The UK has been going metric since the late 1960s, and at school and college we used the SI system - metre, kilogram, second.
Metric threads replaced the old BSW, BSF, BA and other measurements with their metric equivalents from the 1970s.
Petrol or diesel is proved in litres - has been for some years - although, oddly, supermarkets still insist on selling milk in 4.27 and 2.175 litre bottles (4-pints and 2-pints respectively).
Most cars can measure consumption in either litres/kilometre, or the ld style British imperial miles per gallon - the choice is yours largely.
Mind you - road signs are still in yds and miles - but we love a challenge in the UK.
I tried asking grandchildren about weights and measures recently, and they didn't understand how far a yard was - maybe they will be the generation that finally get rid of the bizarre multi-system measurements we have today.
But, please don't go back to inches, ounces, stones, chains, and furlongs - even I can't use them.