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Advanced Prius Mileage Tips
How do some Prius drivers achieve fuel economy above the EPA mileage estimates — while others barely reach 40 mpg? What techniques allow some
drivers to consistently break 70 mpg?
This is our attempt to organize some of the best Prius mileage tips we
have found on the web. Ultimately, it's your job to see which of these techniques produce the
best results for you.
The following advanced mileage tips are not officially endorsed by Kent Brown
Toyota or Toyota Motor Sales. They are presented as suggestions only, and
should only be used in appropriate driving conditions.
Please remember to always drive safely!
OVERVIEW
Toyota's sophisticated hybrid system allows nearly all drivers to achieve
better than 40 mpg. Master the art of
"Gliding" and your mileage could
surpass the EPA's combined mpg estimate.
Break-in Period
- Give any hybrid a full six months and/or 10,000 miles to get broken
in. The biggest impact occurs in the first 2,000 miles or so, and it may
take as much as 15,000 to achieve peak mpg's. Hybrid owners commonly
experience a 10-15% improvement in fuel economy after the new car smell
has drifted away.
Route Selection
- Speed is your enemy. The ideal routes have long stretches without
stops, and speed limits of 30 – 35 mph. (The sweet spot for most
hybrids, in "steady state" testing, is between 40 and 45 mph.)
- Don't be concerned about hills, especially routes with short steep
uphills and long gradual downhills. The glide or coast on the way
down—especially if it's uninterrupted—will more than make up for the
extra energy to get to the top. And the downhill stretches will give you
a chance to recharge your battery through regenerative braking.
- Pick routes that are less windy. A hybrid's aerodynamics are
streamlined for head-on gusts, but swirling and sideways winds can
destroy high mpg. Tail winds are great.
- Experiment with multiple routes to see which paths consistently
produce the best mileage.
When to Drive
- Cold starts are mileage killers. The Prius and other hybrids get the
worst mileage in the first five to ten minutes of driving.
- Try to get all your errands done in one outing. If you can help it,
drive after the day has warmed up. Hot humid air is the least dense, and
produces the least air resistance.
- Avoid rush-hour traffic, if at all possible.
- Driving during rainy, slushy or snowy
conditions will decrease your mileage.
Tire Pressure
-
Tire pressure (i.e., rolling resistance)
has a significant influence on fuel economy, and an obvious impact on
safety and the quality of your ride. Do the research, and make your own
decisions about how far to take the tire pressure to maximize mileage.
- Maintain the maximum recommended tire pressure. Check the tire
pressure regularly so the pressure does not fall below the maximum
level.
Fuels
- Low octane gasoline is best. (There is actually less energy in
high-octane fuel.)
- Some convenience stores may use more additives than "name brand" gas
stations.
Distance from Other Vehicles
- Be aware of road conditions. The most important factor in maximizing
your mpg is your ability to take your foot off the accelerator
absolutely as soon as know that you'll need to slow down or stop—and
getting into "glide" mode .
- To give yourself time to stop and coast, create space between you
and the car in front of you—except when you have the opportunity to
"draft" behind larger vehicles on the highway. You can obtain the
mileage benefits of drafting while maintaining a safe distance of 150 feet of
more.
Starting & Warming Up
- Frequent short city trips will not produce good mileage, even though
the Prius is rated very high for city driving. Combine errands to reduce
the number of warm-ups.
Dashboard Displays
There are two schools of thought about using the Prius's display
to maximum effect.
- Simple: Watch the instantaneous mileage numbers.
Learn what produces the best results by watching the effects of your
experimentations. Don't worry about the arrows that appear on the
"Energy" display.
- Advanced: Use the Energy display to watch the
direction of the arrows. Drivers getting the best mileage are able to
use split-hair changes in how they press on the accelerator and brakes
to move energy from the gasoline engine to the wheels and/or the
batteries—or to get all arrows to disappear completely from the screen,
in what is referred to as "glide mode." (More on this below.)
