Note: I have no association with either web site as I've taken a
This is a good start but you'll learn a lot more if you can get a
ScanGauge II to instrument the car. Be sure and get the one that is
XGAUGE programmable since these can also provide diagnostic codes. But
three built-in gauges will give three pieces of information needed to
engine coolant - the Prius is very engine temperature dependent and
the simple rule is below 70C, it is an ordinary car and above 70C it
become very efficient. So try to minimize higher power demands until
the coolant reaches 70C.
engine rpm - the engine efficiency of your model NHW20 is somewhat
sensitive to rpm with anything under 2,200-2,600 being very efficient
and above that less so. Under higher power settins, 3,200 rpm and
above, the car is less efficient.
gallons per hour - unlike any other gauge, this gives a direct
readout of the rate of fuel consumption. Acceleration can still be
good with fuel consumption rates under two gallons per hour. But the
car really shines when fuel consumption is in the 0.60-0.70 range or
When the engine is warming up to 70C, I maximize used of "N" so the
engine will turn over at the minimum fuel consumption rate. But once
it reaches 70C, I only use "N" if I need to coast a longer distance.
Otherwise, I just used cruise control and pay attention to traffic.
My web page shows my approach to the problem:
I don't know what rate you used to accelerate at but I can tell you
that you don't have to accelerate all that slow to get good mileage.
Accelerating slowly lowers the rate of output, but it must be
maintained for a longer time to get up to speed. Slowing
gradually,coasting down, makes far more difference. You don't want to
waste the kinetic energy by turning it to heat in the brakes. And
while regenerative braking recovers some energy, it to wastes a fair
amount as heat.
Depends on you plan :) In the "pulse and glide" technique you don't
want to charge the battery, idea being that you never get as much back
as you put in. An alternate method I use is to let off the gas to
shut the engine down, then gently step on the pedal to maintain 35 mph
with the electric motor. When the battery runs down the engine will
start and recharge it. The idea here is that the engine uses gasoline
just to idle. When running on electric alone you save not only the
gas that would be moving the car but the gas wasted idling as well.
When the engine starts you have to replace the energy that was used to
keep the car rolling, but not the energy that would have kept the
engine idling. It ends up giving better mpg than puttering along with
the engine running all the time, but not quite as good as pulse and
glide. On the plus side you maintain a near constant speed.
1. The most important aspect of high fuel efficiency driving is to
give yourself enough time to drive to where you are going.
2. Hybrid usually donot achieve their rated EPA fuel efficiencies
until after they are driven over 15 minutes at summertime
or over 30 minutes in the wintertime temperatures - this is
there is a warmup penality to start up the engine and warm up
the exhaust emisssions system. Whenever possible combine
your driving trips so that that most of your trips are longer
than 30 minutes or 7 miles - this will automatically increase your
During the winter time, you can shorten this warmup penality
for nonhighway/urban/suburban stop-n-go driving trips if the
Prius intake grills are blocked and/or if you install a engine
blockheater. During the winter, if the coolant temperature drops
too low because the gasoline engine was automatically turned
off ( because the Prius is at a stop light or because you
are gliding for a long time) the Prius engine will go on
automatically to warmup the coolant (which keeps the
exhaust emission system at the proper operational temperatures).
You want to avoid having the Prius engine automatically
cycling on to warm up the coolant because it will cause
your MPGs to drop like a rock. So you need to watch the
temperature of the coolant when doing stop and go
driving in colder temperatures - unfortunately the Prius
doesnot have a temperature gauge so you need a ScangaugeII
or something like it to check if the coolant is getting cold.
Before the coolant gets too cold, I will pulse/run the gasoline
engine more frequently just to to keep the coolant from
getting too cold in the winter time.
3. Daniel who wants to know is right to focus on the tire pressure
- the Prius fuel efficiency very sensitive to tire pressure. This
because the tire's rolling resistance decreases with higher
The Prius will coast/glide longer on momentum without additional
energy if it has a lower rolling resistance. Lower rolling
depends on how smooth the road is and the tire rolling resistance.
You can buy Low Rolling Resistant (LRR) Tires or you can
overinflate a tire near its maximum sidewall pressure setting
to lower its rolling resistance. In addition, as the tread of a
wears off its rolling resistance decreases (but its stopping power
decreases as well). Overinflating the tires decreases the rolling
resistance by making the tire more ridge - which can make for
a harsher ride and a tire pressures over the maximum sidewall
pressure can reduce the traction/gripping power of the tire. When
the road surface is rough - an overinflated tire will not absorb
irregularities but *bounce* and rolling resistance maybe worst
than if the tire was as a lesser pressure which would absorb
road surface irregularities and not *bounce.* If the road surface
is rough or grooved due to construction then you'll be better
off with the tire pressure setting listed on the inside
of the driver's door panel (manufacturer's suggested tire psi
The advantage of the LRR is that they should do well regardless
of the road surface condition at their recommended tire pressure
setting. Driving on a smooth well kept road helps fuel efficiency.
4. Avoid using more than 1/2 the high voltage(HV) battery power .
When the HV voltage battery is nearly depleted the Prius gasoline
engine will automatically go on to recharge the HV battery to push
the power level back up to a safe level -- this in turn will push
down because that's the least fuel efficient way to charge the
Prius HV battery. Essentially this drives back to what
Daniel who wants to know asserted - don't depend on the electric
motors to drive the Prius to increase the MPGs - instead focus
on efficiently using the vehicle's kinetic energy-momentum.
when there are no arrows on the Energy Monitor Display - then no
gas or electricity is being expended and the Prius is moving
on its own momentum ( any object in motion will stay in that
particular motion unless acted by another force).
5. The Prius gets the best fuel efficiency if its running between
to 35 mph nonstop for over 60 minutes - however this is not
in the real world most of the time. When on the superhighway if
keep your speed between 50 mph to 60 mph - you'll normally see
much better MPG results than if your speed is beteen 60 mph
to 70 mph. If you are driving above 50mph keep the windows
rolled up - use the AC or the heater if you have too.
6. Cleanmpg.com is for hypermiling
its the best place to get detailed instructions on how to
Priuschat.com is for Prius devotees and those who want to pimp
Youtube.com has some very good video on how to drive a Prius
7. I've read it is possible to use Neutral in a glide to decrease
and extend a glide phase- its an advance P&G technique. On
F8L was asking that very same thing under "extreme hypermiling"
the problem is not that your momentum/kinetic energy will
go to zero but that it the road section ahead has a much higher
cost per mph than the current road section you are on. Each road
is like a store where you can buy mph for X amount of energy.
stores are overpriced and other stores are cheap. So the best
to "Buy low, sell high." Simply put - the most energy efficient
route is to
create speed when the energy cost to create speed is low then
loose speed when the energy cost to create speed is high.
2010 Toyota Prius III, Blue Ribbon/Dark Grey, oem floormats
Yokohama Avid S22 (50/48 psi)
ScanguageII (AVG, MPG/FwT. SoC, GPH)
odeometer +14800 miles, +59mpg overall, 10% Ethanol blend 87 oct