Page updated July 2024
This is a record of the 2023-2024 fuel mileage of my 2015 NBC110, with over 72,000km on the odometer.
The bike uses an air cooled, fuel injected 109cc OHV 4-stroke engine, with a four-speed manual transmission and centrifugal clutch. Average fuel economy is currently at 1.595l/100km, with fluctuations likely due to occasional motorway trips beyond the usual low speed commute.
Energy Consumption and Thermal Efficiency
During September of 2023 I recorded a series of ten time, distance, and elevation change measurements during my commute. On average the velocity is 30.551km/h over a distance of 11.54km and an elevation change of 159.54m.
Using the volumetric energy density of petrol at 9.51483kWh/l* at an assumed 1.595l/100km, we can then derive the average power consumption of 4.635kW. At an assumed 25% efficiency, only 1.159kW of this will be converted to engine shaft work, of which an estimated 195W, or 17%, goes towards grade climbing for a 170kg gross vehicle mass.
The majority of the 964W of remaining power likely goes towards overcoming air resistance, with some additional transmission, driveline, and tyre losses.
*This is the Lower Heating Value (LHV), which excludes the energy released by condensation of exhaust steam that would add approximately 6.6% to the total specific energy.
