In the UK, where gas is gaseous and vehicles run on petrol, LRP is an abbreviation for Lead Replacement Petrol. EU law decreed that regular (ie not unleaded) fuel could no longer be sold after January 1, 1999 which would have caused problems for owners of older cars which couldn't easily be converted to run on unleaded fuel. The oil companies' response was to introduce LRP: apparently as good as leaded 4-star petrol and useable in all except for pre-War cars, so quite why they never managed to present it as a solution in the first place is something of a mystery, especially given that the full introduction of unleaded fuel has meant more and more cars using catalytic converters which create far more pollution and environmental damage than leaded fuel ever did.