Looking at nations where that is a thing, I would say L/100km is less of a thing, in global world total number of people using km/L might actually be highest number, would like to see some proper statistic about this though, but to my dissapointment I could not find it. China I guess is exception in Asia and uses L/100km though, although I don't have solid evidence of this, but I found some official information where they used L/100km, then again so it is in India, except more generally they seem to use km/L. Same is true in Europe too in NL, lot of people use km/L even official standard is L/100km. Technically united states is not using imperial standards either, it was really long long time ago that they decided to move to SI system I believe, but in practice that has not happened. Anyway looking at nations and amount of population, km/L certainly is very important unit to have as it is south America, large part of Asia and areas of Europe where userbase is using km/L. It really bugs me that I could not find proper statistics about how many people use which system, you would think such statistics exists and would be readily available...
It's pretty simple tbh, if your car can do 20kmpl, which some cars can easily do, and if it has a 50l fuel tank, each litre of fuel you can do 20kms.. so basically the range is 1000kmpl, obviously irl there are other variables that change this, but ideally, it would be nuts.
kinda unrelated(?) but i used to take part in a championship where you built cars in automation and drive them in beam, and every time fuel consumption was scored they used km/L since it was the easiest to put in a spreadsheet so i'd say these people
Next time please read the thread you are about to reply to properly. This whole thread is specifically about km/L...