(Photo: Graeme MacPherson)
Indefinitely Wild

How to Build Your Overland Vehicle Like an Australian

What American off-road enthusiasts can learn from the culture of regulation and responsibility down under


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Like the United States, Australia has a long, adventurous history of off-road exploration. Unlike this country, Australia applies a significant level of regulation to the activity. Rather than discourage participation or limit sales of 4×4’s and their associated parts and accessories, the country’s approach has actually helped make off-road travel an everyday facet of mainstream Australian life, and fostered a culture that prioritizes safety, responsibility, and expertise. 

“In addition to their regulations and general sense of responsibility, it is the remote and hazardous conditions that have spurned many of these pragmatic approaches,” says Scott Brady, the publisher of Overland Journal. “Animal strikes and roll-overs are such a common occurrence in the outback that travelers prioritize safe handling above all else.”

And American drivers can take advantage of that regulation, too. Using aftermarket parts that are made to Australian standards, sticking to the guidelines defined by that country’s regulations, and learning lessons from Aussie off-road culture can help you build a safer, more capable vehicle, and get more out of your time in the bush. Here’s how. 


Lesson One: Run a Sensible Tire Size

The regulations we’re talking about here come in the form of the Australian Design Rules, which create a national standard for vehicle safety, as well as additional requirements imposed by individual states. Some modifications can be performed simply by remaining within certain guidelines, while others require engineering, which is a certification process that validates the total performance and safety of a heavily modified vehicle. 

The maximum tire size you can fit without putting a vehicle through engineering is typically 50 millimeters (or two inches) larger than stock. In some states, tire size is also subject to regulations dictating the total additional height you can add to a vehicle, measured at the roof. Because half a tire’s diameter exists above the axle, fitting a larger tire increases the total height of the vehicle by half the additional tire size. The roof height increase limit then accounts for the total lift created by a larger tire and longer suspension or taller body mounts. 

Most new 4×4’s come with 31-inch tires. So the vast majority of drivers beefing up the off-road capabilities of those vehicles are limited to 33-inch rubber. Drivers hoping to increase their tire size by more than two inches will have to put their vehicle through engineering to ensure that it can still safely perform emergency lane changes and braking maneuvers. 

Odds are, a 33-inch tire is also going to fit into your pickup or SUV’s stock spare location, saving you the hassle, expense, and weight involved in moving that somewhere else.

Your Takeaway: While larger tires look cool and easily roll over large obstacles, a balance must be struck between size and more important factors like safety, fuel economy, and performance. A happy middle ground usually lands at around 33 inches. Essentially every vehicle you see crossing rugged tracks through Australia’s Outback is doing so on 33’s. Fitting larger tires will likely require further, expensive modification like re-gearing, cutting body panels, relocating diffs, and fitting custom driveshafts, CVs, and control arms. And even then, the end result will still massively compromise on-road safety and ease of use, if not the outright reliability and longevity of your rig. 

Visibly sagging in the rear, the springs on this modified Range Rover simply aren’t heavy enough to support the weight it’s carrying. This can impair handling and safety on pavement, but real problems will come off-road, where inadequate spring rates can transfer so many forces to the dampers, that those components quickly overheat. Movement created by off-camber obstacles won’t be adequately controlled, which could increase the odds of a rollover. 

Lesson Two: Fit Suspension Designed to Support Your Vehicle’s Unique Weight

This one doesn’t come from regulation, but rather wisdom hard earned by living on a continent that’s mostly empty space. Where American off-roaders typically resort to extremes—running the cheapest suspension upgrades possible to achieve the most lift or maxing out credit cards on ridiculously expensive setups designed to win races—Australians almost all resort to a practical middle ground: equipping their vehicles with the correct spring rate to support their all-up weight, then dampers that can adequately control how that weight moves as they bounce over endless miles of corrugations. 

Where regulations do enter the picture is on spacers. It’s common to see Americans trying to achieve monster truck dreams on Tonka truck budgets resort to extending the shackles that mount rear leaf springs to the frame. That practice is totally banned in Australia, as it compromises safety by failing to adequately control lateral movements of those spring packs. 

