LEXUS GX550 (2024 – PRESENT)

81 LITRE AUXILIARY LONG RANGE FUEL TANK

Brown Davis Releases New 81-Litre Long Range Auxiliary Fuel Tank for the Lexus GX550

Brown Davis has officially launched its brand-new 81-litre long range auxiliary fuel tank for the all-new Lexus GX550, delivering a massive upgrade for owners who demand serious touring and towing capability. When combined with the vehicle’s standard 80-litre main tank, the GX550’s total fuel capacity skyrockets to an impressive 161 litres—more than double the factory capacity.

For long-distance travellers, off-road tourers, and anyone towing heavy trailers, this is a game-changing improvement. The extended range means fewer fuel stops, increased flexibility in remote areas, and the peace of mind that comes with carrying significantly more fuel onboard.

Clever Engineering and Complete Hardware Integration

To accommodate the 81-litre tank, Brown Davis includes a new exhaust section, designed to provide the necessary clearance under the vehicle while maintaining OEM-level fit and durability. All required hardware is supplied, ensuring a clean and straightforward installation.

Fuel transfer is just as easy. With a simple press of a button, the auxiliary tank’s electric transfer pump sends fuel directly into the main tank. Everything needed—pump, wiring, switch, hoses, and fittings—is included in the kit.

For seamless refuelling, Brown Davis integrates a T-piece filler system, which fills both the main tank and auxiliary tank simultaneously from the standard filler point.

 

Specifications

PART NUMBER: LGX550A1

TANK TYPE: AUXILIARY

CAPACITY: 81 LITRE

FILLER POINT: STANDARD LOCATION – T PIECE INTO AUXILIARY TANK

FUEL SUPPLY METHOD: TRANSFERS TO MAIN TANK

TANK LOCATION: DOWN PASSENGER SIDE

FITTING TIME: 6 hour/s

MODIFICATIONS: NEW CENTER SECTION OF EXHUAST SUPPLIED

Photos of Fitted Tank

Key Features

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Tapered approach angle to reduce chance of impact and maintain factory clearance

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Internal baffling system to prevent fuel slosh and strengthen tank structure

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Gusseted brackets with double thickness pads to spread tank mounting loads

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Fuel pump sender flange

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Fast fill breather for rapid filling and to reduce bowser shut off

Fuel Feed System

FUEL TRANSFER SYSTEM

This system is designed to pump the fuel from the Brown Davis auxiliary fuel tank into the vehicles standard fuel tank. At the flick of a switch fuel will be pumped into your vehicles standard tank to then be feed to the engine. An LED gauge is supplied to show driver the fuel level of the auxiliary fuel tank at all times. When the auxiliary tank becomes empty an automatic alarm will sound to tell driver to switch pump system off. This prevents pump from continuously running which can course pump failure. All parts and hardware for install are supplied

Fuel pumps burning out is now a thing of the past. Brown Davis has developed a new auxiliary fuel tank gauge, switch and buzzer unit to be supplied with most Brown Davis auxiliary transfer fuel tanks. the small unit is no bigger then a 10 cent coin and can be mounted nicely in vehicles dashes.

TANK FULL

FUEL NOT TRANSFERRING

The LED Gauge will show the auxiliary tank’s fuel level at all times, even when the pump is not running.

TANK FULL

FUEL TRANSFERRING

When the button is pressed, the fuel pump will commence transferring fuel from the auxiliary fuel tank to your vehicles main fuel tank. The round yellow LED light indicates that the pump is running.

TANK HALF FULL

FUEL TRANSFERRING

As fuel is being transferred from the auxiliary to the main fuel tank, the LED light will indicate the fuel level remaining within the Brown Davis auxiliary fuel tank. At any stage, the fuel pump activator button on the gauge can be pressed to stop the transfer of fuel.

TANK EMPTY

FUEL TRANSFERRING

When the auxiliary fuel tank is empty, a buzzer will sound prompting the driver to turn the fuel pump off. This is designed to prevent the fuel pump from any damage and increase its longevity.

Fuel Capacity and Driving Range Comparison

Figures based on GX550 (as quoted by Lexus)
Fuel Consumption (12.3L/100km)Percentage Increase
Brown Davis Long Range Fuel Tank
80 Litre Standard Tank650km–
161L Total – 81 Litre Brown Davis Aux Tank + 80 Litre standard tank1309km101%

101% INCREASE!

Whilst every effort has been made to ensure these figures are accurate vehicles may vary. Vehicles should never be pushed to the point of running out of fuel as it may harm your vehicles engine.

Compatibility

Confirmed fitment

  • Models

    2024 – Lexus GX550

    2025 – Lexus GX550

International vehicles

  • Confirmed fitment

    Confident fitment with world spec vehicles

Optional Upgrades

  • TWIN FILLER NECK

    Comes standard with all new orders. Optional twin filler neck upgrade for those with Brown Davis Auxiliary Tanks installed. Enables the use of high flow diesel pumps and allows user to choose whether to fill both tanks or just fill the main tank, leaving the rear empty until needed.

Aftermarket Accessories

  • Suspension

    Confident fitment with all suspension lifts, GVM upgrades and air-bag kits

  • Rear Bars

    Fitment not yet confirmed with Cruiser Company rear bar. Please contact us to enquire.

Step by Step DIY Instructions

The Brown Davis Lexus GX550 (2024 – Present) tank comes with step by step instructions that walk you through every step of the install.

Warranty and Support

For total peace of mind Brown Davis offers a 3 year warranty on all its fuel tanks. With an Australia wide network built over the 40+ years in the industry, you can go away on your longest journey knowing you will have full support with any issues.

