Class-8 Heavy Truck Duty Cycle Project Final Report - Center for ...

consumption per unit of distance traveled14 is shown by a continuous line, while the curve obtained
from information gathered from the databus with a sensor that overestimates fuel consumption, is
shown by the dashed line. For example, at distance D1, the real fuel consumption per unit of distance
traveled is FCR1A, while the databus would have indicated FCR1B at the same point where
FCR 1B
FCR 1A
D 1
FCR A
Fuel Consumption per
Unit of Distance Traveled
1 B = FCR1
× p Eq. (1)
FCb
FCa
D 2 D 3 Distance Traveled
Fig. 63. Fuel Consumption for Truck T
In the same figure, the total fuel consumed between points D2 and D3 is computed by calculating the
area under the fuel consumption per unit of distance traveled curved. In this example, the actual fuel
consumed when truck T traveled between these two points was FCa while the databus would have
reported FCb, where:
as can be determined using Eq. (1).
FCb = FCa × p Eq. (2)
Assuming that the distance traveled between D2 and D3 is one unit, then the real fuel efficiency (fea)
for truck T in trip t23 would be:
14 The databus information is provided in terms of fuel rate per unit of time; this information can be combined with the vehicle speed to
obtain fuel consumption per unit of distance traveled.
76