Picture by Michael Spencer
As part of its fuel price monitoring activities, the Australian Competition and Consumer Commission runs a weekly update on which day of the week fuel is cheapest in major capital cities. The fact that it's updated every seven days reflects the fact that longstanding ideas about the days when petrol is cheapest aren't necessarily accurate. If you've been sticking to the same day ("cheap Tuesday", perhaps) for years in the belief that it's cheaper, you're likely to have been wrong at least some of the time. On this week's update, Monday is the cheapest day in Sydney, Melbourne, Brisbane and Adelaide, while Perth's best day is Wednesday.
If you want more specific pricing information, Google offers a petrol-price tracking gadget which you can install on an iGoogle home page to search for the nearest cheap petrol and which updates petrol prices in many major locations twice a day. Motormouth, which provides that data, also offers an email update service. However, this isn't useful if you're not in the coverage areas,
The retail petrol market has been entirely transformed over the last decade by the emergence of supermarket chains as major players, offering discounts to customers who have spent a certain amount in those supermarkets. Those strategies often make sense, and indeed petrol discounts often represent better value than alternative strategies such as accumulating frequent flyer points instead.
However, there's a limit to how far those strategies can go. The ACCC has made it clear that major discounts (such as 40 cents off a litre, offered last year by a number of supermarkets) will only be tolerated as occasional loss-leader specials, not as a regular tactic.
A common consumer complaint is that a huge proportion of the cost of petrol comes from government taxes on fuel or gargantuan price gouging by oil companies. Neither is entirely accurate. In an assessment of petrol costs last year, the ACCC concluded that the three main factors which influence petrol prices are the raw cost of refined petroleum, Australia-US exchange rates and the weekly pricing cycle. By the ACCC's reckoning, Australia has the fourth-cheapest petrol in the OECD, and 90% of the overall price is comprised of raw fuel costs and taxes.
That said, other factors can come into play. The ACCC warned this week that supplies of ethanol-enhanced petrol will be affected because of the Queensland floods, which have had a major impact on the production of ethanol crops. That won't necessarily lead to price rises, but it could well lead to queues for ethanol-blended petrol.
What tactics do you use to get the best petrol price? Fuel up the comments with your ideas.
Lifehacker's weekly Loaded column looks at better ways to manage (and stop worrying about) your money.