THE petrol price is to rise by 8c a litre on Wednesday. The Department of Mineral and Energy Affairs said on Friday that the wholesale price of diesel will decline by 6c a litre and that of illuminating paraffin will drop by 4c per litre. From Wednesday, 93 octane will cost R3,31 per litre in Gauteng, and R3,20 at the coast. Diesel will cost R2,71 per litre in Gauteng and R2,60 at the coast, while illuminating paraffin will cost R2,00 a litre in Gauteng and R1,84 at the coast.