(Information on fuel consumption and CO2 emissions as well as efficiency classes in ranges depending on the tires and alloy wheel rims used)
Audi RS 6 Avant
Combined fuel consumption in l/100 km: 11.7–11.5 (20.1–20.5 US mpg); Combined CO2 emissions in g/km: 268–263* (431.3–423.3 g/mi))
Audi A6 Avant
Combined fuel consumption in l/100 km: 7.–4.1 (31.8–57.4 US mpg); Combined CO2 emissions in g/km: 169–108 (272.0–173.8 g/mi))