In May 2023, fuel in Belgium averaged €1.713 for petrol

Petrol, monthly average€1.713/L
Diesel, monthly average€1.652/L
LPG, monthly average€0.607/L
Weekly bulletins held for May 20235

Monthly averages for Belgium across May 2023, from the stored EU Weekly Oil Bulletin monthly history (European Commission, CC BY 4.0).