Guide to fuel on long trips

Matt Williams — 2 July 2012

IT'S THE REMOTE distances and isolation of Australia’s outback that entices so many of us to load up the van and head bush to escape the hustle and bustle. Remote travel may cleanse the urban soul, but it presents some unique problems, none less than carrying enough fuel to keep your vehicle going.

Most modern 4WD tow tugs carry around 80 to 90L of fuel in standard form, while some carry up to 180L, and others as little as 70L. While vehicles can give 1000km or more on their own, that range is greatly reduced when towing a fully loaded rig. You can be sure that you won’t find a fuel station on every corner when you’re out bush, so you need to carry more fuel to get to those magic remote locations.


Temporary fuel capacity increases can be made to a vehicle and aren’t a bad idea if you’re only ever likely to need the added capacity for one trip, or that once-a-year expedition. The most common way is to carry fuel in jerry cans, or similar containers. Fuel should always be carried in a container specifically designed for that purpose and all fuel containers should comply with Australian Standard (AS) AS2906:2001.

Fuel cans can be made from metal or plastic and may be colour-coded – red for petrol and yellow for diesel – but they all need to meet the AS. If your fuel cans aren’t colour-coded it’s a good idea to clearly label them so everyone around knows what’s in them. You don’t want to end up like the traveller who ventured in to the desert with his diesel and water in the same style and colour of jerry can. Making his morning tea with diesel would have been preferable to topping-up his fuel tank with water when miles from mechanical assistance.

The common jerry can has close to 20L in capacity and gets its original design from German military fuel cans made from steel. This size and capacity has been replicated in plastic cans, which are easier to store and carry in holders on a roof rack, etc. Many plastic fuel cans also come with a pouring spout that makes life easier. A good quality poly jerry can will cost you somewhere around $60.

Wherever you carry your fuel cans they need to be thoroughly secured. It is best to avoid carrying fuel inside a vehicle, especially petrol, and always empty the fuel into the main tank as soon as possible. Even empty fuel cans carried inside pose a risk as the fuel vapour is still present. If a fuel can or tank needs to be carried inside a vehicle it should be secured in a fully sealed and ventilated compartment so that fumes or fuel cannot enter the passenger cabin. The driver should also ensure adequate fresh air ventilation.

Given some fuels are combustible on impact, fuel holders should never be attached to the rear of your van, or anywhere else they may be susceptible to impact, accidental or otherwise.

Another temporary solution is to carry the fuel in an auxiliary tank secured in a ute tray that may not be linked to the vehicle’s fuel system, but can be emptied into the main tank when needed. Again, this should be done as soon as possible.

Boab makes a range of universal-fit 55-60L polyethylene tanks ($295) specifically made for this use, while Poly RV accessories do upright 75L and 85L diesel tanks. If you’re concerned about poly or plastic tanks being suitable for fuel you should know that the OE tanks in many vehicles are made from plastic these days.

Large fuel tanks should not be mounted on roof racks, where the added weight is carried high and raises the tow vehicle’s centre of gravity, thus affecting handling and towing stability.

If you must carry fuel on a roof rack you are better off carrying it in multiple 20L jerry cans rather than in one large tank and, once again, these should be emptied in to the main fuel tank as soon as possible.

If you are carrying fuel in a separate tank or can, make sure you have a means of transferring it to the main tank, either by a siphon hose, jiggler or some sort of pump. It’s always a good idea to carry a jigger hose in your kit anyway; you never know when you’ll need it. I have had the electric transfer pump in an aftermarket auxiliary fuel tank fail on the Oodnadatta Track, and I had 90L of diesel in the second tank that I couldn’t shift to the main tank.


Fuel or fluids are best carried as low as possible in the vehicle to keep the moving mass low, and this is part of the reason OE fuel tanks are mounted as such. It is also why adding a permanently fitted larger tank and/or auxiliary tank under the vehicle can be a better and much safer option than temporary fuel containers.

These tanks are generally made from aluminised or stainless steel and manufacturers use computer-aided designs to make use of every available space under the vehicle to get the most fuel on board. Clever designs make allowances for leading and trailing edges of tanks so they are less likely to get hung up on obstacles.

“We design our tanks specifically for each vehicle, while keeping the design as simple as possible,” said Ric Black, from tank manufacturer The Long Ranger.

