Prius  -  How It Works


Last Updated: Sun. 12/07/2008


Just Drive It.  You don't really need to know all the things the Prius hybrid-system automatically does for you.  But if you're curious, the touch-sensitive multi-display on the dashboard provides all the information you need.  Below are photos what you'll see, along with an explanation of what it means.


DETAILS  is a webpage that expands this one, providing more technical illustrations & descriptions for each hybrid system mode rather than referring to the Multi-Display.


ANIMATIONS  is a webpage you'll want to explore once you read through the information here.  It provides moving versions of the photos below, allowing you to see the various modes on Multi-Display in action.


Classic Prius


Iconic Prius


Stealth Mode   or   Battery Drive

All thrust is provided by the electric motor and all power is provided by the battery-pack.  To be considered "stealth", the gas engine must not be running.  That dead quiet characteristic causes the car to sometimes drive by unnoticed, hence the term "stealth".

From a complete stop, the Prius can accelerate to and sustain up to 42 MPH.  Momentum pressure, like an incline or quick acceleration, will cause the gas engine to startup and engage (ending your electric experience).

At speeds above 42 MPH, battery-only driving is possible when you go down a hill.  The electric motor will sustain your speed, even at 70 MPH on the highway.  This allows the engine to idle (which uses less gas) or just spin (which doesn't use any gas at all) until it is needed to propel the wheels again.

The sample on the right also shows the "green" charge level, which can occur anytime while you are driving.


Regeneration Charge

As you approach a stop or just slow down, the excess kinetic energy is used to turn the generator.  This creates electricity which is used to charge the battery-pack.


Engine & Motor Drive

Did you know the battery-pack isn't always needed for the electric motor to work?  When you accelerate moderately, the engine can provide all the electricity the motor needs.

If the battery doesn't need to be charged while you're driving on the highway, this mode occurs.  The electric motor provides thrust along with the gasoline engine.


Engine Drive + Charge

This sight is quite common while your cruising down the highway.  The engine provides thrust for the wheels along with electricity for charging the battery-pack.


Engine & Motor Drive + Charge

Ever wonder why Toyota calls this technology: "Prius | Genius"?

This mode is why.  As you are driving down the road, the system will automatically detect this ideal situation.  The engine will provide thrust to the wheels as well as electricity for both feeding the motor and charging the battery-pack, all at the same time.


Full Power   or   Gradual Slowing

Both rapid acceleration and moderate deceleration take full advantage of the hybrid system to achieve maximum efficiency.


Motor Drive & Engine Charge

When you shift into reverse and the battery-pack needs to be charged, you might see this.  The reason the gas engine doesn't turn the wheels backward is because it wasn't designed to.  The transmission does not have a gear for reverse. All thrust is provided by the electric motor.

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Startup Charge

When you first startup a Prius, you'll typically see this before you shift into drive or reverse.

The sample on the left also shows the "half" charge level, which can occur anytime while you are driving.

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Stopped   or   Gliding

When you come to a complete stop, you usually won't see any energy flow.  This can also happen when the Prius is gliding.

The sample on the right also shows the "pink" charge level, which can occur anytime while you are driving.

Battery-Pack SOC (State-Of-Charge) Indicator

The amount of green inside will change based on how much electricity is available.

On the left, the two states displayed to the left indicate approximate charges of 3/4 and 1/2.  (The "full" amount covers the - and + symbols, filling the battery all the way to the top.)

On the right, there are 8 bars that indicate charge-levels.  When there are 7 or 8, the color is green.  When there are 3, 4, 5, or 6, the color is blue.  When there are only 1 or 2, the color is pink.  This use of color makes noticing the charge-level changes much easier, no need to have to count.



Speedometer, Gear Select, Odometer, Fuel

This display provides the traditional information that people need when driving; however, it is in a non-traditional place.

Located up near the base of the windshield, you may find it awkward at first.  But like many Prius owners, you'll end up quite pleased after you discover how much easier it is to look over rather than down behind the steering-wheel and your hands.  And some people can see this display using just peripheral vision, so they don't have to remove their eyes from the road at all.



Besides the "Energy Monitor", the "Consumption" screen is also available.

By switching to this, you get a graphic MPG summary of the most recent 30 minutes of driving plus the MPG you are getting at that exact moment.  In text on the bottom, the average MPG for the miles driven since the last time you pressed the "Reset" button is shown.


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