For both in the UK I don't think there were "shortages" where it wasn't available. Both just shoot up in price (like they always do at the merest hint of supply shortages or whalesale cost increases ..)
Similar issue in France: strikes were happening leading to local constraints, which was then amplified by people rushing to fill their tanks. In both cases, the situation comes back to normal after a few weeks.
This is the toilet paper shortage, or the bank run, all over again.
No one calls it petroleum - petrol is what anyone on the street would call it. Diesel is different and just called diesel. I don't know why or how this started - guessing some old thing that wasn't-quite-right but which stuck around regardless
Tbh 'gas' is the weird one, it's a liquid.
'The term is thought to have been influenced by the trademark "Cazeline" or "Gazeline"', then becoming 'gasolene' before ending up as 'gasoline', shortened as 'gas'.