Australia also regulates the outright height added by aftermarket suspension. The amount varies by state but is usually around one or two inches. Additional height may allow fitment of taller tires and better enable a vehicle to clear obstacles, but it also reduces stability, and by pushing the CVs on independent front suspension vehicles too far downwards, it also limits travel and adds stress to those important, fragile parts. 

Your Takeaway: This creates a well-defined set of best practices. First and foremost, springs should be chosen that match the total weight of your vehicle as you load it up for off-road trips. Dampers should be upgraded to control the movements of the vehicle with that weight onboard through punishing terrain. Both should combine to create a total lift of about two inches. This can be achieved expensively, through custom components and custom tuning, or relatively affordably, from Australian brands versed in producing this exact setup. 

Take my two trucks, for example. Both the Ranger and the 200-series Land Cruiser run Old Man Emu BP-51 suspension systems. Before ordering them, I calculated the total weight of all the modifications I was planning, and all the people, gear, and dogs I typically carry. I was then able to select from a variety of different weight springs, while the dampers came valved specifically for the vehicle in question. The systems on both trucks provide two inches of lift—perfect for clearing 33-inch tires. It’s as effective as a custom setup, just much more affordable since it’s mass manufactured.

This Tundra has a payload rating of 1,600 pounds. The wet weight of that camper is 1,712 pounds, before you add the tent. 

Lesson Three: Payload Above All Else

Cops in Australia are trained to spot the signs of an overloaded vehicle, and if they suspect you of driving one, they can pull you over and direct you to a roadside scale. If your total weight exceeds your truck’s gross vehicle weight rating, they can issue you a fix-it ticket or, in extreme cases, impound it on the spot. 

Australians take GVWR (or, as they call it, gross vehicle mass) seriously for a reason. Exceeding the total weight a vehicle is designed to carry causes accidents. It can do that by increasing braking distances, creating brake failures, leading to rollovers, and overtaxing important components. In short, it can kill both you and other road users. 

While American cops aren’t trained to look for overloaded vehicles, physics don’t change when they cross an ocean. And neither do many of the legal concerns. Just like in Australia, exceeding GVWR can invalidate your insurance, push liability in your direction in the event of a crash, and lead to charges of negligence. 

Calculating a vehicle’s payload is easy: it’s simply the GVWR, minus the curb weight, which typically includes a road-ready vehicle full of all fluids, minus gasoline. So anything or anyone you put in the vehicle, or any parts you mount to it, count toward your legal maximum weight. When in doubt, visit a scale and see what your vehicle actually weighs fully loaded down for a camping trip. 

Your Takeaway: This is one area where America handily beats Australia. The most common pickups there are mid-sizes, like the Ford Ranger (Australia’s bestselling vehicle), and the largest noncommercial vehicle you’ll likely see on the road is a 79-series Land Cruiser (max payload under 2,700 pounds). Meanwhile, the bestselling vehicle in America is the Ford F-150, which can be optioned to carry 3,325 pounds. And our trucks get even larger—the Ford Super Duty can haul up to 7,044 pounds. There’s just no excuse here to drive a dangerously overloaded vehicle. Another thing working in our favor? Some of our big trucks also come stock with 35-inch tires. 

All the lights mounted on this Bronco sure look cool, right? The problem is, every single one of them is either a short- or mid-distance light. So while they’re very bright, such a setup risks concentrating all that performance right in front of the truck, which may limit rather than enhance nighttime vision.

Lesson Four: Fit Lights to Add Vision, Not to Look Cool

ADR regulations specify that you can add up to four additional driving lights, but that those lights must switch on and off via the high beam stalk, can’t cause any glare or reflection that may distract the driver, and can’t protrude outside of the vehicle’s silhouette (or that of an aftermarket bumper). Some Australian states won’t let you put driving lights on your roof or A-pillars, basically limiting their location to the front bumper. 

That’s right, lightbars and other crazy powerful aftermarket lights are legal in Australia. If you’re driving across the outback at night, you simply need to be able to see the road or track in front of you with a clarity stock headlamps can’t provide, and the right lights can help you avoid the ever-present kangaroos. 