Why Brown Davis

Looking to tackle the toughest off-road adventures without worrying about running out of fuel? Brown Davis’ Long-Range Fuel Tanks are the ultimate solution. Built tough, these tanks are designed to extend your range, ensuring you can go further, explore deeper, and push boundaries without the constant need to refuel or carry those pesky jerry cans. Whether you’re navigating rugged tracks or embarking on an epic tour of Australia, trust Brown Davis to keep you powered up every step of the way. Engineered for durability and reliability, our tanks are the perfect upgrade for the serious adventurer. Ready to go further?

Watch Jase from All4Adventure show the benefits of a Brown Davis Long Range Fuel Tank!

Brown Davis manufactures a wide range of both Steel and Poly tanks so finding the right type of tank for your vehicle is crucial. Many factors need to taken into account so below are the highlights of both our steel and poly long range fuel tanks.

STEEL LONG RANGE FUEL TANKS

  • DRAIN PLUG

    ALL BROWN DAVIS STEEL FUEL TANKS COME WITH A DRAIN PLUG FOR DRAINING CONTAMINATED FUEL OR EVEN COLLECTING SOME FUEL FOR A MATE.

  • BAFFLES

    ALL BROWN DAVIS STEEL LONG RANGE FUEL TANKS HAVE INTERNAL BAFFFLES, THIS MINIMIZES FUEL SLOSH AND MOVEMENT. ALSO PROVIDING THE TANK WITH GREATER STRENGTH AND INGEGRITY.

  • SWIRL POT

    ALMOST ALL BROWN DAVIS STEEL LONG RANGE FUEL TANKS HAVE AN INTERNAL SWIRL POT. THIS DESIGN TRAPS FUEL AROUND THE PICK UP SO THAT YOU CAN RUN DOWN TO THE LAST FEW LITRES.

For 4WDs and tourers planning to head off the beaten track, our aluminized steel Long Range Fuel Tank is the best option. 

POLY LONG RANGE FUEL TANKS

  • LIGHT WEIGHT

    IF WEIGHT IS CRITICAL IN YOUR VEHICLE ON AVERAGE MOST LONG RANGE POLY TANKS ARE 10-15KG LIGHTER THAN STEEL TANKS.

For fleet managers and customers sitting primarily on surfaced road, poly long range fuel tanks is a great option.

Justin from Patriot compares steel and poly Long Range Fuel Tanks

Building a Brown Davis Tank

Since the beginning, Brown Davis has taken pride in the construction of our tanks, our INEOS Grenadier (2023-Present) tank is no exception. Our tanks are made with quality and care, from the materials we use to the stringent pressure testing, they are prepared for the harshest conditions.

Laser Cut Aluminized Steel

Manufacturing our steel tanks starts with laser cut aluminized steel. With this material, your tank will have the strength and durability of steel, and the anti-corrosive properties of aluminum to make sure their is no rust.

Folded Before Welded

Before welding the tank, we use specialized machinery to fold the laser cut aluminized steel to decrease the amount of time and labor put into welding. Folded parts also have superior strength to welded parts.

High Quality Welding Every Time

Next, our experienced welders add the brackets, swirl pot and baffles to the tank and then weld it all off.  We use jigs to locate the brackets for each individual tank so installation is as consistent and easy as possible for every vehicle.

Pressure Testing

Lastly, we take it through an air pressure test. This involves a soap test, submersion test and a pressure gauge. These techniques help us identify any rare leaks and where they’re coming from. If air isn’t coming out, fuel definitely isn’t.

Building a tank- A walk through with Matt from The Explore Life

Frequently Asked Questions

Yes. All Brown Davis Fuel Tanks come with everything required to be fitted to your vehicle. This includes auxiliary (secondary) Fuel Tanks which come with electric fuel pump, hoses, wiring and fuel gauge.

After the installation of any Long Range Fuel Tank the vehicles fuel gauge (needle fuel gauge) will change slightly. This will be different in each vehicle depending on the tank shape. Some tanks will remain on full for a few hundred kilometres due to the extra height in the new tank. In most of the more popular tanks, we supply a special float arm to go with our tank, this gives a more accurate reading for the gauge. What we do make sure of is that the vehicles low fuel light and empty point is accurate on all tanks. This of course is the point on the gauge you want absolutely correct.

In short, the distance to empty function on your trip computer won’t remain accurate with your new Long-Range Tank. This is because the vehicles ECU (Engine Control Unit) has the volume of the original tank size programmed within it. However, with many of our Long-Range Replacement Fuel Tanks being approximately double the volume of the original fuel tank, you can simply double the ‘distance to empty’ reading to roughly estimate your new driving range.

For certain makes and models there are unaffiliated 3rd party software programs that can re-write information to your ECU, for example, there are options for the Ford Ranger. We believe this fix is ultimately unnecessary, however, if you wish to have your ‘distance to empty’ read true for the new fuel volume, we recommend researching if there are options available for your vehicle. 

Good news is, your fuel gauge will remain accurate, as the float inside the tank will indicate how much fuel is inside the tank, so your readings going from Full, to ¾ to ½ right down to empty will remain accurate. Furthermore, your low fuel warning light will work as intended.

We recommend to zero your odometer when you refuel and check your fuel consumption. Over time you’ll be able to establish how far you can travel in different driving conditions, i.e. towing, sand, dirt, etc. 

If you are planning to go off-road, we recommend our Steel Long Range Fuel Tanks where extra protection is not necessary. Made from 2mm Aluminised Steel, strength and durability are without question. Need more convincing? Check out the boys from All4Adventure and ExploreLife, both who run our steel tanks and have seen their fair share of remote and rugged environments.

Our Long Range Replacement Fuel Tanks are designed to make no impact to your vehicle’s stock clearance and ramp over angle. We design our Fuel Tanks with not only touring but hard four-wheel-driving in mind, therefore, maintaining stock clearance is paramount. 

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