Why does the price of diesel stay the same, while petrol prices go down?
While the retail prices of both diesel and ULP track international prices, ULP is a much more competitive market. This means that in the short-term, the price of ULP in metropolitan areas is subject to a regular price cycle. Diesel prices do not follow a cycle, so are more stable. During a petrol price cycle, the difference between ULP and diesel is subject to wide variation. Perth diesel prices are generally higher than Perth ULP prices, due to the much smaller, and less competitive, market.