How PetrolSaver Works

We believe you deserve to know exactly how we recommend fuel stations. No black boxes. Here's the complete breakdown of our recommendation engine.

1Where our data comes from

All fuel price data is sourced from the Victorian Government's Fair Fuel Open Data API, operated by Service Victoria.

Fuel retailers across Victoria are required to submit their prices to this system. The data is published with a ~24 hour delay to protect commercially sensitive information.

We refresh our data every hour and do not modify the prices in any way. What you see is exactly what the government publishes.

We currently track approximately 1,600+ fuel stations across Victoria.

2How we rank stations

We don't just show the cheapest station. We calculate the true cost of filling up at each station, factoring in the real cost of getting there.

Our algorithm considers three factors:

$
Price per litre

The raw price at the pump, as reported by the retailer.

Detour distance

How much further you'd need to drive compared to the nearest station. We estimate road distance at 1.35× the straight-line distance and calculate the fuel you'd burn on the detour (assuming 8.5L/100km average consumption).

Your fuel level

How much fuel you told us you have. This affects two things: how far we'll recommend you drive (we cap the search radius at 70% of your remaining range for safety), and how many litres you'll actually fill (which determines your real dollar savings).

3The maths

For each station within your range, we calculate:

// How much extra you'd drive (nearby mode)
detour_km = (distance_to_station - distance_to_nearest) × 2
// How much extra you'd drive (trip mode)
detour_km = (you → station → dest) - (you → dest)
// Fuel burned on the detour
fuel_cost = (detour_km ÷ 100) × 8.5 × station_price
// How full is your tank (based on range slider)
tank_percent = your_range_km ÷ 800
// How many litres you're filling
litres_filling = tank_size × (1 - tank_percent)
// Raw savings vs nearest station
price_savings = (nearest_price - station_price) × litres_filling
// What you actually save
net_savings = price_savings - fuel_cost

We then rank stations by net savings — the amount you actually save after accounting for the fuel cost of getting there.

4What the labels mean

BEST VALUE

Highest net savings after detour cost. The smartest pick — balances price vs distance.

CHEAPEST

Lowest raw price per litre within your range. Might be further away but has the biggest price drop.

CLOSEST

The nearest station to you. Shown for convenience — useful when you're low on fuel or in a rush.

AVOID

The most expensive option nearby. Shown as contrast so you can see what you'd waste. Not clickable.

5Price colours explained

Prices are colour-coded relative to all stations in Victoria for your selected fuel type, not against fixed thresholds. This means the colours adjust as market prices change.

219.9¢Top 10% cheapest — great price
239.9¢Top 10–50% — average price
269.9¢Bottom 50% — above average

6Trip mode

When you set a destination, we filter stations to those roughly along your route — not just the closest by distance.

We define “along your route” as any station where the total distance (you → station → destination) adds no more than 15% to the direct distance, with a minimum corridor of 5km. This prevents recommending stations that are cheap but in completely the wrong direction.

The detour calculation in trip mode is:

detour = (you → station → destination) - (you → nearest → destination)

7Assumptions we make

Tank size55 litres
Fuel consumption8.5 L/100km
Road distance factor1.35× straight line
Average city speed35 km/h
Safe detour range70% of remaining fuel
Max search radius15 km
Full tank range800 km
Litres to filltank × (1 - range/800)

These are averages for a typical passenger car in metropolitan Melbourne. Your actual savings may vary based on your vehicle's fuel efficiency, traffic conditions, and the actual road route taken.

8Independence

PetrolSaver is not affiliated with any fuel retailer or brand. We do not receive payments or incentives from any fuel company to promote their stations.

Our recommendations are based purely on the algorithm described above. The only revenue we earn is through advertising displayed on the site.

The price data is published by the Victorian Government and we are required by the API terms of use to display it without modification.

Data from Service Victoria · Prices delayed ~24hrs