How to calculate your towing capacity

Sophie Hodges
Sophie Hodges
How to calculate your towing capacity

With summer well and truly here, there’s no better time to dust off your caravan, boat or camping trailer and hit the road. But before you do, it’s essential to know your vehicle’s towing capacity for both safety and legal reasons. Towing capacity is not a one-size-fits-all metric, and it’s important to consider the various factors that can affect how much weight your vehicle can haul. As responsible drivers, it falls on us to understand the limitations of our vehicles, safeguarding ourselves and others when out on the open road.

Understanding towing capacity

Towing capacity can be described as the maximum weight a vehicle can tow without compromising performance or safety. There are many components within a vehicle that contribute to its towing capacity; most notably the engine, which produces power, and the transmission, which directs this power to the wheels. The suspension system and brakes contribute to stability and control (crucial for towing heavy loads), and a robust frame ensures structural integrity, even under immense stress.

Some of our favourite vehicles for towing include the Toyota Landcruiser, Nissan Patrol, and Ford Ranger. With plenty of capable options to choose from, we suggest doing your research to find a vehicle that best aligns with your specific needs and budget.

Determining your vehicle’s towing capacity

Understanding your vehicle’s towing capacity is essential for anyone planning on hauling caravans, boats or trailers safely. Primarily, this information can be found in your vehicle’s owner’s manual, where detailed specifications, including towing capacity, are outlined. The owner’s manual also provides insights into critical factors such as engine power, transmission capabilities, suspension systems, and chassis strength, all tailored to the specific make and model of your car. Locating your car’s vehicle identification number (VIN) is also beneficial as this can be used to gain further insights into your vehicle’s factory specifications that influence towing capacity.

  • In Australia the legal unbraked towing capacity of a vehicle is 750kg - this applies to trailers that do not have their own independent braking system.
  • The maximum braked towing capacity in Australia is 3500kg - applying to trailers that do have brakes and are therefore better equipped to handle heavier loads.

Understanding weight

Understanding the weight of what you’re towing is essential when calculating your towing capacity. The Gross Trailer Weight (GTW) represents the total weight of your trailer and its contents. The Gross Combination Mass (GCM) is the maximum weight of your vehicle and trailer combined. Understanding these factors is vital to ensure that you stay within the prescribed towing limits of your vehicle.

It’s also important to remember that not all trailers are built equal. Camper trailers, boat trailers and utility trailers (amongst others) all have unique weight distributions and handling characteristics. Familiarising yourself with what you’re towing enables you to tailor your approach based on the specific demands of your cargo, ultimately ensuring a smoother and more secure towing experience.

Tow vehicle modifications

Vehicle modifications are a popular way to enhance your vehicle’s towing capabilities. One such modification is boosting your engine’s performance to improve towing efficiency. This is useful as a more robust engine can provide increased torque and horsepower, translating to improved towing capabilities. Alternatively, aftermarket towing packages provide solutions such as improved cooling systems, reinforced frames, and enhanced transmission components that bolster a vehicle’s towing capacity. Whilst it might be tempting to purchase all the upgrades, it’s crucial to approach modifications carefully, considering the manufacturer’s guidelines and ensuring that any changes align with safety and legal requirements.

Safe towing capacity

In order to prevent pushing your vehicle to its absolute limits and causing preventable damage, we suggest considering the following:

  • Gross Vehicle Mass (GVM): this refers to the maximum load your vehicle can carry as specified by the manufacturer (including the weight of passengers and aftermarket accessories!). Typically found on the vehicle’s weight placard (located in the driver’s door opening), exceeding this limit puts strain on your suspension, transmission and engine, and can cause expensive damage if ignored.
  • Safety margins: margins are useful as they act as a buffer, accounting for unexpected variables like inclines, adverse weather conditions, or sudden manoeuvres.
  • Towbar rating: this is the maximum weight rating of your towbar and must be adhered to even if the towing capacity of your vehicle is larger.

By calculating towing capacity with these factors in mind, you create a comprehensive picture of your vehicle’s capabilities, ensuring that your towing activities not only comply with guidelines but prioritise safety for you and other road users.

Additional considerations

  • Trailer hitch classifications: Choosing the correct hitch for your vehicle and trailer is vital to ensuring a secure connection. Consider the weight and application of what you’re towing to make an informed decision.
  • Weight distribution systems: When dealing with heavier loads, weight distribution systems help balance the weight between the tow and the trailer, enhancing stability and control.
  • Trailer sway control: Incorporating proactive or reactive trailer sway control mechanisms mitigates the risk of your trailer swinging out of control. These can be mechanical or electric and help to enhance the stability and safety of towing setups.

Common mistakes to avoid

In order to avoid creating a potentially hazardous situation or damaging your set up, we recommend avoiding these common mistakes:

  • Overestimating your towing capacity: ensure your towing endeavours align with your vehicle's true capacity.
  • Neglecting safety recommendations: guidelines for weight distribution, hitch selection and speed limits are designed to optimise towing safety - don’t ignore them!
  • Disregarding maintenance: failure to maintain your trailer can result in issues with brakes, tires or suspension components that can compromise your vehicle's ability to tow safely - not worth the risk in our opinion.
  • Ignoring professional advice: this one’s self explanatory, don’t go rogue in modifying your vehicle - we’re not on the set of Mad Max.

Tips for safe towing

To stay safe, secure and stress-free on the road this season:

  • Drive at a speed which feels safe: this might be under the speed limit and that’s ok!
  • Distribute weight properly: balance is key.
  • Conduct a thorough pre-trip inspection: check your tire pressure, lights, hitch and safety chains.
  • Use your mirrors: visibility is awesome.
  • Keep it smooth: avoid stopping suddenly or steering erratically, emergency braking isn’t always an option.
  • Check the weather app: exercise additional caution and maintain a safe following distance in bad weather.

Empower yourself to make informed decisions the next time you need to tow something by carefully considering your vehicle's capabilities and not overlooking the legal limits. Consider incorporating safety mechanisms and adopting a mindset of caution every time you hit the road. And remember, regardless of whether you’re taking the trailer out for the 1st time or the 100th time, it’s never too late to form some good towing habits.

Going away? Click here to check out our ultimate summer road trip guide!

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