How does the fuel efficiency calculator work?

It compares the extra fuel your car burns driving to a cheaper station against the savings from that station’s lower price. If the cents you save per litre, multiplied by the litres you fill, outweigh the cost of the extra round-trip distance, the drive is worth it.

What counts as a worked example?

Say a station 4 km further away (8 km round trip) is 6 cents per litre cheaper and your car uses 8 L/100 km. The detour costs about 0.64 litres of fuel — roughly the price of 1 litre at most pump prices. Filling more than about 11 litres at the cheaper station already covers that cost, so a typical 40-litre fill puts you well ahead.

Does this replace the diesel vs petrol calculator?

No — this tool answers "is the further servo worth the drive" for a single fuel type. Use the diesel vs petrol calculator separately to compare annual spend between two different fuel types.

Fuel Efficiency Calculator

Is it worth driving to a cheaper station? Enter your vehicle's fuel consumption, distance and prices to see the break-even fill and whether you'll save.

Your details

Nearest station price (¢/L)

e.g. 180.5

Cheaper station price (¢/L)

Must be less than nearest

One-way distance to cheaper station (km)

Vehicle fuel consumption (L/100 km)

Check your car manual or trip computer

Litres you plan to fill (optional)

Leave blank to see break-even volume only

Result

Fuel used for round trip0.80 L

Cost of driving there and back$1.32

Minimum fill to break even8.8 L or more

If you fill at least 8.8 L at the cheaper station, you save money after accounting for the extra fuel used to get there and back.

How it works

The calculator uses the extra fuel your car uses for the round trip to the cheaper station. If the savings on the fuel you buy there are greater than that cost, the trip is worth it. We show you the minimum litres you need to fill to break even; if you plan to fill more, you save.

Worked example: a station 4 km further away (8 km round trip) is 6 cents per litre cheaper, and your car uses 8 L/100 km. The detour burns roughly 0.64 litres of fuel — about the price of one litre at most pump prices. Filling more than around 11 litres at the cheaper station already covers that cost, so a typical 40-litre fill puts you well ahead.

Tip: use your trip computer or manual for L/100 km, and compare today's prices from our station directory. If you're comparing diesel against petrol rather than two petrol stations, use the diesel vs petrol calculator instead.

Frequently asked questions

How does the fuel efficiency calculator work?: It compares the extra fuel your car burns driving to a cheaper station against the savings from that station’s lower price. If the cents you save per litre, multiplied by the litres you fill, outweigh the cost of the extra round-trip distance, the drive is worth it.
What counts as a worked example?: Say a station 4 km further away (8 km round trip) is 6 cents per litre cheaper and your car uses 8 L/100 km. The detour costs about 0.64 litres of fuel — roughly the price of 1 litre at most pump prices. Filling more than about 11 litres at the cheaper station already covers that cost, so a typical 40-litre fill puts you well ahead.
Does this replace the diesel vs petrol calculator?: No — this tool answers "is the further servo worth the drive" for a single fuel type. Use the diesel vs petrol calculator separately to compare annual spend between two different fuel types.

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