Tribune News NetworkDohaAnnouncing the fuel prices in Qatar for September, Qatar Petroleum on Tuesday said premium-grade petrol will cost QR2 per litre, while the super grade petrol will retail at QR2.05 per litre. Both fuel grades saw a decline of 5 dirhams in their fares from August.Diesel, on the other hand, is priced QR1.85 per litre for January, QR0.10 less than its price in August.