That’s called “an American drives to Canada”. Is $4/litre expensive? Wait, before you answer, those are also Canadian dollars, so don’t forget the exchange rate. Now, how much, using U. S. dollars, to fill up an eight gallon motorcycle tank?
I have my car set to display L/100km, but that's mostly because it's a hybrid and so kW/100km is more logical than the inverse and it makes sense to have them both operating the same way.
My previous car didn't have an economy reading anyway, so my only frame of reference before was calculating pence per mile rather than MPG. L/100km seems logical and I had got used to it in a matter of weeks. Mine is generally around 5-6L/100km on long, mostly petrol journeys, so this is now my new mental benchmark, and it's also trivial to go from this to pence per litre, and not much more to get to the pence per mile that I thought in before. I guess my brain has got good at multiplying by 1.6 as I use km for running and cycling too.