Ric said buyers should look for corrosion-resistant material and quality fittings in a tank. “Large flat sheets of metal are susceptible to metal fatigue caused by vibration,” he said. “Our tanks use various methods to add shape to the metal and strengthen it.”

Replacement and auxiliary tanks range in capacity from 50-200L, but most are around the 120-170L mark. Some companies make tanks that are split to carry both fuel and water. Having a drain plug in the tank can also come in handy if you cop some dodgy fuel and need to purge it from the tank.

Installing a larger tank in some vehicles requires the relocation or removal of items, such as the spare wheel or exhaust system, to accommodate the bigger tank(s). You need to be aware of this as it will add extra cost with something like a rear-wheel carrier or new exhaust system.

The laws differ around the country, but some states require an engineer’s certificate for the installation of an auxiliary or bigger tank. The only real requirements for aftermarket tanks are that they meet the same quality and standards as OE, have a rollover valve fitted to prevent leakage in an accident, and allow for five per cent expansion.

Purchase your tank from one of the major manufacturers or retailers and ask them about the specifics for your state. If you’re still unsure consult a vehicle engineer.


A replacement fuel tank will generally be a fit-and-forget addition that is filled and emptied just like a standard fuel tank. A second (auxiliary) tank, however, requires a filler and a means of transferring the fuel to the OE fuel system. As such, an auxiliary tank is usually more expensive, and you can expect to pay between $1000 and $2000 depending on the size and vehicle type.

On some vehicles, the extra filler can be integrated into the standard fuel filler with a Y-piece, while others need a second filler neck. In some cases the second filler can be mounted directly alongside the OE filler behind the standard filler flap, but other vehicles require a totally separate filler neck and modifications to the bodywork.

Auxiliary fuel tanks use a transfer system where once the main tank is low the driver switches the system to refill the main tank. Sometimes this is a gravity feed or siphon flow, but most use a small electric transfer pump. The driver needs to be aware of when the fuel is being transferred to know when to turn the pump off, so it’s a good idea to have a fuel sender and gauge on your second tank.
Some auxiliary fuel tanks require an extra fuel gauge to be installed while others use the OE gauge.

Many of the cheap tanks don’t even have a sender unit, so you never know what’s in your auxiliary tank – be sure to check out what’s in the setup you may be about to buy.


Having a larger fuel capacity has its advantages in town as well as in the bush. It allows you to take advantage of cheaper fuel prices, discount vouchers and any weekly fuel price cycles. But you need to bear in mind that carrying 200L of fuel around town adds almost 200kg of weight.

When in the city I generally use the main tank and only fill the auxiliary when going on trips, using fuel vouchers. The $0.04/L saving adds up to a couple of schooners at the end of the day when you’re buying 150L or more.

A steel tank permanently mounted under your vehicle might be a more expensive option than jerry cans or temporary tanks, but it’s by far the safer and more practical choice. You avoid the dangers of filling and transferring fuel from drums or jerries, as well as the possible contamination when filling up on the side of a dusty track. The fuel is carried in a solid tank that is low on the vehicle so the effect on handling and towing your van is minimised.

The added capacity and range will broaden your travelling horizons, allowing you to venture to more remote and exciting places in the great Australian outdoors.


Static electricity poses a real risk of igniting fuel whenever you are filling up, but it’s particularly prevalent if you are filling a container that’s off the ground, such as on the back of a ute. Not advisable.
At many country fuel stations you will see an earth lead by the diesel pump, which needs to be attached to fuel drums when they are being filled.

This is mainly for the cockies filling up their 200L drums on traybacks, but equally applies to filling any fuel container. The Confederation of Australian Motorsport (CAMS) has some good safety information on filling fuel containers on its website. Visit and follow the relevant prompts.


However you carry extra fuel you have to remember that you are adding weight to the vehicle and this must be done while staying under your GVM, which is the maximum legal weight of the vehicle, fully loaded and fuelled, as set by the vehicle manufacturer. Also bear in mind the GCM.

Fitting an extra 70L tank could be adding more than 100kg to your vehicle when the tank is full. With many rigs already pushing their GVM when fully accessorised and loaded, added fuel capacity is another weight that must be considered.

If you are carrying fuel in jerry cans on the roof you should also be mindful of the capacity of your rack and roof, which could be a little as 50kg. An overloaded roof rack is prone to breakage on rough, corrugated roads which could possibly lead to a disaster.

WORDS Matt Raudonikis
Source: Caravan World Jan 2011 


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