its a myth that fuel consumption efficiency will get better after 5000 or 10,000 kms... it will not.. tried and tested in my city
its giving me 12.5 - 13.5kmpl in winters (without AC) and between 10.5-11kmpl in summers (with AC at all times) since day 1
and these figures are not what the odo shows .. these are practically calculated by me...reading on the odo is ALWAYS OVERSTATED by around 10-15%... if u put in 20 liters of petrol when tank is empty , it shows a range of around 300km (where it is 0 before refill ), but actually it does around 220-240km
now i dont know if there's a problem in fuel tank or not , but when i took mine out of the showroom , petrol was completely empty . i had put petrol worth Rs1000 and the fuel hand barely moved.. its reserve got filled which is not recognised by the odo... the factory fills it with mere 3 liters...
and as per your odo showing a ridiculous 6.5kmpl , i think u r reving up the engine too high , or that its due to PT , or that the engine was turned on for quite a lot of time without covering any distance.. have u tried resetting the trip and get a new average?
keep rpm below 3000 to get a better economy