VAAL TRIANGLE - South Africans will have another petrol price increase to calculate into their festive season budget. According to the Central Energy Fund, both grades of petrol will increase by approximately 22 cents per litre. Diesel will decrease by 15 and 16 cents per litre, and paraffin will decrease the most by 24 cents per litre. The increases are being accredited to the stagnating rand-to-dollar value and oil markets. The recent recovery the rand has experienced against the dollar has not been enough to encourage a decrease in petrol prices. The prices will come into effect at midnight tonight.