A caravan that sits wider than your 4WD, ute or SUV can quickly turn a routine lane change into guesswork. That is where towing mirror requirements matter. If your standard side mirrors only show the side of the trailer, rather than the lanes and traffic behind it, you need a better view before heading out.
For Perth drivers towing campers, caravans, horse floats, work trailers or boats, extension mirrors are a simple safety upgrade with a real legal purpose. The right pair helps you see approaching vehicles, check your trailer’s position and reverse with more confidence. The wrong pair can vibrate, come loose or extend farther than permitted.
Towing mirror requirements in Western Australia
The practical rule is straightforward: when you are towing, you must be able to see clearly to the rear and along both sides of your vehicle and trailer. Your mirrors need to provide a proper rearward view, not just a glimpse of the trailer’s front corner or side wall.
Standard factory mirrors may be enough when towing a narrow box trailer, small garden trailer or another load that does not block your normal view. However, if the trailer is wider than the towing vehicle, or its body prevents you from seeing the lanes beside and behind it, extension towing mirrors are generally needed.
In Western Australia, towing mirrors must also be securely fitted and safe. They should not have sharp edges, interfere with the safe operation of the vehicle or create an unnecessary hazard for other road users. As a commonly applied Australian measurement, mirrors should not protrude more than 230 mm beyond the widest part of the vehicle or trailer, whichever is wider. Because vehicle rules can change and conditions differ between states, check current WA requirements before a long trip, particularly if you are travelling interstate.
The key point is that extra mirrors are not only for large caravans. A trailer can be only slightly wider than your vehicle and still remove enough side vision to make merging, overtaking and reversing unsafe.
A reversing camera does not replace clear mirror vision
A reversing camera is a handy addition, especially for lining up a hitch, watching a boat trailer at the ramp or backing into a campsite. It does not give the same continuous view down both sides of a caravan while you are travelling at highway speed.
Use cameras, blind-spot monitoring and towing mirrors together where possible. Cameras can have blind areas, become dirty on gravel roads or struggle in glare. Your mirrors remain the fast, always-available way to scan traffic before changing lanes or turning.
When do you need extension towing mirrors?
A quick test in the driveway can tell you a lot. Sit in the normal driving position, adjust your factory side mirrors, then look along each side of the trailer. If you cannot see past the trailer’s widest point to the lane behind, it is time to fit extensions.
You should also consider them if you are towing a load that is close to your vehicle width but long enough to create substantial blind spots. A long camper trailer can hide traffic differently from a short box trailer, even if it is not dramatically wider.
Mirrors are particularly worthwhile for:
- caravans and large camper trailers
- horse floats and enclosed cargo trailers
- wide boat trailers, especially with guides or equipment extending outwards
- trade trailers carrying enclosed tools or materials
- trailers used regularly on freeways, country highways and busy Perth roads
Choosing the right towing mirror setup
There is no single best towing mirror for every vehicle. The right choice depends on your vehicle’s factory mirror shape, the trailer width, how often you tow and whether you spend time on rough roads.
Clip-on or strap-mounted mirrors are popular because they are affordable and easy to remove. They suit occasional towing and can work well when fitted correctly. Their trade-off is that cheaper designs may move in wind, shake on corrugations or rub against the factory mirror housing if they are not properly padded and secured.
Slide-on mirrors are made to fit over specific factory mirror housings. When they are matched to the vehicle, they usually feel more secure and look neater than universal options. They can be a strong choice for regular caravan towing, but compatibility matters. A set designed for one model of Ranger, LandCruiser, Prado or BT-50 may not fit another model year or mirror style.
Permanent replacement towing mirrors are often preferred by people who tow frequently for work or touring. They can provide a broad, stable view and may include powered adjustment, indicators, heating or puddle lights, depending on the vehicle and mirror specification. The downside is a higher upfront cost and the need for correct installation, especially where electrical functions are involved.
A good mirror should give a wide, stable image without blocking your standard mirror completely. It should stay secure at freeway speeds, fold or remove as appropriate when not towing, and suit the way you use the vehicle. For a weekend camper, removable mirrors may make sense. For a ute that tows a work trailer most days, a more permanent solution can be better value over time.
How to set towing mirrors correctly
Even quality extension mirrors will not help much if they are poorly adjusted. Set them up with the trailer hitched on level ground, ideally before you leave home rather than at the first servo stop.
Start by adjusting your factory mirrors as normal. You should see a small amount of your vehicle’s side in the inner edge of each mirror, with most of the view showing the road behind and beside you. Then adjust the towing mirror so it looks past the trailer’s outer edge and covers the next lane. The aim is to minimise the blind area between your normal mirror and the extension.
From the driver’s seat, check that you can see vehicles approaching from behind, moving alongside the trailer and travelling in the adjacent lane. On a caravan, it is useful to see the rear wheels as well, particularly when negotiating tight fuel stops, roundabouts and campsite turns. Do not angle the extension mirror so far down that it only shows the trailer wheels. That view is useful for reversing, but it should not come at the expense of traffic visibility.
After the first 10 to 15 minutes of driving, pull over safely and inspect both mirrors. Look for vibration, slipping straps, contact with the window when folding mirrors, and any movement caused by wind. Repeat this check after rough-road travel. A mirror that was fine around Bayswater may need attention after a long corrugated track.
Common mistakes that reduce visibility
The most common issue is buying a universal mirror because it is cheap, then discovering it does not suit the factory housing. If the clamps sit unevenly or the straps cannot be tensioned properly, the mirror may shake so much that the image is unusable.
Another mistake is leaving extension mirrors fitted when they are no longer needed. Apart from the extra width, they are more exposed to damage in car parks, narrow tracks and drive-throughs. Remove or fold them away when practical, provided your vehicle is fitted with a suitable removable design.
Do not overlook the basics either. Dirty glass, cracked mirror surfaces and loose mounting hardware make a good setup ineffective. Before a towing trip, clean every mirror, check the mounting points and make sure trailer lights, number plate and indicators are not obscured by the mirror arms or straps.
Finally, do not rely on mirrors to compensate for an overloaded or unstable trailer. Correct towball weight, tyre pressures, load distribution, towing capacity and properly working trailer brakes all affect how safely your rig behaves. Mirrors improve your awareness, but they cannot fix poor trailer setup.
Get the fitment right for your vehicle and trailer
Towing mirror requirements are about more than ticking off a rule. They are about reducing stress when a road train passes on Great Northern Highway, when traffic closes in on the freeway, or when you need to manoeuvre a caravan into a tight site before dark.
A properly matched set of towing mirrors gives you a clearer view without adding unnecessary width or hassle. If you are unsure which style suits your 4WD, ute, SUV, van or truck, the team at PHC 4x4 in Bayswater can help match a practical option to your vehicle and the trailer you tow. A few minutes spent checking fitment and adjustment before the trip can make every kilometre feel more controlled.