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
Our fuel price data comes from two government sources:
- Victoria: The Victorian Government's Fair Fuel Open Data API. Prices are delayed ~24 hours.
- New South Wales: The NSW FuelCheck API via Transport for NSW. Prices are updated in real-time.
Fuel retailers in both states are required to submit their prices to these systems. We refresh our data regularly and do not modify the prices in any way. What you see is exactly what the government publishes.
We currently track approximately 4,000+ fuel stations across Victoria and New South Wales.
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:
The raw price at the pump, as reported by the retailer.
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 using your vehicle's consumption rate.
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:
We then rank stations by net savings — the amount you actually save after accounting for the fuel cost of getting there.
For every recommendation with a detour, we show you the break-even distance — the maximum detour where the cheaper price still saves you money. If the station is within this distance, the detour pays off. If not, you're better off filling up closer.
This is why a 20c saving doesn't always justify driving across town. The break-even metric helps you decide at a glance whether a detour is truly worth it for your situation.
When you expand a station, you see a full breakdown table. Here's what each row means:
On desktop, hover the ⓘ icon next to any row for a quick explanation.
4Detour cost: fuel only vs full cost
When we calculate how much a detour costs, you can choose between two models via the More filter chip:
Only counts the petrol burned on the detour. Cheapest interpretation — a 5km detour at $2/L costs about $0.85. Best if you only care about out-of-pocket fuel cost.
Uses the Australian Tax Office's cents-per-kilometre rate, which covers fuel plus tyres, servicing, insurance, registration, and depreciation. The same 5km detour now costs $4.40. This dramatically changes whether a detour is worth it.
Rate: 88c/km for 2025-26. ATO source
Why it matters: A 20c/L price saving on a 40L fill is $8. At fuel-only rates, that saving justifies a 47km detour. At ATO rates, it only justifies 9km. Most people underestimate the true cost of driving — the ATO mode gives you the honest picture.
5What the labels mean
Best value after factoring in the drive. The top-ranked station — best balance of price, distance, and your fill amount.
Solid saving — the detour pays off. Cheaper than the closest station with positive net savings after detour.
Nearest servo to you. Shown for convenience — useful when you're running on fumes or short on time.
Label colours match the station's price tier — green for cheap, amber for mid-range, red for expensive. Stations are ranked by true cost (price + detour), not just raw price.
6Price colours explained
Prices are colour-coded relative to all visible stations for your selected fuel type, not against fixed thresholds. This means the colours adjust as market prices change.
7Trip 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:
8Assumptions we make
Tank size and fuel consumption come from your vehicle profile (set via the Car chip). If you haven't set your vehicle, we default to a Toyota Corolla Hatch (50L tank, 6.8L/100km). Road distance is estimated at 1.35× straight-line distance — actual routes may differ.
9Price trends — “Fill now” vs “Wait”
At the top of your station list, you'll sometimes see a banner telling you whether to fill now or wait. Here's how we work that out.
Every day, we snapshot the price at every station in our database. We then compute the daily average across all stations for your selected fuel type. With 7+ days of data, we can detect whether prices are trending up, down, or sideways.
The last 3 days show an upward trend of more than 1c/L. Today's average is higher than yesterday's. Prices are likely to keep climbing — fill up sooner to avoid paying more.
The last 3 days show a downward trend of more than 1c/L. If you can wait a day or two, you'll likely pay less. Australian fuel prices often follow weekly cycles — they spike early in the week and bottom out mid-week.
Prices are within 1c of the weekly average. No strong trend either way — fill when convenient.
Important: This is based on historical averages, not a crystal ball. External events (oil price changes, public holidays, supply disruptions) can override normal patterns. Use it as a guide, not a guarantee.
Tap the trend banner to expand it and see the daily breakdown — today's price, yesterday's, the 7-day average, and a sparkline showing the trend visually.
10Independence
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 and NSW governments and we are required by the API terms of use to display it without modification.