Petrol and diesel prices at Caltex stations will increase by 2 and 4 per cent today. Caltex, which owns 40 service stations, said the threat of war in the Middle East had caused prices to double in the last year. Vortex platinum petrol will be $11.96 per litre, while Vortex gold petrol and environmental diesel will be $11.21 per litre and $6.32 per litre respectively.