| |
5 - RPM range:
In order to use the engine characteristics in the most
efficient way, the highest torque range of the engine
should be used while driving. Graphs called "Torque
graph" show the engine's torque at different rpm.
Engines running on gas (petrol), at least the
atmospherically aspirated ones, provide their maximum
torque at higher rpm, usually, around 3500-4000 rpm.
This rpm range is good for starting acceleration (for
overtaking), however, the most economical rpm range for
cruising is around 2500 rpm, depending on the engine and
load conditions. In petrol engines with a turbo (or a
supercharger), just like the diesel engines (which all
have turbos) the maximum torque is usually provided
between 1600 to 2300 rpm. So, they run at higher
efficiency at lower rpm and should be driven at these
rpm both for performance and fuel economy. |
6- In the city:
This is where the fuel consumption is highest because of
many stops and crowded traffic. Leaving a bigger gap
with the vehicle at the front and watching the traffic
ahead would allow you to take your foot off the
accelerator earlier and save some fuel. Every time you
brake, the fuel you used to accelerate the car is
wasted. Therefore, having a very light right foot is
important. Taking your foot off the accelerator when you
see the red traffic lights and using the engine braking
whenever possible would also save fuel. Some traffic
lights may have counters showing how many seconds later
the lights would turn green. If it is 25 seconds or
more, engine could be turned off and restarted when
there are 3-4 seconds to go. |
7 - Outside the city:
When the road is empty, selecting the highest gear and
going at a low rpm would save fuel. As the speed
increases, so are the mechanical losses and air drag
which would increase the fuel consumption. For example,
in some cars, fuel consumption at 130 mph is almost
double the consumption at 50 mph. On the highway, you
can save 15-20 % fuel by going at 70 mph instead of 80
mph. If it is a 30 mile journey, you would reach your
destination only 4 minutes later. Trying to keep a
constant speed would also save fuel. Continuously
pressing the accelerator pedal and then letting it off
would waste fuel. Planning the overtaking maneuvers
beforehand and gaining speed before starting the
overtaking would be better both for the fuel consumption
and safety. |
|
|
|
|
|
8 -
The trip computer:
The trip computer shows the fuel consumption at any
given time. With the help of the trip computer, it is
possible to adjust the engine speed and the gear
selection for the lowest consumption. Trip computers are
very helpful devices in helping save fuel. By monitoring
the trip computer it is possible to have an idea on fuel
consumption in certain situations and after a while it
becomes a habit to drive economically. |
|
9 -
The cruise control:
Using the cruise control in motorways
would help saving fuel by keeping the speed constant and
would also allow the driver's right foot to relax. If
the cruise control is set to an optimum speed for the
fuel consumption and the road conditions, in minimizes
the fluctuations in the speed of vehicle and lowers fuel
consumption |
|
Go to page 1 |
|
|
|
