Sharing fuel consumption from my recent experience over approx 600km
20km/l around town in ISB, with econ button on, climate control at 25C, relaxed driving, usually 2 sometimes 3 persons on board. Standard steel wheels with original dunlop 175/65R15 tyres at 30psi all round.
The onboard computer suggested 20.1kmpl, and fuel top-up to fuel top-up came as 19.98kmpl. So essentially same!
The car speedometer and odometer comparison was also done. The speedometer shows a difference of 2kmph, i.e. 100kmph on car speedo equated to 98kmph on Garmin GPS. Also distance covered of 50km on GPS showed as 49.8km on car odometer!