considered ok. open window even if not much cost you more petrol than you on aircond.
the car is more efficient and give you better fc at 110kmh. 6.6l/100km is somehow not always achievable. driving with light foot, maintaining the car well, provided the car is using new parts and fresh oils and also have very little wear and tear, you can achieve it. but that figure can no longer be achieved by me coz the car somehow are considered to have some age and wear and tear. unless you are sure that not a single parts in the car have wear. suggestion is aircond on, spending few bucks for the better air i think is ok. if you did not change the timing belt and aircond pulley belt before and your car now is at 147k km, you better change it. price wise definitely it will not be cheap.

Comparing FC with other is not going to help due to different driving conditions, style, traffic, city vs highway speed ratio, etc.

If you want to ensure your engine is in tip top condition, just change your engine oil every 5K (not 10K) to clean the engine frequently.

Decarbonise the engine, then go clean throttle body. Ensure air filter lasted no more than 20K mileage, change a new filter every 10-15K if possible. Change fresh gear oil every 20K at minimum. Make sure there is no leak in engine. If parts were already worn, go no choice, either live with it or change new ones, a good mechanic can do a thorough check and do recommendation.

Go install Lighten Crank Pulley by Works Engineering or Mytheo if you can afford it, if you want to avoid heavy footing during traffic jams.

An average of 8-9 liter / 100 km for a balanced mixed of highway and city runs. Pure city runs can go anywhere from 9-12 liter /100km. Heavy footer tak payah cakap, 13 liter and up. Pure highway runs can go about 7+ to 8 liters / 100km.

Mine is 143k km mileage.. Its just bullshit to focus on fc when ur car is this old. Ur engine also wear & tear. U can tune ur car hardcore, noo problem at all. Polish ur engine watsoever.. But i cn assure tht after u tune it, ur car feel lighter n ur rite foot becomes gatal to press more harder.
Then final result... Same fc bro..

Max i think 10l/100km.. Beyond tht, u gotta change to vios alrdy. Better to use ur petrol money for paying vios monthly.