Im hypothesising no. We’ve got 2 fords, filler is on opposite sides.
Let me guess; left is a Fiesta / Ka, right is a Focus / Mondeo?
The petrol cap is on the opposite side of the diesel cap.
That’s not true either I don’t think (why would it be? Makes no sense). But y’know, those wacky French have some unconventional ideas.
I expect it’s manufacturer-specific. Most will default to the left as that’s the majority market; some manufacturers will bother to change it for the RHD market, and in the case of Ford they’ll only do it on the bigger (ie, more ‘premium’ vehicles. I’m purely guessing, but I bet given my i40 is on the left, all Hyundai fillers are on the left globally.
That’s my theory, and it’s held true for pretty much everything I’ve driven. But the only thing I can say with any certainty is, it’s wherever they choose to put it.