Advice on Driving the Toyota Prius

Since the Toyota Prius works in a significantly different way from a "normal" car, you may have concerns about driving it.  Or, you may be in the position of test driving, renting, borrowing or loaning a Prius and are looking for some quick advice on how to get the best of the situation.  Well, Toyota seem to have gone to a lot of trouble to make the car drive like a "normal" car with automatic transmission so, first, you have nothing to worry about.  The rest of this page delves into minute detail to help you be prepared for minor differences.

Information not related to actually operating and controlling the vehicle can be found at "Owning your Prius".

Even if you're comfortable driving your Prius, I have some suggestions here on driving for fuel economy.

Starting Up and Driving Off

Before starting the car up, note the unusual position of the gear shift lever, or "running mode selector" as Toyota calls it, beside the steering wheel.   When pushed back towards the dash, this puts the car in "Park" and engages the mechanical transmission lock just as in a conventional car.   As you pull it away from the dash and down, the click-stops correspond, in sequence, to "Reverse", "Neutral", "Drive" and "Braking".  Except for the last, this should all be familiar if you've used a conventional automatic transmission.   The driver's manual explains when you have to hold the button down, but you might as well hold it down whenever you use the lever until you figure it out for yourself.

With the car in park, insert the key and turn it all the way in the normal fashion.   There will be no "rurr-rurr-rurr" of a starter motor, but the engine will start none the less.  It doesn't matter when you release the key; you can even release it before the engine starts.  If, after a while, the engine stops again, that doesn't matter either.  The car is ready to drive if the word "READY" is illuminated at the top of the instrument cluster, which is tucked under the windshield in the middle of the car.

Put your foot on the brake pedal before moving the gear shift lever.  If you want to drive forward, press the button on the top and move it three stops away from the dash.  To drive backwards, move it to the first stop.  When you take your foot off the brake pedal, the car will "creep" in the selected direction.  To go faster, press the accelerator pedal.  All of this is just like a conventional car with automatic transmission.

Driving Along

As you gather speed, you will notice another difference between the Prius and most conventional cars.  The pitch of the engine sound does not go up with the cars speed.  Instead of rising gradually, dropping as the transmission moves to the next gear and then rising again, the engine tone stays steady.  After a while, you will realize that the engine responds to how far down you press the accelerator and not the vehicle speed.  If you've driven a car with continuously variable transmission, you will recognize this feeling.  In any case, ignore it as best you can.  This is how the Prius is designed to work.  After a while, you get used to it and it starts to make more sense than conventional cars.

When you are driving at low speed on a level or downhill road, you may feel the engine stop.  Again, ignore this.  It will start up again when needed.  You can test this by pressing a little harder on the accelerator.  Because the car runs so quietly, you may actually not notice the engine stopping.  If you are interested in knowing if the engine is running, try to feel its vibration in your fingertips on the steering wheel.

If you take your foot off the accelerator pedal, you might expect the car to "free-wheel".  If it is warmed up, the engine will almost certainly stop and in any case does not contribute to "engine braking" as in a conventional car.  However, to make the car feel familiar and comfortable, Toyota have arranged things so that with your foot off both pedals, the car slows itself somewhat as if the engine were still turning over using power from the wheels.


The Prius brakes are quite sensitive.  It does not take a lot of brake pedal pressure to slow the car down.  As with any unfamiliar car, test the brakes safely before you really need them.  Although not essential knowledge for driving the car, it's worth mentioning here that when you brake, the car uses its electric motor as a generator to convert the energy of the car's motion into electricity to charge the battery (regenerative braking).  At the same time, the rear wheels are braked normally via the drum brakes and any additional braking force needed is applied at the front disk brakes.  It would be nice if this distribution of brake effort was completely unnoticeable to the driver.  Unfortunately, it isn't quite and when you first drive a Prius you might be uncomfortable with its braking.  Leave yourself a little extra room and be prepared to make small adjustments in pedal pressure to bring the car to a stop exactly where you planned.  If you own a Prius, you will get used to this eccentricity and within weeks will be able to stop the car as smoothly and accurately as any other.  The car has anti-lock brakes as standard and uses the electric motor to get the wheels turning again after a momentary lock-up.  The stopping distance of the car is extraordinarily short, so you should never feel that the brakes are in any way inadequate.

