agreed bro, this bhai jee is actually talking about his the opposite way. Mileage figures technically and practically improve as the engine ages.
I met this friend of mine who owns a city 2010 driven 50k kms. He said the car is sluggish and sucks at fuel economy. He was told to ge tuning done. So, he got "something" done to his car and came back like this sucks man, tuning didn't work!
I drove the car, asked him about the tuning thing, he said filter saaf hain, plugs achay hain bla bla. Ye dekho (popped the hood and showed me the filter) bilkul new aue white hai.
When I turned it over, it was as black as ROAD TAR! Literally!
We drove the car without the filter and 75% of he problems went away! Thats what people do around here and then complain about car's not delivering upto he mark.