Fuel prices might seem a little lower than usual where you live right now. 

Earlier this month, two global petrol price bodies lowered their global oil demand growth forecasts, citing lower demand for oil in China and its push towards renewable energy. 

But, depending on where you are, it's not just international forces dictating the cost of fuelling up. 

Drivers in five capital cities — and a few major regional centres — are beholden to what industry experts call petrol price cycles.

And, based on Australian Competition and Consumer Commission (ACCC) charts, they can expect to see prices go up again.

What are petrol price cycles?

They're patterns of petrol prices.

When you record the average petrol price each day and plot those figures on a graph, they appear to go up and down according to a regular cycle. 

Usually, they increase sharply in a shorter space of time, then gradually decline over a longer period, a report from the ACCC says. 

Importantly, we're talking about the average prices here — because not all service stations follow the cycle. 

But enough of them follow the trend for it to impact drivers' budgets. 

This is something that has frustrated industry experts for years, National Roads and Motorists' Association (NRMA) spokesperson Peter Khoury says.

Mr Khoury remembers back in 2009 petrol prices in some cities would typically be at their lowest on a Tuesday before steadily climbing as the weekend approached. 

It meant that, if drivers paid close attention to these cycles, they could predict the cheapest days to fuel up — and plan around that to save money.

"We started to see a significant shift in how those price cycles work," Mr Khoury says. 

"As a result, they've gone from days to weeks."

And the longer the price cycles are, the longer drivers are exposed to higher prices. 

In 2018, the average price cycles in Brisbane, Sydney and Melbourne were about a month. 

But by last year, they increased to almost seven weeks, an ACCC report in August revealed. 

Which cities follow petrol price cycles?

The ACCC tracks the following capital cities:

• Adelaide
• Brisbane
• Melbourne
• Perth
• Sydney

It says these price cycles are not being seen in Canberra, Darwin or Hobart. 

However, Mr Khoury says petrol price cycles seem to be appearing in some larger regional centres. 

Where are we at in the cycles?

The ACCC has a website dedicated to tracking the daily average prices for regular unleaded petrol in those five capital cities. 

These ACCC graphs show the 45-day pricing trends from mid-August up to Wednesday.  

Adelaide:

Brisbane:

Melbourne:

Perth:

Sydney:

What drives price cycles?

"These cycles are the result of pricing decisions made by various petrol retailers," the ACCC report says. 

"Price cycles only occur at the retail level and are not driven by movements in wholesale prices or underlying costs; wholesale prices do not exhibit similar cyclical movements."

How can I make price cycles work for me?

Knowing where you're at in a price cycle can help you make decisions about whether you should fill up your car or just top up until prices drop further. 

And this could save you money in the long run. 

"There are very long high points [in the cycle]," Mr Khoury says. 

"But there are still low points."

Mr Khoury says you should try to hold off filling your tank until a low point in the cycle.

And when you're at a high point in the cycle, top up with smaller amounts instead of committing to an entire tank of petrol at that price. 

So check the ACCC's cycle-tracking website before you head to the service station.  

Here are some other tips from the ACCC:

In Adelaide, where possible, monitor price cycles closely as there can be around two weeks between low points. 

In Perth, if possible, buy on Tuesdays, the cheapest day of the weekly price cycle.

To counter longer price cycles in Sydney, Melbourne and Brisbane, shop around when prices start to increase as not all sites increase prices at the same time, and there is often a significantly lower priced retail site around.

Shopping around doesn't have to mean driving from one servo to another — petrol price comparison apps and websites can help you decide where to go before you start your engine. 

Some states and territories have their own government-run online tools to help drivers shop around. 

State fuel price reporting schemes

With the exception of Victoria, every state and territory has a petrol price reporting scheme aimed at saving drivers money. 

Most of them include a state-run app allowing drivers to compare petrol prices. 

Here's a state-by-state breakdown of the schemes:

ACT and NSW:

Drivers in New South Wales and the Australia Capital Territory can use Fuel Check to compare prices. 

It works as both a website and an app.

Northern Territory: 

The NT has a website that publishes fuel prices in real time called MyFuel. 

All fuel retailers in the territory must report prices under the scheme. 

Queensland:

Queensland requires fuel retailers to report prices, but does not have a state-run app. 

Instead, the state government website points drivers to a list of more than a dozen different websites and apps to compare fuel prices. 

South Australia:

South Australia's version of a fuel price scheme does not include a government-run website or app. It relies instead on existing fuel price apps. 

The scheme does require service stations to report prices to "a central database" within 30 minutes of changing prices.

Tasmania:

The Tasmanian scheme has an online tool called FuelCheck TAS. 

It provides real-time updates on fuel prices in the state and can be used as a website or downloaded as an app on your device. 

Victoria:

There is no state-administered scheme in Victoria. 

However, drivers are able to use other publicly available price-tracking websites and apps. 

Western Australia:

Western Australia's version of this is called Fuel Watch. 

Throughout most of the state, fuel stations have to lock in the day's prices and notify Fuel Watch of their price by 2pm the previous day. 

The prices kick in at 6am and must remain in place for 24 hours.