Fuel consumption - is this accurate?

[Daniel1]

For the first few months that I owned my Ford Focus 2015 Titanium X, I was getting around 5 L/100km (57 UK mpg) fuel consumption, and it stayed pretty consistent,+ - .2 or so.

Over the last month or two though, it seems to have been plummeting, and today I am sitting at 2.7 L/100km (105mpg).

I do try to drive very efficiently, and I live in the countryside, meaning most of my drives are mostly non-stop on a country road. But this just seems way too good to be true, and obviously it wasn't the case in the first few months.

Can this actually be accurate? I haven't measured exactly, but I do seem to be getting about 1000-1200km on a full tank. Next time I fill up, I will calculate exactly how many L the car has and how many km I get in total.