I don't believe that luck has got anything to do with it. Several factors played the role in so good mileage.
1. Only 2 people on board
2. No luggage or other load in trunk or rear seat
3. I made it sure that ECO light keeps nearly always on, no sudden acceleration or brakes throughout.
P.S. Drove my father's 2012 Vitz to DG Khan a week ago (different vehicle than previously driven). Luggage in trunk and 5 people on board. A/C off & on. Didn't bother about ECO light. Speed kept between 90 and 120. Manually calculated mileage turned out to be 17.2 km/L.
50 % Fuel tank was filled with high octane and 50% was normal petrol.
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