Home cars Real-word mpg and emissions: how efficient and clean is your car really? cars Real-word mpg and emissions: how efficient and clean is your car really? By - May 2, 2024 18 0 FacebookTwitterPinterestWhatsApp In 2018, WLTP and RDE tests measuring car MPG and emissions replaced the older, less accurate NEDC tests used before. The aim was to better reflect the fuel economy owners would get in the real world.