Fuel consumption I10 (1.1 l 69 hp )

My wife owns an I10 since Feb. 2013…5000 km running power about70% city….Question: I think the fuel consumption is quite high 8.3—-8.5 l…I was 2 times with the friendly master…..2 times he said I would see if there is an engine update….alleged …JA……after that the car actually consumed significantly less………what changed from tank filling to tank filling……..will the update be back again or am I stupid …..it’s still stupid ….. ………” mechanically “something has been changed……today !……who can help me……DANKE……for your help