ADR rules also outlaw the fitment of LED or HID bulbs into halogen reflector headlamps, since they can impair the vision of oncoming drivers, and don’t add any additional performance

That creates a situation entirely opposite to what we have here in the U.S., where aftermarket lights are almost universally illegal, but widely used, and too often misunderstood. Australians rely on their totally legal aftermarket lighting setups for safety, creating a culture where lightmakers compete on performance, not looks, and do so with numbers that according to law must be factual. 

Your Takeaway: Mounting a pair of round driving lights in front of your grille is the most effective way to see further down the road or track at night. That location eliminates any possibility of reflection on the hood and minimizes the tendency of dust and fog to reduce forward visibility. If you run aftermarket driving lights, wiring them up to the high beam stalk (with an additional switch to enable and disable them entirely) will allow you to easily switch them off when other drivers approach. 

When considering the performance of those lights, look for the distance that they can project one lux, which is an effective measurement of their ability to help you see further down the road at night. Lightmakers who quote only the outright brightness of their lights are lying to their customers through omission

Take the above shot of how effective the single pair of Lightforce HTX2’s (all Lightforce lights are made in South Australia) on my Land Cruiser is, clearly illuminating distant objects, and effectively lighting up the track’s periphery without blowing out the foreground, and compare it to this video of a more typically American lighting setup. Note that the lights on that person’s truck may be very bright, but actually create such an overwhelming level of brightness in the foreground that it restricts their ability to see further into the dark. 

The offset of these aftermarket wheels is causing these tires to poke about two inches outside this Bronco’s generous wheel arches. That could ruin that poor truck’s paint, and fling rocks at the windshields of other drivers. More importantly, it could impair the truck’s steering feel and reduce stability under heavy braking.

Lesson Five: Keep Your Tires Inside Your Arches

ADR rules dictate that your tires can’t poke out beyond the edge of your wheel arches. They also ban any and all wheel spacers. Western Australia limits any modifications that may increase your track width to 50 millimeters (two inches), total. 

Seeking snazzy looks and the room to fit large tires, it’s common to see American drivers fit aftermarket wheels with less offset than stock. Offset is the position, inwards or outwards of the wheel rim, relative to the hub. Taller tires also tend to be wider tires, and the cheap way to clear suspension components is to shift the rim those mount to outwards by an inch or two. Because it’s easier and cheaper to produce and stock wheels of a single offset, many wheel makers only produce wheels with high offsets.

While there tends to be some space for increased offset inside most trucks’ wheel arches, that’s usually only about one inch per side. Most aftermarket rims add two inches of offset per side. This can leave an inch or more of tire poking out of the arch, which then throws all sorts of debris at your paint and the windshields of other drivers.

Increasing your track width can also impair handling and braking performance by altering the complex geometry of your front suspension. If you’ve fitted different wheels and tires, and you truck tends to wander, becomes slow to respond to steering inputs, and is unstable while braking, that’s because those wheels have altered your scrub radius. Additional offset is also really hard on your wheel bearings, bringing forward the time when those will require maintenance or fail. 

Your Takeaway: Sticking with the stock wheels (or aftermarket ones of the same dimensions) and tires that fit them, is an easy way to ensure your vehicle’s handling remains safe and maintains the longevity of your wheel bearings. If everyone kept their tires inside their arches, cracked windshields wouldn’t be such a common occurrence in areas with lots of dirt and gravel roads. 

Tucked way up into the void between the 200’s frame rails, this 12.5-gallon auxiliary tank from Long Range America (silver) takes advantage of otherwise unused space to add a significant amount of fuel range. (Photo: Nathan Norby)

Lesson Six: Maximize Your Fuel Range

Australia is slightly larger than the combined area of the lower 48 states, but less than 26 million people live there. That adds up to an awful lot of empty places, and a lot of distance between gas stations. So fuel range is an important calculation for Australian drivers, especially ones who want to explore remote areas. 