Learning how to get the system into these different states is only
possible if you monitor the Energy display and keep an eye on the
results of your fancy footwork.
Accelerating & Cruising
- Never mash your foot to the floor. Accelerate slowly especially from
a standstill. (Some Prius drivers prefer moderate acceleration before
gliding with the engine off.)
- If you would like to simultaneously send energy to the wheels and to
the hybrid batteries—for example, when you have the headlights on at
night and you have a low charge, follow these steps:
- While traveling above 20 mph, slightly lift your foot off the
accelerator (but not all the way).
- Reapply your foot gently, until the Energy display shows the
energy flow going to the wheels and the batteries. If you push the
accelerator too soft, all arrows will disappear (and you will be
gliding). If apply too much pressure to the accelerator, all of the
gasoline will go to the wheels.
- When you need to enter a highway or otherwise rapidly accelerate,
simply stomp on the gas and go. The battery power will "assist" the
gasoline engine, thereby reducing your fuel use as much as possible.
- For highway driving, get best results by setting cruise control at
55 mph. For every mph over 50 mph, you lose approximately 1 mpg.
Slowing down from 65 to 60 mph or from 75 to 70 mph will save you
approximately 5 mpg.
Braking & Deceleration
In the eyes of advanced Prius drivers, the way you slow down and
brake is much more important than acceleration techniques—and the
goal is to "glide" (description below) at every opportunity,
regardless of the traffic conditions.
The main idea is to control the amount of braking that is used to
regenerate energy to the batteries. (Regenerative braking is essential for
keeping energy in the batteries, but a little bit goes a long way.
Avoiding overuse of regenerative braking will prevent you from slowing
down more quickly than necessary. Extending your glides and coasts is a
key to maximizing mileage.)
- Gliding (least aggressive) – While traveling, remove foot
from accelerator. Then, ever so slightly, re-apply pressure until all
arrows disappear from the Energy screen. You'll a feel slight surge
forward.
This technique will only work when the car is warmed up.
You can glide at any speed, but it's difficult to get the arrows to
disappear at speeds higher than 40 mph. At the higher speeds, even if you
are gliding, the internal combustion engine will spin in order to protect
the smaller electric motor from getting damaged. Above 40 mph, the engine
is spinning but no gas is being used. Under 40 mph, the gas engine is not
spinning. (Some Prius drivers report a "sweet spot" at 39 mph.)
- Coasting (slightly more aggressive) – This kind of
braking is much easier to explain. Simply remove your foot entirely from
the accelerator, but do not apply it to the brake. Regenerative braking is
engaged, so you will slow down more quickly than gliding.
- Regenerative Braking (aggressive) – Press down on the
brakes, but not firmly. As you press, you'll obtain more regeneration than
with coasting, and the electric motors (now acting as generators) will
make you slow down quickly.
- Mechanical Braking (most aggressive) – Firmly stomp on
the brakes to immediately stop. You will obviously use this style of
braking if a vehicle or pedestrian jumps in front of you.
Use the least
aggressive method to travel as far as possible before needing to
accelerate again.
To recap, the most important point: Anticipate the need to stop so you can
slow down in a glide or in the least aggressive manner. If you do nothing
else but get your foot off the accelerator more quickly, you will increase
your mpg.
Another "magic number" is 7mph. Below 7 mph, regenerative
braking stops and friction
brakes are engaged—wasting energy that could be stored in the battery. Try
to avoid slowing below 7 mph by decelerating earlier while approaching a
red light, so that it turns green before you get there.
All-Electric Mode
Advanced high mileage Prius drivers do not favor all-electric mode as the optimum strategy
for maximizing mileage. They prefer to alternate between the gentlest use
of gasoline (pulse) and the gliding technique described above. See
Advanced Techniques below for a detailed description of the pulse and
glide technique.
In certain situations, such as the last mile or so of your trip, the
all-electric mode is more advisable. (The batteries will recharge quickly
on your next start-up.)
How do you get into all-electric mode?
