Driving Tips

Everyone's got their own versions and flavors of driving tips.  And yet as you look around online you'll find that most of the tips are the same.  Why is that?  It's because there are some basic truths behind proper vehicular control and efficiency.  So perhaps you will find a new nugget or two or confirmation of something you read somewhere else.

Because the single most notable feature about the Prius is its ability to achieve real-world mileage two or three times higher than the average sedan, we tend to focus exclusively on improving your mileage. We assume that any responsible Prius driver knows the rules of the road and obeys posted traffic signs.  If you have problems with those items, you will not find the solution here.

We always try to keep things simple so while we will do our best to explain things, we will work equally as hard to keep those explanations on a very basic level.

Tire Pressure

Just like riding a bike, when the tires on your car are low, it takes more effort to get the car rolling and more effort to keep it rolling.  In other words, your engine will run more while you accelerate which will hurt your mileage.  Likewise, when you let up on the pedal in an attempt to coast, you will not roll as far which will require you to use the accelerator more which will, of course, hurt your  mileage.

Toyota recommends that you maintain a consistent 35f/33b tire pressure (f/b indicates front tires and back tires).  The 2-psi differential between the front and back is to support the weight of the engine.  Some owners have increased their tire pressure to 42f/40b or even 45f/43b.The higher you pump the tires, the stiffer the tire and therefore the harder the ride.  You have to remember that the tire is part of the suspension of the car designed to aid in absorption of bumps.  Because this exceeds the pressure rating for the tire, we can not condone this over-inflation strategy. 

However, in exchange for a bumpier ride, all owners who have over-inflated their tires report an improvement in mileage almost immediately.  They report being able to stealth easier with over-inflated tires and claim to be able to glide farther.  There have been no reported tire blow-outs attributed to over-inflated tires.  Likewise, because new tires are designed and manufactured differently than older tires, over-inflating new tires does not create the center bulge we all learned about and the tires do not wear in the center.  In fact, owners who have over-inflated their tires have reported their tires lasting longer than the manufacturer specifications.  But again, we can not condone this behavior or tell you that it will benefit your mileage. 

Your Prius' Exterior

When Toyota designed the Prius, they did not have a roof rack mounted on it nor did they have any other form of extraneous exterior appendages.  The Prius was designed with one of the lowest coefficients of drag (0.26) of any vehicle currently on the road.  Adding items to the exterior of your Prius will hinder the flow of air and reduce your overall average mileage. Short version: if you don't need it protruding from or bolted to the outside of your Prius, take it off.

John puts his kayak carrier on his Prius only when he's actually using it.

Anticipate Traffic Situations

This one should be a no-brainer but it's amazing how many people simply don't do this.  Someone on a Prius forum started using the phrase, "drive like you have no brakes."  Indeed, if you did not have the option to slam on your brakes when you come to a red light, you most certainly would let off your accelerator considerably sooner and coast to a stop.  Likewise, if you could not suddenly brake, you would not ride so closely behind the car in front of you in tight situations. 

Anticipating Traffic Situations is more than just coasting and maintaining a safe following distance, it's understanding traffic patterns and watching the other vehicles.  For example, even if the red light you are approaching turns green, you can expect about one to two seconds per car before the entire line of stopped cars is moving again; if there's a line of five cars already stopped, you have about ten seconds longer before you can go through.

A funny thing happens when people get off their bicycles and step into vehicles: they forget how to anticipate and coast.  Again, think of your Prius as a bicycle and remember how you ride your bike.  You should coast to stop signs and stop lights.  You should watch the other vehicles to see what they are doing.  And you should drive like you have no brakes.  [Demonstration]

Coast Early and Coast Often

Hopefully you understand that for the first five minutes or so, your engine and catalytic converter will warm up.  You engine is extremely unlikely to shut off during those first five minutes.  This section assumes that you've been driving for enough time to allow for proper engine shut-off.

Of course, the first thing passengers notice when riding in the Prius is that the engine will shut off when the car comes to a stop.  What most of them don't realize is that by the time you come to a stop, the engine had already been off for quite some time.  Unfortunately, it seems that many Prius owners forget about that.

When traveling downhill, approaching congestion or a stoplight, you should apply as little pressure on the accelerator as possible.  If possible, you should work the pedal until the MultiFunction Display shows no arrows.  This means that no gasoline is being consumed and no battery power is being used.  Also, there is no regeneration taking place from the wheels.  In the end, the less you run your engine, the better your mileage will be.

Drive at Reasonable Speeds

We normally take air for granted.  After all, it's everywhere and we don't see it.  So let's compare it to something we can see and feel: water.  If you place your hand on a pool of water and push down slowly, you have no problem submerging your hand.  However, if you've ever smacked your hand on the surface of a pool of water, you understand that the water can't get out of your hand's way fast enough to allow smooth travel.  Air works the exact same way.

Multiple studies have shown that 55 miles per hour is the optimal speed for efficiency.  As you exceed 55 MPG, the air has more and more difficulty flowing around your car.  This means that your car will need to work harder to maintain those speed.  This chart is for the average American sedan, but it works for all vehicles.  It is very easy to see a drop in mileage at speeds greater than 55 miles per hour.

Plan Your Trips Accordingly

The Prius operates at peak efficiency only after the engine and catalytic converter have heated up.  This process takes about five minutes.  For this reason, trips lasting less than ten minutes will damage your mileage.  Trips less than five minutes will absolutely kill it.

For that reason, if you have to run a series of errands on a Saturday or Sunday afternoon, you should plan accordingly.  Go to the destination that is farthest away first.  This way, you can properly warm your engine.  It will cool some while you are there, but it will warm back up as you proceed to the second destination.  You should continue this and end at the destination closest to home.

If you go to the destinations in the order of closest-first, your engine will never have the opportunity to warm.  Therefore, you might never operate at peak efficiency.

Use the Proper Oil

The Prius owner's manual as well as the oil cap itself indicates that you should always and only use oil rated at 5W30, not 10W30.

Don't Drive With Your Foot

Yeah I know it sounds weird, but have you ever caught yourself pressing hard on the gas pedal but it's not really helping you go any faster?  Your goal in the Prius should be to press only as hard as is required to maintain your current speed. 

The next time you have an opportunity, try this: get to a speed that you want to maintain.  Then start letting up on the gas pedal every so slightly while watching the speedometer.  Continue letting up until you see the speed change.  When your speed drops one MPH, glance over at the MFD and see what you're mileage is at that moment.  If you can break the habit of driving with an unnecessarily heavy foot, you will see your mileage improve.

Drive to the Capabilities of the Car

Let's face it, there are some things that the Prius does very well.  The key to achieving good mileage with the Prius is to learn how it works and drive in such a way that you accentuate it's capabilities.  The key with the Prius is to allow it to shut the engine off.  Here are a few tips for those situations when it's best to just let the Prius take over.

Are you maintaining a speed below 40 MPH?  If so, try to stealth.  Within certain parameters, the Prius will maintain the all-electric mode known as Stealth at speeds below 40 MPH. Once you get really good at Stealthing, you will find that you can stealth for very long distances while maintaining the same speed - sometimes speeding up and slowing down as traffic dictates.

Are you going downhill?  Let up on the gas.  Seriously, I can't count the number of people I know who actually accelerate with the gas on a downhill slope.  Regardless of the speed you are traveling, if you are moving downhill, the Prius will shut the engine off.  Just let it do its thing.

Are you accelerating to a red light / stopped traffic / stop sign?  Okay, that's just plain silly.  Coast.  Again, let the Prius shut the engine off.