How to: Increase your fuel range


The fuel tanks of most 4x4s give you a range of between 400 and 600 km, depending on your driving style and the type of terrain you’re doing.
But if the desert and remote destinations are your kind of thing, you probably should consider a long-range tank. We went to LA Sport’s Cape Town workshop and watched while they fitted a Frontrunner auxiliary tank to a 4.0 V6 Hilux 4×4 double cab.

The sizes of these tanks vary from vehicle to vehicle as they’re designed to fit into the available space. Quite often the space between the spare wheel and the load bay is used for this. And because all vehicles are different, a tank’s size depends on the vehicle it was designed for. For example, the Frontrunner tank fitted to a Hilux has a 70-litre capacity; the Ford Supercab’s is 48.5 litres and an Isuzu double cab’s tank 85 litres. So depending on your fuel consumption you can do 300 to 800 km more before filling up, than would otherwise have been possible.

What does it involve?

Important: When taking your vehicle to have such a tank fitted, make sure that there’s very little fuel left in the main tank, as they’ll be drilling a hole in it.

1. Most long-range tanks, especially those on bakkie-based 4x4s, are situated in the cavity above the spare wheel at the back.

2. After removing the spare wheel, two beams or braces are bolted onto the chassis to serve as mounting points for the new tank.


3. The main tank now gets a fuel hose to connect it to the auxiliary tank. To do this, a hole is drilled into the main tank from the outside.


4. From the outside, the connecting hose is pulled in through the hole in the main tank. Two people are needed for this tricky job – one to feed a thin wire with a hook down the vehicle’s filler hole and another who tries to get hold of this wire by inserting his own wire hook through the hole drilled at the back of the fuel tank. When he succeeds, the connecting hose is then pulled through.

4a. 4b.

5. The connecting hose is locked and sealed with a special washer.


6. The filler neck into which you insert the fuel pipe at the garage is removed. In the case of the Frontrunner, they then add an extra “branch” to this filler neck so that both tanks are filled up simultaneously.


7. The second tank’s breather pipe is also connected to the filler neck’s existing breather pipe. The whole filler-neck assembly is then refitted to the vehicle.


8. After all the “plumbing” is finished, the long-range tank is bolted to the mounting beams at the back of the chassis.


9. When everything is finished, the spare tyre is refitted.


Things to keep in mind:

•    Make space!
After fitting a long-range tank, your spare wheel might sit lower than before. This might necessitate mounting the spare wheel on the back of the vehicle if you are concerned about ground clearance.

•    Weight gain.
It might be necessary to upgrade your rear suspension to cope with the weight of the extra fuel tank.

•    Go hard.
Most of the new tanks have had their “teething problems” sorted out. But if you happen to stumble across an older, second-hand tank, make sure there’s absolutely no flex in the sheet metal. If so, the chances of it developing metal fatigue (and a subsequent leak) are good on rough roads. The newer tanks have all been strengthened adequately.

•    Find fault.
Your fuel needle will keep showing “full” until the auxiliary tank is empty. Thereafter it will continue to show you how the main tank’s level decreases. That is if everything has been installed correctly.
Sometimes a mistake during fitment means that you struggle to fill both tanks on a warm day – the rear tank won’t fill up completely; or the fuel needle acts “funny”. Then you have to take your vehicle back to the workshop to fix the problem. So, first experiment at home to see if the system works as it should. The middle of Angola isn’t really the place for system checks.

•    How much?
In the case of a Hilux double cab it will cost about R3 550.
LA Sport charges about R650 to fit it. If you leave your vehicle there in the morning you can pick it up later that same day, provided their workshop isn’t too busy.

Why not simply use jerry cans?

Jerry cans are cheaper and cost between R150 and R300, depending on size and whether it’s plastic or steel. But they do have some disadvantages.

They obviously create a fire hazard in your vehicle and the fuel fumes tend to spoil the pleasure of savouring your favourite frikkadels.

And even if you mount your jerry cans outside the vehicle, you still have to fill up your vehicle with a funnel. It can get messy (I had to get rid of a pair of trousers and shoes after a refilling incident with a jerry can full of diesel) and it’s quite hard work, especially after having to hold up the fourth full 25-litre jerry can while filling up.

Jerry cans on the roof might make you feel like the Camel Man’s lesser-known twin, but it also means more wind resistance – which, in turn, increases your fuel consumption. It also increases your vehicle’s centre of gravity, increasing the risk of a roll-over when your vehicle leans over past a certain gradient

Can I do it myself

If you’re technically quite experienced you would be able to. But you’d have to have the equipment to jack up the vehicle’s rear quite high. And you should know your stuff. Especially when drilling the hole into the main fuel tank and pulling through the connecting fuel hose from the outside. It’s not something you’d want to take on while humming along to Cliff Richard and “winging it”.