What Does a Prime Mover Cost per Kilometre?

Key Takeaways

• Victoria's official 2025-26 cost schedule puts variable costs at $1.52 per km for a 10-year-old bogie drive prime mover: 91c for fuel, 10c for tyres and 51c for repairs and maintenance. That was with diesel at 184.5c/L.

• At $2.50/L, fuel alone is about 97c per km at 47 L/100km. That figure is after claiming back GST and the 21.3c/L fuel tax credit available to heavy vehicles from 3 August 2026.

• Kilometres decide your cost per km. In our example, a $150,000 used truck carries about $54,000 a year in fixed costs. That's 54c per km at 100,000 km a year, but 27c per km at 200,000 km.

• B-double registration costs $8,624 a year more than single-trailer registration. The 2026-27 charges are $14,313 and $5,689 for a 6x4. Register for multi-combination only if you pull B-doubles.

• Small fuel gains are worth real money. At 150,000 km a year, every 1 L/100km saved is worth about $3,090. Claiming fuel tax credits returns about $15,000 a year on a single-trailer truck.

What does it cost to run a prime mover per km?

For an owner-driver running a 10-year-old 6x4 prime mover at 150,000 km a year, our worked example comes to about $1.94 per km pulling a single trailer, and $2.26 per km pulling a B-double. That covers the prime mover only. It excludes trailer costs and the driver's own wage.

The figures below are built from the Victorian Government's 2025-26 Rates and Costs Schedule for a bogie drive prime mover, with fuel updated to 2026 prices and 2026-27 national registration charges. Every assumption is shown so you can swap in your own numbers.

Where the money goes

Retail diesel averaged about 247c/L across the five largest capitals in early August 2026, and terminal gate prices sat near 245c/L in late August. That's why the example uses $2.50/L. Diesel spiked to an average of 289c/L in April 2026, so check the current price before you quote.

The worked example

Variable costs barely change with distance. Fixed costs are what fall as kilometres rise, which is why a truck that sits idle two days a week costs far more per km than one that runs every day.

How does a new truck change the numbers?

Finance is the big difference. A $300,000 new truck financed over five years at 7.5% costs about $72,100 a year in repayments, against about $36,900 for the $150,000 used truck in our example. At 150,000 km a year, that adds about 23c per km.

Some of that comes back. A new truck under warranty, often with a service plan, will usually cost less than 51c per km in repairs in its early years, and newer engines tend to use less fuel. Ask each dealer for its fixed-price service plan cost per km and plug it into your own model. That's a better comparison than the sticker price.

Fuel tax credits: the cost most owner-drivers underclaim

The heavy vehicle road user charge recovers road costs from trucks over 4.5 tonnes GVM. Since 3 August 2026, it has been 32.4c/L. You don't pay it as a separate bill: it's taken off your fuel tax credit, which leaves 21.3c/L for diesel used in a heavy vehicle on public roads.

At 47 L/100km and 150,000 km a year, the truck burns about 70,500 litres. That's about $15,000 a year in fuel tax credits, claimed through your BAS. A B-double at 60 L/100km earns about $19,200. If your bookkeeper isn't claiming these, your real cost per km is overstated.

Which numbers move your margin the most?

• Fuel efficiency: 1 L/100km is worth about $3,090 a year at 150,000 km. A 5 L/100km gap between two trucks is worth about $15,400 a year. Ask for real-world fuel figures on your type of work, not brochure figures.

• Diesel price: each 10c/L rise costs a single-trailer truck about $6,400 a year at 150,000 km. Contracts without a fuel levy carry that risk entirely.

• Annual kilometres: going from 100,000 to 150,000 km a year cuts the cost per km by about 18c on the single-trailer example.

• Registration category: registering for B-doubles when you rarely pull them costs about $8,600 a year.

Turning cost per km into a rate

Your rate needs to cover the truck's cost per km, your trailer costs, your own wage, and a return on the money you've tied up in the business. The Victorian schedule notes that its figures leave out return on investment. The Victorian award rate for a semi-trailer driver in that schedule is $34.60 an hour, as a starting point for your own labour.

If your rate doesn't cover your cost per km at the kilometres you actually run, that's the signal to renegotiate, change trucks or rethink the work. To compare the running costs of specific trucks, request prime mover quotes and ask each dealer for real fuel figures and a service plan price. For purchase prices by class, see New Prime Mover Prices in Australia (2026).

Frequently Asked Questions

What is the average cost per km to run a prime mover in Australia?

Roughly $1.85 to $2.50 per km for the prime mover alone, depending on fuel use, kilometres travelled, the truck's age and finance. Our worked example comes to $1.94 per km for a single trailer at 150,000 km a year.

How much fuel does a prime mover use?

The Victorian cost schedule assumes 47 L/100km for a bogie drive prime mover. B-doubles commonly use 55 to 65 L/100km, depending on load, terrain and speed.

What is the fuel tax credit rate for trucks in 2026?

For diesel bought from 3 August 2026 and used in a heavy vehicle over 4.5 tonnes GVM on public roads, the fuel tax credit is 21.3c per litre. That's the full rate less the 32.4c road user charge.

How much does it cost to register a prime mover?

For 2026-27, a 6x4 prime mover costs $5,689 a year registered for single trailers, or $14,313 for B-doubles and larger. State insurance and fees are extra.

Is a new or used prime mover cheaper to run?

A used truck usually has lower finance costs but higher repair costs. A new truck costs more to finance but less to maintain in its early years, and usually uses less fuel. Compare total cost per km at the kilometres you'll actually run.