This dataset, provided in CSV format, supports the findings of the associated research paper. It contains anonymised vehicle-level data with technical attributes and corresponding real-world emission factors (EFs), calculated to three significant figures. Key variables include vehicle characteristics (e.g., Euro standard, registration year), test conditions (vehicle-specific power, repeats), and both distance-based (g/km) and fuel-based (g/kg fuel) emission factors for NOx, NO₂, NO, CO, and PM.