On a recent trip to Florida I was getting anywhere from 8.2 to 9.0 Liter per 100KM, which is about 31 to 34 Miles per imperial gallon or about 25 to 27 miles per American gallon .No A/C, fully loaded and driver and passenger. Did the speed limit as posted, 60 to 70MPH and at times 55MPH
I would fill the tank get on the highway get up to speed and reset the computer to see my miles per gallon, used cruise all the time. From Orlando to Tampa on I4 speed at 60MPG cruise on no A/C was getting 7.4 L per 100KM or about 35 Miles per Imperial gallon or about 28 miles per American gallon. Must have been going downhill all the way? When I filled up the computer would tell me I would get 795KM per tank at the speed I was doing on my last tank full.
Never bothered to check by hand to see if the computer is correct but I do daily check when home and the computer is pretty close to my hand-paper calculations.
I have a 2010 FWD Edge SEL... 23,000KM or 14,300 miles