What This Button Doesn't Do

Our series of posts titled "What Does This Button Do?" has been quite popular, revealing the true nature of various peculiarly labeled buttons in new cars and trucks. Today's entry, pictured above, takes things in an unexpected direction. What does this button do? Absolutely nothing!

As I explain in my 2012 Toyota Prius review, the button is found on the venerable Prius and some other Toyota and Lexus hybrids. Unlike the other buttons we've highlighted, its function seems clear: EV equals electric vehicle. It's meant to activate an all-electric EV mode that allegedly allows for gas-free acceleration. Only it doesn't.

The EV mode is purported to raise the threshold at which the gas engine kicks in, but it's nothing like the Chevrolet Volt — which runs electric-only under full acceleration — or even the Prius Plug-In, which gives respectable electric acceleration to 60 mph. Prius owners will argue furiously that they drive all-electric all the time, up to about 30 mph. Maybe — downhill, with a stiff tailwind or with no one behind them. In actual traffic, these are the people you want to pull from their cars and beat with a soy burger.

In my experience, the Prius accelerates solely on electric power less than people seem to expect, but turns the engine off far more frequently than you'd imagine when coasting. Ultimately, what matters are the results, and here the Prius consistently delivers, with an EPA estimated 50 mpg combined. But the EV mode button? A ruse! It belongs in the same category as an elevator's "close door" button. I like to imagine that when you push the EV button, somewhere an elevator door closes. …. If not, well, it's just taking up space.

See More Curious Buttons
2012 Toyota Prius Review
2012 Toyota Prius Video



If you learn how to drive the Prius correctly, then the EV button is useful (inching along in traffic, driving through parking lots, etc.). Of course it's not like the Volt; it's not supposed to be. Perhaps, that's why the Prius costs almost $15K less.

Paul Graham

I want to know, Why bother? My old 2006 Jetta TDI gets 50 Mpg if I try, 40 when I don't and when running waste oil, is carbon neutral. Why spend that much money on a dog?
And - Why don't they make electric/TDI or clean diesel hybrids?


Obviously written by a person who doesn't do his research. The EV button on my Prius plug in does work and works well. What it doesn't do is stop you from getting the acceleration you need when you need it. If you step on the gas hard the gas engine will override as a safety feature. When I drive to work I end up doing about 90% in EV mode and 10% with gas, due to rapid acceleration. My wife on the other hand who works closer and in a less congested route can do the full thing EV. You should do more research before you beat someone with a soy burger or even review something you are unfamiliar with.


John, the writer is not referring to the Prius Plug-in, but rather the hybrid. I thought that was made pretty clear in the article. I have had two prius' in the past 3 years, and I think the author is more right than wrong here. The car is already programmed to switch to battery in most the same circumstances where you can actually use the EV mode. I, have often found EV mode to be useless.


Ride a motorcycle, even my Concours 14, which has a slightly de-tuned Ninja motor (supersport tourer) in it, gets 42 mpg minimum (average)! My other bike gets around 50.

Matt Randall

Until they make a volt like 4x4 I am sticking with my '98 Land Rover Discovery. All 12 mpg of it. Oh, and completely paid for and I don't drive more 100 miles a week.


Like others have said. EV mode does work. But Toyota also realized if you push the gas petal down, you want to get going, so it will override the EV mode and give you the power you are asking for.

When driving around home I can stay under 25mph and so I use EV mode and get much better then the 50 mph I get driving to work 68 miles one way.


I have a Prius, and while I agree that the EV button doesn't fully switch the vehicle into electric, I does serve a purpose when in heavy traffic you can switch over - I don't think it's a total ruse just because it isn't everything the author wants it to be. if you learn about the vehicle then you can choose to use the various options in the manner that best suits you. Regardless, any writer to inserts the notion of beating anyone over the head with anything (soy burger or not) - is establishing themselves as a not-so-credible source of information (in my opinion)

Dylan C.

The EV mode is only good for sneaking up to places or people. I consistently get 50 MPG but never use the EV unless I am sneaking up to the house to scare my wife.

Andy B.

I used EV button when I was sneaking up on Dwight Schrute, after it came to light that he was sleeping with my fiance Angela. I pinned that SOB to the fence!


I applaud you Prius owners that get such great mileage, but I think you're missing the author's point. The EV Mode would at first appear to make the Prius operate like an EV. It absolutely does not. An EV can operate at any speed under full acceleration with only electric power. No one can argue that this Prius is capable of doing that. However, it can electrically propel itself under conditions in which the gas engine would be likely to shut off anyway, but the the EV mode ensures that it does. This is more of a "super hybrid mode" rather than making it an EV.


So not having driven a Prius, can you stay all electric by being delicate with the accelerator? If so, then the button is worthless.


All the Prius modes are suggestions, not rules.
EV does not force you into electric only, Eco does not force you to drive like your grandmother, and Power does not force you to drive it like a drag racer.

The buttons do help you drive the way you intend, I drive in Eco because I want the most Economy, When I press the accelerator far enough, all the power is still there, when I get off a long stretch of highway driving, I can go over a mile on electric. And yes, EV is mostly for sneaking home late, so I do not use it often.


I tried this in a Prius. I hit EV and put the pedal to the floor to see if I could just drive with electric. NOPE. Toyota doesn't believe Prius owners want/can handle manual control of certain functions of the drivetrain, which is probably correct. I mean, they bought a Prius. #lolyoucoulveboughtaTDIbutyouretoodumb

Mark G.

I got a 2012 Prius with package 3 and in the Hybrid Systems Indicator, there is a charge section, electric eco section, a white line in between the electric eco section and the fuel eco section and then the power section. Going uphill from a dead stop, I can activate my EV mode and accelerate up the hill and go into the gas zone of the eco and the engine is still off. Now if I go into the power section pressing the accelerator, then the engine will come back on and say the EV Mode deactivated. There are times I want to put the EV on, but won't due to the batteries being too low and if they die, you got a hunk of metal and a long way to the shop unless it's a plug in. Mine is not a plug in. In normal or ECO mode, if you accelerate and the throttle bar crosses that white line from electric eco to fuel eco, the engine turns on. If the batteries are low, the engine and brakes have to charge the batteries. The EV mode works best when the batteries are more than halfway charged. The EV does work, unlike what this guy claims.

Jeanna M

Thank you, Mark G. That's all the information I wanted! I just got a 2012 Prius V about 3 weeks ago, and was curious about the buttons so I was doing a little research.

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