This is the data set associated with the journal article titled 'Effects of Semi-trailer Modifications on HGV Fuel Consumption'. The data files are in MATLAB file format.

Figure 4 was generated using the vehicle speed profile during a coast-down test conducted at MIRA-HORIBA twin-straight test track at Nuneaton, UK.

Figures 5(a) and 5(b) were generated using vehicle speed and acceleration data from a coast-down test. Figure 5(b) was plotted after compensating for the wind speed.

Figure 6 was generated using the time and vehicle speed data from a cost-down test. The modelled legend shows the simulated vehicle speed profile with the estimated vehicle parameters, i.e. the estimated coefficients of aerodynamic drag and rolling resistance.

Figures 8(a), 8(b), 8(c) and 8(d) were generated using a simulation model with different combinations of the estimated vehicle parameters as mentioned in the legends. They show the fuel consumption benefit as a percentage.

Figures 9(a) and 9(b) were generated using a simulation model with different combinations of the estimated vehicle parameters as mentioned in the legends, and they show the absolute fuel economy.

All the files were generated using MATLAB software package from Mathworks.