Stopping, Standing and Parking

If you want to sit in the car for any length of time, there is no compelling reason to turn it off.  The engine does not idle and burn fuel.  It may run briefly from time to time, especially if you have the air conditioner on, but it will not continuously waste fuel.  Turning the key to the "accessory" position shuts down the hybrid system and obliges the small accessory battery to supply power for anything you have turned on, such as headlights, radio, etc.  Although you will have hours of radio, the headlights will drain this small battery in little more than ten minutes.  So, you might as well leave the car turned on.  You can leave a dog inside on a summer day if you leave the car on and the air conditioner on.  Running only when needed, the engine will not waste too much fuel.  Do make sure, however, that you have plenty of fuel and that the air conditioner is properly set.  You may also have difficulty locking the car with a key in the ignition as the car might think you're locking yourself out.

When you get out of the car, it turns off any lights you had left on.  It does this quietly, without beeps or chimes.  Although this helps prevent accidental drain on the auxiliary battery, it does mean that the lights will come back on next time you drive the car.  If you don't notice, you can find yourself driving around with lights unintentionally on.

Descending Steep Hills

When you go down a long steep hill in any car, two undesirable things can happen - the brakes can get hot and your right foot can get tired.  In the Prius it takes a longer, steeper hill for this to happen.  Part of the braking is done by generating electricity so that the brakes stay cooler.  The pedal does not need much pressure, so your foot gets less tired.

In a conventional car, if you're worried about the brakes or your foot, you would change to a low gear so that the engine spins more rapidly and holds the car back, helping the brakes to slow it.  The same option is available in the Prius should you decide to use it.  If you move the mode selector lever to the "B" position, the engine will be used for engine braking.  Whereas normally the engine is stopped during braking, in this mode the computer and motor/generators arrange for it to turn over without fuel and with an almost closed throttle.  The resistance it offers slows the car, reducing brake heating and allowing you to ease up a little on the pedal.

There is no need to use "B" mode in any situation that wouldn't require a downshift in a conventional car.  The Prius does not have smaller brakes because of the addition of regenerative braking and they will not heat up any quicker than any other car.  Personally, I never use "B" mode with the exception of once when I decided I had to find out first-hand exactly what it does in order to write this.  But then, I don't live where the steepest hills are.

You may read statements that engaging "B" mode just increases the intensity of regenerative braking.  Toyota literature is not very clear on this subject and it is easy to get this impression.  My experiments, however, show to my satisfaction that engine braking always occurs in "B" mode, whatever the situation and whatever the state of battery charge.

Running Out of Fuel

Toyota caution you not to drive the Prius without fuel.  Page 88 of the 2001 Owner's Manual has the advice "It is a good idea to keep the tank over 1/4 full".  So, you should make sure you always have enough fuel to continue your journey just as in a conventional car.  If you should happen to run out of fuel, Toyota's advice is to again do what you would do in a normal car, which is to stop the car in a safe location and make arrangements for more fuel to be delivered to the car.

However, it is fairly obvious to the technically minded that if the Prius runs out of fuel there is no fundamental reason why the car should not continue to run on electric power.  Some people have thus set to one side Toyota's advice and deliberately run the car out of fuel.  Sure enough, the car keeps right along, even at 60 m.p.h. up a hill (see toyota-prius post 19074 ).  Depending on the state of battery charge, you might get many miles further before the computer shuts the car down to protect the battery.

So, taking all this into account, here is my advice on this subject.  Don't deliberately run out of fuel; other people have taken this risk for you and reported the results.  Don't, in fact, be any less careful about filling up when necessary than you would in a car without electric power.  However, if you do run out of fuel, don't panic and keep driving until it is safe to slow down and pull off the road.  Don't be alarmed by dire warnings on the multi-function display, these will go away when the car is fueled up again.  If you decide to continue driving rather than bring fuel to the car, do so slowly.  I strongly advise a speed no greater than 40 m.p.h. and if you have any distance to cover 30 m.p.h. would be better.  As far as I know (but I don't take responsibility for this), you can drive the car this way until it decides for itself to stop.  The computer will not allow you to fully drain the battery and damage it.  There is a chance that if the car does stop before you get to fuel, it will not start again.  It may be necessary to get a Toyota technician to over-ride the computer to have it start the engine.  I have not read reports of what happens in this situation.

Driving Long Distances

See toyota-prius 20497 for a drive from Oregon to Connecticut.

Last edited October 16, 2001.  All material Copyright © 2001 Graham Davies.  No liability accepted.