Coach fuel consumption

Thanks to an extensive database Volvo Bus can present detailed fuel consumption data from real use on a yearly average. In the example below my colleague Anders Tuomivaara has aggregated data for Sweden, Finland, Denmark, Germany, Poland, Netherlands, Belgium, UK, at real world conditions far from the laboratory.

In 2006 Volvo Bus and the DH12 (in B12B and B12M buses) engines secured a leading position in fuel consumption in real use on a yearly basis. The breakthrough came with a new engine generation in combination with a new gearbox, the now a days legendary I-Shift. The fuel consumption was determined to in average 26 liter per 100 km (for the average speed of 60 km/h), including all idle and auxiliaries such as air conditioners and winter heaters.
When Volvo Bus introduced the 13 liter engine in 2010 the forecast said an expected average fuel consumption decrease by 4-5% depending on the average speed. We have now gathered enough data to confirm that the average saving is 4-6% in real operation.

Several factors have high impact on the fuel consumption. In the data below we have grouped the coaches in three groups. Coaches with a yearly average speed of 35-45 km/h are represented by the speed 40 km/h. The group with speeds between 45 and 55 are plotted as 50 km/h and so on. Note that at constant speed the fuel consumption increase with higher speed, this mostly not the case in real operation of buses.

volvo 9700 yearly average fuel consumption

Graph: Fuel consumption for a 9700 12 meter with 4×2 axle configuration one example automatic gear box is compared to the I-Shift gear box plotted for average speed of 40, 50 and 60 km/h.

 

Last year, 2012, Volvo Buses presented another new engine range for coaches based on the D11 engine. Although we have not yet a full year of data we have an indication that we are heading in the right direction. Even if the decimals are not in place we have now enough information to state that the superior fuel consumption of the new product line is confirmed, again.

 volvo 9700 yearly average fuel consumption

Graph: Fuel consumption for a 9700 13.5 to 14.5 meter with 6×2 axle configuration with the I-Shift gear box plotted for average speed of 40, 50 and 60 km/h.

 

We are immensely proud of our new engine technology that has been realized by our engine development colleagues at Lundby and Lyon.  And, it will continue to progress already by the end of the year, when introducing the Euro VI engines. One of the secrets behind the progress for the larger 6×2 coaches is that the new D11 engine has the same power output as we have for the larger D13 engine.

And, I am immensely proud of our contribution to the lower emissions of greenhouse gases. Coaches in general have a filling factor of about 60%. On some markets it is higher and on other markets it is a bit lower.

 

Carbon dioxide emissions per passenger kilometer (g CO2/km) for Volvo 9700 4×2 12 meter, with the new D11 engine range.

  Average Speed km/h

PAX

40

50

60

30

24

22

21

40

19

17

16

Carbon dioxide emissions per passenger kilometer (g CO2/km) for Volvo 9700 6×2 14.5 meter, with the new D11 engine range.

  Average Speed km/h

PAX

40

50

60

40

20

18

18

50

16

15

14

60

15

13

12

Note that the data above are average European numbers, higher values are expected in the Alps and lower values are expected in the flat countries.

About volvobuses

Adjunct Professor of Catalysis at Chalmers University of Technology. Lives in Gothenburg, Sweden, with my wife and three daughters born in 1991, 1994 and 1997. Is a passionate runner with a half marathon personal best of 1.24.
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2 Responses to Coach fuel consumption

  1. Paul Rodrigues says:

    Extremely interesting data. Can Volvo ”crunch” similar data for the Volvo 7900 Hybrid series in the near future?

  2. volvobuses says:

    Yes, let me come back within shortly with a detailed report

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