In January 2018, fuel in Slovenia averaged €1.308 for petrol

Petrol, monthly average€1.308/L
Diesel, monthly average€1.255/L
LPG, monthly average€0.670/L
Weekly bulletins held for January 20185

Monthly averages for Slovenia across January 2018, from the stored EU Weekly Oil Bulletin monthly history (European Commission, CC BY 4.0).