2F/2F I don't understand your insistence about a fuel consumption figure. They can vary wildly. Half a world says "your mileage may vary" because it does vary a lot.
When I drive Joséphine*, a small motorbike, in a "sporty" way in the countryside, and I'm no speed fanatic at all, fuel consumption doubles.
When I am stuck with my car in Roman traffic jams I have no idea how much I consume, but it's not comparable, not even from far, from normal average.
Galileo Galilei taught us that a body which has reached a certain speed, if no force intervenes in stopping its motion, goes on and on forever. So when a car advances in flat road, after you put it into speed, you are expending energy only to win frictions and air resistance.
But any time you stop and start again, you have to spend a lot of energy to put the mass in motion again and again, that's where you spend energy, not in maintaining the car in motion.
So if you practice rush hours every day, your fuel consumption can skyrocket because you have to constantly put the car mass in motion. If you drive in a low-density traffic, you only have to maintain the car in motion.
Figures about fuel consumption are only indicative to compare different cars in the same traffic conditions. They have no absolute value whatsoever. I do more than 16 km/l in normal traffic, and probably less than 5 km/l in a bumper to bumper situation. (Never measured actually).
* The world knows the model as Suzuki GSF 400 "Bandit", 1992.