This will improve.
But I am not sure why the huge difference in highway, with and without AC.
May be different highway and traffic conditions? Or load or different driving style. [thinking]
Calculated the mileage by me only on the state highway during the trip to Cuddalore from Vellore & Myself only drove for the entire trip with Mom & Dad, So no load difference in car.
Always calculate FE, full tank to full tank. Don't go by MID.
BTW, In Vista there are no MID, I calculated with Tank to Tank only.
Here is the story:
Started from Vellore at 4:30am on 7th June & Filled the tank in Vellore. due to early morning less traffic I maintained 100+ km/hr. when I reached 100.4Km from Vellore I found a Bunk near Veraiur(Between Thiruvanamalai to Thirukovilur Road ). So Top-up the Tank to check the mileage in Non-A/C. Vista drunk just
4.11 Liters. 100.4 Kms/ 4.11 L = 24.4 km/lit (Non A/C). I'm really Impressed. Vista Rocks in Mileage.
Again I tried to check the mileage with A/C. So, again top-up the diesel in Cuddalore . Distance covered from Veraiur to Cuddalore is 110Km. But, the Diesel man pressed the gun without checking the tank, so some quantity of diesel overflowed from the tank. Now Vista Drunk 7 liters of Diesel.
110km/7Lit = 15.7 Km/Lit (including excess diesel). This time Vista Drunk more, It may due to Cuddalore town traffic + state highway traffic.
I'm trying to check pure Highway mileage with A/C.but no time.
will check that one soon & let you guys know