Seat Leon

Hello, I want to buy a Seat Leon. I do not know which class is recommended.. my selection is limited to one that should not cost more than 15 tsd and preferably less than 20,000 km. Now there is e.g. the 1.6 row with 102 ps for approx. 14,500 with 7,6l combined and 183g co2 boost in consumption where I ask myself if it can be that I in the 1.4 tsi row often for the same price with 6,3l and 150g co2 in consumption with similar properties with 125 ps and less Ki lometer (in this case) is offered… does the 1.6er have a better engine or does it go away better? I don’t know so much and wonder why a car with 75 kw consumes so much more than one with 92… for every purchase tip I say thank you..