! Toyota said that that will NOT void the battery. But only if damage to the hybrid system was caused by the mod. In that case, however, Hymotion's warranty will pay for it. So, Hymotion/A123 is pretty sure it won't harm the car.

So re the last point, yes the system does need to be occasionally lubricated, by driving in "gas" mode. However, normal driving, even with the Hymotion mod seems to be sufficient.

So enjoy the EV mod. I've found it to save gas by using it as others have suggested, on short drives, like parking lots, etc., and using it to avoid the engine from starting purely to warm up the system.

My example is, there is a light a few short blocks from my house. When I start out, the engine would go on as I'm sitting at the light. So, instead, I go into EV at my house, until the light turns green. Then, the engine is doing its warm up, but is also driving the car.

[chrisspaulding]

.
I like the EV switch. I think it can improve MPG.

The trick is to not use it until your ICE kicks on. Otherwise, you're losing all the MPG savings in the ICE re-charge.
Instead, be mindful to stay above three bars, and creative with your EV, like on short distances, or up steep inclines, etc.

Remember, you can be in battery mode up to 40MPH just by gliding(without the EV mod), so you don't always have to use EV when you can.
I like the coasting to recharge trick too!

With good techniques, I'm of the opinion the EV can improve MPG, and it's cool to stealth your way around!!
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