There are two factors that influence range: fuel economy and capacity. When we talk about modifications like large tires reducing miles per gallon, our emphasis isn’t necessarily on the environment or your wallet, but on your range. Take the article I wrote about all the improper modifications people like performing to Toyota Tacomas for instance. Fitting 33’s to one of those without regearing can reduce on-road fuel economy to just 12 miles per gallon. Given that off-road terrain will typically drop your economy even further, and that the stock fuel tank only holds 21 gallons, that can result in a fuel range that starts at 250 miles, and falls to 125 or less once you’re wheeling. 

Where American drivers typically only worry about fuel range while planning adventurous camping trips, Australians going about normal business need to worry about it every day. Fuel cans are unregulated in that country, but all their leaks and smells and hassle remain just as annoying, no matter where you are. So it’s common to see Australian drivers fit larger fuel tanks, or even add auxiliary ones. While expensive to buy and install, these fuel tanks make accessing additional fuel easy. Larger tanks work just like standard ones, only carrying more fuel, while auxiliary tanks simply pump their fuel into the stock tank when that runs low. 

Your Takeaway: The cheapest, easiest way to maintain a good fuel range is simply to limit tire size and other modifications that so quickly reduce it. Adding fuel capacity can be cheap by using gas cans, but carrying those safely, and using them regularly becomes a headache. If you want to add significant range without hassles, then installing a larger fuel tank, or an auxiliary one, is an effective, if expensive solution. 

Long Range America imports plus-size and auxiliary fuel tanks from Australia. I installed one of their 12.5-gallon auxiliary tanks on the 200-series. Because it fills otherwise unused space between the rear frame rails, it allows me to keep the spare tire mounted in the stock location, under the truck, while adding 50 percent more capacity. Tanks as large as 40 gallons are available for the Land Cruiser, if you’re willing to relocate that spare tire. You can find similar arrangements for other vehicles. 

ARB performed physical crash tests of its bumpers fitted to vehicles in collaboration with the Australasian New Car Assessment Program. (Photo: ARB)

Lesson Seven: Add Safety, Not Just Protection

One of the big advantages of Australian regulation is that it doesn’t just apply to individuals performing modifications, but also to the companies that make accessories. Case in point: aftermarket bumpers. 

Here in the States, no regulation is applied to those parts whatsoever. That means off-road bumpers made in the U.S. are as simple as they look: steel plates and hoops welded together, then bolted to the frame. No crash testing is performed, and any compatibility with important safety features like airbag sensors is incidental, at best. 

In Australia, the government dictates that such bumpers be designed and tested to ensure not only total airbag and crumple zone compliance, but that the bumpers actually work to reduce the forces transmitted to the vehicle in an impact. In short: you know the bumper you’re buying will not only work as advertised during an animal strike, but that it will work with the vehicle it’s mounted on to keep you safe in a high speed traffic collision too. 

Similar requirements apply to other protection parts like rock sliders and skid plates, which must be designed so they don’t interfere with side curtain airbags or transmit undue forces to vehicle occupants in a side impact from another vehicle. 

The tests ensure that ARB bumpers will not impair the function of a vehicle’s crumple zones and airbag sensors. As validated in these expensive tests, an ARB bumper will in no way reduce the safety of the vehicle it’s fitted to. (Photo: ARB)

Your Takeaway: While the kind of low-speed, highly-technical rock crawling that’s essentially unique to America might dictate vehicle protection parts that don’t need to perform in on-road accidents, drivers who use their 4×4’s for a mix of on- and off-road travel will definitely benefit from bumpers and sliders that retain compatibility with airbags and crumple zones. The most dangerous part of any journey is likely going to come on the highway, not the trail. Australia’s standards are good enough that simply buying these parts from an Australian company should guarantee they’ll be safe. 

There’s a reason both of my trucks (and the old 4Runner I just sold to a friend) are fitted with ARB Summit bumpers. While traveling in Australia a few years ago, I hit a very large red kangaroo at about 85 miles per hour. Both the vehicle, and the ‘roo survived the collision intact thanks to that bumper. Back home in Montana, where 15 percent of all road fatalities are caused by animal strikes, I trust ARB bumpers with my life, and those of my friends and family.

Lead Photo: Graeme MacPherson