All depends on the way you drive, & traffic.he might drive agrresively in heavy traffic.
When i drive trough maharagama aggressively it does 12
when i drive trough maharagama calmly it does 14.5
I cant believe his figures. because even in heavy traffic my one does 11.
My car has 1KR FE 1000CC engine with CVT gear box.
When i drive to the office in the morning. average speed 25kmph.(i took 45 minitues per 18km).My car does 17 average fuel.
When i return my average speed is 18(i took 1 hour to go back).My car does 14 average fuel.
(17+14)/2It should be more than 15.
but,
On & off there are heavy traffics are met. Some times i have to stop with engine on.Fuel consumption go down when i go to shop in athurugiriya & near town with home town roads. Considering all it gives overall average more than 14.
All day it shows
14.4
14.3
14.8
14.2
Like this.
Then i practically measure it. meter reading & practically measurement has a error of 0.6. I mean when it gives 13.7. I does actually 13. That is the way all meters are working
I'll tell you, When i purchased car ,i go to Borella in the early morning before 5.30am.roads were clear.I drove very fast.becoz i had to admit my child in lady ridgeway. I thought my car would have done more than 18.
But, when i saw the dashboard what i saw was avg.=12.
then i realized that this highly depends on the way you drive.
That's how vitz performance on fuel is 
I
my car