- While traveling, remove foot from accelerator and
then, very gently, re-apply pressure to the accelerator.
- Ever so slightly increase the touch on the
accelerator (hardly moving your foot at all) until arrows on the Energy
screen flow only to the battery.
Maintain steady speed to remain in all-electric mode.
A sustained period of all-electric driving will deplete the battery
charge, which could trigger the use of gasoline to recharge the batteries.
Idle versus Shutdown
If you need to remain stationary for no more than ten minutes or
so—stopping to run quickly into your house or pick somebody up—place the
Prius into park, but don't shut down.
Turn off the heating, cooling, lights, and other electric accessories.
Push the "Park" button.
The goal is to avoid shutting down and restarting, at which time the Prius
will run through a startup cycle that uses gas.
Gear Selection
There are not a lot of gear selections to consider. (Think of
your foot as the main control for maximizing mileage.) The one exception
is the B gear.
The B gear should be used only if you are going down a long hill. The B
gear lets the engine slow down the car without overusing your brakes and
over-charging the batteries.
AC and Accessories
It's best to avoid AC and Defrost whenever possible when trying to achieve
maximum mileage. Using the
vent function with the temperature set to your preferred comfort level
works well on long trips.
On hot days, set the AC two degrees lower than the outside temperature or
to 85, whichever is lower. This setting keeps air coming into the Prius
using the least amount of energy.
Avoid using the MAX setting.
State of Charge (SOC)
Two or three bars from the top is fine. When you are missing five
bars, the gas engine will kick in to recharge the battery.
When you are three bars down, consider the technique of sending gas power
to wheels and battery (watching arrows and wiggle foot to get it) or use a
slightly more aggressive form of braking to increase the amount of
regeneration.
It's okay to allow the charge to drain at the end of the drive, or
right before an anticipated long downhill stretch.
If the SOC gets too low, you can't get into glide mode.
Cruise Control
Cruise control, which provides smooth acceleration and allows the
computer to make the fuel-saving decisions for you, is recommended in most
situations. It works well on flat driving, and is excellent for
non-congested highway driving.
Set at 55. (Good way to discipline yourself to keep your speed down.)
Lower speeds will produce even better results.
Cruise control is not nearly as good in hilly terrain, where uphills
produce aggressive driving and too much regen braking on downhills. When
you're going downhill in cruise control, you can give a little push on the
accelerator, which will disengage regen and give you even more speed.
Maintain safety by not allowing to much speed to build up.
Advanced Techniques
The Pulse and Glide technique, which has allowed some drivers to achieve
exceptional mileage, is ideal for roads that allow 30 – 40 mph
unobstructed driving. Pulse and Glide will be more difficult in any road
conditions with busy traffic or numerous traffic signals.
- Accelerate moderately (not babying accelerator, but
not gunning it) to 40 mph.
- Then ease off the accelerator. Then, ever so
slightly press down on the accelerator again and hold the pedal in that
position.
- Glide (engine on but not turning over and
transmission in neutral). At this point, the energy screen should not
have arrows going in any direction. This state has been referred to as
"dead band." If you press too much, repeat the process of easing up and
pressing down again until you find the right spot. At this point, you
are coasting without any energy being used to charge the battery.
- Coast down to 30 mph.
- Gently accelerate (pulse) back to 40 mph.
- Repeat steps, alternating between gentle
accelerations to 40 mph and gliding down to 30 mph.
CONCLUSION
Conventional driving techniques will not give you the maximum mileage your
hybrid vehicle is capable of achieving. If you modify your driving habits
using one or more of the advanced driving tips above,
let us know
what tips worked best for you!!!
The above mileage tips were found from several sources by doing a web
search for 'Prius mileage tips'. We may update or modify these tips at our
discretion. Please feel free to
contact us with your own service tips for
possible inclusion!
The above advanced mileage tips are not officially endorsed by Kent Brown
Toyota or Toyota Motor Sales. They are presented as suggestions only, and
should only be used in appropriate driving conditions.
Please remember to always drive safely!
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