14bhybrid driving, 15bbrakes, Hybrid driving – TOYOTA Prius HSD User Manual
Page 5: Brakes
Hybrid Driving
From a Stop
The gasoline engine is most efficient when running around 70% maximum. So if you can't press
lightly enough on the pedal to accelerate using only electricity, go ahead and press a little harder
than usual. That brisk (but not aggressive) increase in speed will save a small amount of gas,
resulting in an overall efficiency gain.
Climbing Hills
The hybrid system has two electric motors. When you encounter a large hill, those motors are
automatically taken advantage of. The gasoline engine will rev to its most efficient high-power
RPM. That provides thrust directly to the tires, generates electricity for the motor, and recharges
the battery-pack all at the same time. So to the surprise of many new owners, large hills don’t drain
the system. You’ll still have plenty of reserve power available when you reach the top.
On the Highway
Just like with traditional vehicles, efficiency drops the faster you drive on the highway. 60 MPH
(96 km/h) is more efficient than 70 MPH (113 km/h). Speeding up to 75 MPH (121 km/h), you'll
observe MPG drop even more. It is beneficial to drive slower.
Without the Pack
The large electric motor doesn't actually need electricity from the battery-pack. The gasoline
engine generates electricity while you drive for immediate use. So quite frequently, you’ll see on
the multi-display that the motor is being fed directly from the engine and the battery-pack isn't
being used. Sometimes, while both the engine and motor are providing thrust, the engine will also
recharge the battery-pack at the same time.
A/C Instead
At highway speeds, using the A/C (air-conditioner, cold setting) or vent to remain cool will likely
result in slightly higher MPG than having the windows open.
Cruising
A beneficial technique for efficient cruising is to feather the accelerator pedal at particular times.
Learning to do this is simple and will quickly become second nature with very little practice. (In
fact, you may already have that foot control if you in-line skate or bicycle occasionally.) To do it,
just lightly reduce pressure on the accelerator-pedal whenever you encounter a section of road
that’s perfectly flat or has a slight decline. The MPG indicator will sometimes jump all the way to
the +100 mark, even though your speed ends up dropping only 1 MPH. Then lightly push the
accelerator-pedal to efficiently regain that speed afterward. Overall, MPG will climb a little bit
when each time you do that.
You’ll end up taking advantage of the hybrid design. Changes in the road pitch naturally cause
changes in speed anyway. Using the multi-display and large digital speedometer helps you
discover when gains from that are possible.
Brakes
Regenerator
When you reduce pressure on the accelerator-pedal or use the brake-pedal, excess speed turns a
motor, causing regeneration of electricity to recharge the battery-pack. The regenerator takes
advantage of the kinetic energy that would have otherwise been lost. The brake pads & shoes are
not used as much as in a traditional vehicle. This not only makes the Prius more efficient, it also
indicates the brakes will last longer.
Prius User-Guide
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Last Updated: 9/01/2007