Petrol averaged $2.35 a litre nationally in the week to 8 November and diesel was close to $2.78. Wholesale prices have since fallen further, but motorists are still paying substantially more than they were in February.

Australian motorists got some relief at the bowser in early November. For someone buying 60 litres, the national price falls amounted to a saving of about $1.74 on petrol and $1.08 on diesel compared with the previous week.

That puts the latest falls in perspective. Using the competition regulator’s figures for the five largest capitals, a 60-litre fill on 4 November cost about $37 more for petrol and $60 more for diesel than it did on 20 February, before the Middle East conflict escalated.

Wholesale prices have since come down further. How much of that drop reaches the bowser, and how quickly, is the next test.

What Australians are paying

The Australian Institute of Petroleum reported that the national average petrol price fell 2.9 cents to 234.5 cents a litre in the week to 8 November. Diesel fell 1.8 cents to 278.3 cents a litre.

The petrol price varied considerably across the country. Perth averaged $2.23 a litre, Adelaide $2.24, Sydney $2.32 and Melbourne and Brisbane about $2.34. The national regional average was close to $2.40. In regional Northern Territory, it was about $2.86.

For someone buying 60 litres, that works out to about $134 at Perth’s weekly average and $172 at the regional Northern Territory average. A national price can tell motorists which way the market is moving. Where they fill up determines what comes out of their budget.

Wholesale prices have fallen further

From 6 to 12 November, benchmark wholesale petrol prices fell by about 13 cents a litre in Sydney, Melbourne, Brisbane, Adelaide and Perth. Wholesale diesel fell by about 6 to 7 cents a litre in those cities.

A 13-cent fall would save a driver nearly $8 on 60 litres if it were passed through in full. Retail prices can take time to reflect wholesale changes as service stations turn over stock and adjust to what competitors nearby are charging. Freight and operating costs also influence what a station can sell fuel for, particularly in towns with fewer outlets.

There is a further complication in the five biggest capitals. Petrol retailers can raise prices sharply at the start of a new price cycle even as wholesale prices are easing. A driver who sees the price jump at one station may still find a substantially cheaper fill nearby. Diesel generally moves without that regular retail cycle.

Why diesel is still the bigger problem

Diesel averaged about 44 cents a litre more than petrol nationally in the week to 8 November. For a 60-litre purchase, the difference was about $26. For a business buying 1,000 litres, a 10-cent change alone means $100 on the fuel bill.

Petrol and diesel each have their own international refined-fuel benchmark. Crude oil matters to both, but the supply of each finished fuel and demand for it can move differently. The Australian dollar matters too. When it weakens against the US dollar, it can absorb some of the benefit of a fall in overseas fuel prices.

Diesel also reaches people who never buy it. It powers trucks that carry groceries, machinery that works farms and vehicles used by trades and service businesses. How quickly a lower diesel price reaches customers depends in part on when freight rates and fuel surcharges are reset.

The Times View

The wholesale decline through 12 November gives motorists a reason to look for cheaper fuel in the next round of retail figures. The bigger question is whether diesel keeps falling and whether the savings reach regional towns as well as the capitals.

A few cents off petrol helps with the next fill. A sustained fall in diesel would reach further, from the cost of sending a truck across the country to the cost of getting fresh food onto the shelf.