Fuel Costs On The Big Lap: What To Expect & How To Save

Fuel is the one Big Lap expense you can’t eliminate. You can free camp to dodge accommodation costs, cook every meal to cut food bills, and skip paid activities to save on entertainment. But the van isn’t going to tow itself around Australia. A typical Big Lap covers 20,000 to 40,000km, and at 14 to 22L/100km while towing, that’s 3,000 to 8,800 litres of diesel. At $2.00/L, you’re looking at $6,000 to $17,600 in fuel over the entire trip. The range is wide because the variables are significant, and understanding them helps you land at the lower end.

Fuel is the one cost you can’t avoid. But you can reduce it significantly with the right habits.

What Fuel Actually Costs When Towing

Forget what your vehicle does unladen. Towing adds 30 to 60% to your fuel consumption. A vehicle that does 10L/100km on the highway will do 14 to 16L/100km towing a light van and 18 to 22L/100km towing a heavy one. The difference between these consumption rates over 30,000km is enormous.

The difference between a light, efficient setup (14L/100km) and a heavy rig (22L/100km) is $4,800 to $5,520 over 30,000km. That’s a meaningful chunk of your total budget, and it’s determined before you leave the driveway by your choice of vehicle and van.

The Variables That Affect Your Fuel Bill

Van weight. The heavier the van, the harder the engine works, the more fuel it burns. A 1,500kg van costs significantly less to tow than a 2,800kg van over the same distance. This is one of the strongest arguments for a lighter setup if budget is a priority.

Speed. The single most controllable variable. Air resistance increases exponentially with speed, and when you’re pushing a caravan through the air, the effect is dramatic. Dropping from 110km/h to 95km/h reduces fuel consumption by 10 to 15%. Over 30,000km at 18L/100km, that’s 540 to 810 fewer litres, saving $1,080 to $1,860.

Terrain. Flat highways (Nullarbor, most of Highway 1) are the most efficient. Hilly terrain (Great Ocean Road, Tasmanian roads, ranges in NSW and QLD) increases consumption by 10 to 20%. Unsealed roads increase consumption by 15 to 30% due to lower speeds, rougher surfaces, and reduced tyre efficiency.

Wind. A headwind of 20 to 30km/h can increase consumption by 10 to 20%. Crosswinds are less impactful on consumption but harder on the driver. You can’t control wind, but you can plan travel days around weather forecasts and avoid driving into known prevailing winds.

Tyre pressure. Underinflated tyres increase rolling resistance and fuel consumption. Check and adjust pressures before every drive, accounting for load and road surface. Correct pressures improve both fuel efficiency and tyre life.

Remote Fuel: The Premium You Can’t Avoid

Fuel in remote Australia costs more. Sometimes significantly more. In capital cities and major regional centres, diesel is typically $1.80 to $2.20/L. In remote areas, $2.30 to $2.70/L is normal. In genuinely isolated roadhouses, $3.00+/L is possible.

Where the premiums are worst: The Stuart Highway north of Alice Springs, the Gibb River Road fuel stops, Cape York communities, outback WA between Geraldton and Broome, and isolated roadhouses across the Nullarbor and SA outback. Any location where fuel arrives by road train rather than pipeline charges accordingly.

How to manage it: You can’t avoid remote fuel entirely; the Big Lap goes through remote areas. But you can minimise the impact. Fill up at the last major town before entering a remote stretch. Carry extra fuel in jerry cans if your vehicle is set up for it (check weight limits). Track consumption carefully so you know your range and don’t panic-fill at the first overpriced roadhouse.

$2.65/L diesel at a remote roadhouse is the cost of adventure. Fill up before you get there and the sting is smaller.

How To Save On Fuel

Slow down. Already covered but worth repeating because it’s the biggest single saving. Dropping 15km/h saves more money than any app, loyalty card, or driving technique combined.

Use fuel price apps. GasBuddy, FuelMap, Petrol Spy, and MotorMouth all show real-time fuel prices. The difference between the cheapest and most expensive station in a regional town can be 15 to 25 cents/L. On a 150L fill, that’s $22 to $37 saved per fill. Over a year of fortnightly fills, that’s $570 to $960.

Loyalty programs. Woolworths Everyday Rewards gives 4 cents/L off at selected stations. Coles Flybuys linked to Shell offers similar savings. RACQ, RACV, and other motoring clubs offer fuel discounts at selected stations. These savings are modest individually ($6 to $8 per fill) but compound over a long trip to $300 to $500.

Plan your distance. Drive fewer kilometres. It sounds obvious but many Big Lappers cover unnecessary distance by backtracking, taking detours on impulse, or driving to a town for supplies when a closer option exists. A planned route with efficient legs saves fuel.

Maintain your vehicle. Clean air filters, correct oil, properly inflated tyres, and a well-serviced engine all contribute to better fuel economy. A neglected engine can use 5 to 10% more fuel than a maintained one.

Planning Your Fuel Stops

Know your range. Calculate your vehicle’s range while towing: tank capacity ÷ consumption × 100 = range in km. A 140L tank at 18L/100km gives you 778km of range. In practice, plan to refuel at 75% of your theoretical range to allow margin for headwinds, detours, and inaccurate fuel gauges.

Use Hema Maps. Hema Maps shows fuel stops across Australia, including remote roadhouses and their opening hours. Some remote fuel stops close at 4pm or are only open certain days of the week. Running dry because the roadhouse was closed is an avoidable disaster.

Carry extra fuel on remote legs. If your route includes stretches where fuel stops are 400+km apart, carry a jerry can (20L). This adds 100+ km to your range and removes the anxiety of running low. Check your vehicle’s payload capacity before adding the weight (20L of diesel weighs roughly 17kg).

Hema Maps shows every fuel stop in the country, including remote roadhouses. Plan your fills before you need them.