EV prius button???!!!

For those who live in the Northwest there is a Toyota Tech in Olympia who will install the EV mod for you for about $120.

 

Just in case the above has not already made it clear, the Prius already has all the programming to support EV mode. They just didn't put the button in the North American model. Probably because of EPA testing: any user-controllable option would confuse the EPA testing protocol, or, alternatively, if the driver can control the EV selection, the car might not respond exactly as in the EPA tests. (Which it doesn't, anyway!)

The only thing these mods do is allow you to access a function already built into the car.

However, it has very limited capability. EV can only be used under 34 mph, when acceleration is light or none, when the battery SOC is at 3 bars or more, and when the battery temperature is adequate. After a relatively short distance the battery will discharge below allowable levels. Any time the car falls outside the permitted conditions, you'll hear three fast beeps and the car will go back to normal operation or refuse to go into EV mode.

So calling this "an all EV option" is rather stretching a point. It's more of an occasional EV option.

I use mine in a very similar manner as Evan uses his. Sparingly, under certain limited conditions. Mostly, it's fun to have the added control over the car. Mostly, it's a really fun toy. I'd rather have had the button, but I was scared to try that mod, so I bought the Costal Tech version, which is relatively easy to install.

 

So... after you added the ev button, how much improvement in MPG did you experience?

 

<div class='quotetop'>QUOTE(busyrosy @ May 1 2006, 12:33 AM) [snapback]247843[/snapback]</div>

Difficult question because it depends on so many factors: driving conditions, length of commute, number of hours per day driven, how well you understand the button's best uses, etc.

When I lived in Fargo, my drive was very short. In winter the engine did not begin to get warm until half-way through my drive, and the battery never got warm. Under these conditions the car seldom goes electric on its own, and the battery sits near its upper limit and is not much used. In slow city driving (under 34 mph) the EV switch allowed me to make use of the battery, and I believe my mileage improved by several mpg.

However, once the battery reaches about 80 degrees the car makes much more use of it, and above 100 degrees it goes electric very easily. Under these conditions I would not expect the EV switch to make much difference at all. But it's still cool to be able to glide silently through parking lots, and to shut off the engine a few blocks before arriving at my destination. It's also nice if you are just going to move a cold car a short distance, to be able to prevent the engine from starting.

(Note that HV battery temperature, refered to above, can be seen only if you have installed the CAN-View, an aftermarket device that allows you to see a dozen or so parameters not shown on the native MFD. In Spokane's present mild temps, it takes about a half an hour of driving to get the HV battery nice and warm, and once warm it stays fairly warm for most of the day. I didn't have the CAN-View when I lived in Fargo, so I don't know how long it takes in extreme cold weather.)

 

<div class='quotetop'>QUOTE(busyrosy @ May 1 2006, 12:33 AM) [snapback]247843[/snapback]</div>

YMMV. It depends on your use. For some there is an improvement, for others it'll go down. Don't forget that the battery is charged by the ICE, so it may run longer just to replace what was used in the EV mode.

I use it on the way home from work after the car is warm and I'm going to the nearby grocery store. I get in, power up and activate the EV mode. I can easily get home without having the ICE kick in.