TOYOTA Prius HSD - Manual (Page 6)

Stealth Driving
Engine Off While the gasoline engine is off and you’re driving using just battery power, the mode you’re in is
called "stealth" (since the vehicle motion is totally silent).
Invoking "stealth" is easy once the engine has warmed up (and you aren't running the A/C or Heater
too heavily). While driving, just find a street section without any inclines then lift your foot from
the accelerator-pedal. The engine will shut off within a few moments. Once it does, lightly place
your foot back on the accelerator-pedal to continue driving with only electricity. Another way to
invoke stealth is to just stop completely, that will make the engine shut off.
Up to 42 MPH The 50 kW electric motor is designed to propel the Prius up to 42 MPH (68 km/h). It takes a steady
foot though. Slower speeds, like 35 MPH (56 km/h) and 30 MPH (48 km/h), are easier. Beyond
that maximum speed or in conditions when additional power is needed, the electric motor works in
combination with the gasoline engine. Though, you will discover above 42 MPH (68 km/h) that
there are times when the engine will spin (pistons in motion) without any fuel being consumed; it is
a normal function of the Planetary-CVT.
Acceleration Accelerating in "stealth" can be very slow. Also using the gasoline engine is both quicker and more
efficient, so don't be afraid to consume a little bit of gas. Remember that even if you use the battery
and get "+100 MPG", the engine must run later to recharge it. So short-term gains may actually
result in an overall loss.
A/C & Heater Only the lowest setting for the air-conditioner & heater work in "stealth". Higher settings and
airflow durations longer than a minute or two will require the gasoline engine to run.
Be Careful ! Be careful while driving in "stealth", especially in parking lots. Some people use only their ears to
verify that it's safe, not their eyes! So having a car that's completely silent means you'll probably
have someone step out in front of it without even realizing you’re driving right at him or her. And
fortunately, the quiet actually makes it easier to hear children (who commonly don’t look anyway).
"B" Mode
On/Off Anytime You can engage or disengage engine-braking at anytime while driving.
Engine-Braking Avoid using this mode unless absolutely necessary, since it will cause MPG to drop. There is no
charging benefit over regular (foot pedal) braking either.
"B" mode works like an exhaust brake on a large truck (except, it's totally silent). The engine is
used to slow down the vehicle, allowing you to reduce reliance on the regular brakes. So for steep
declines, like driving down a mountain, it's a great way to avoid overheating caused by friction
from the brake drums & shoes.
Winter Slowing A special use of "B" is the ability to shift into it on-the-fly without having to take your eyes off the
road. Finding yourself taking a turn on snow or ice a little bit too fast, you'll discover "B" does an
absolutely fantastic job of slowing the car enough to retain traction without any risk whatsoever of
the wheels slipping from braking too hard... since you aren't using the brakes at all.
Prius User-Guide 6 of 54 Last Updated: 9/01/2007