Just because your 4WD’s brochure says it can tow 3.5 tonnes doesn’t mean it’s safe—or legal. Accessories, passengers, and especially tow ball weight eat into your vehicle’s payload and can easily push you over the gross vehicle mass (GVM) or gross combined mass (GCM) limits. More than half of the vehicles checked by Weigh My Ride in Victoria are overweight. Before towing a caravan, horse float, or trailer, get your setup professionally weighed to avoid fines, mechanical issues, or insurance nightmares.
For the purpose of this article, “Trailer” refers to a caravan, horse float, or any other trailer.
The Big Myth: “My 4WD Can Tow 3.5T”
If you own a modern 4WD—think Toyota LandCruiser, Ford Ranger, Isuzu D-MAX, or Nissan Patrol—you’ve probably seen the proud “3,500 kg towing capacity” splashed across ads and brochures.
Here’s the catch: in real-world conditions, very few setups can actually tow that weight without breaking road rules.
In fact, over 50% of vehicles weighed in Victoria are overweight when paired with a caravan, horse float, or work trailer. That’s not just unsafe—it’s illegal.
Understanding the Weight Jargon
Let’s break down the key terms every Melbourne 4WD owner should know:
- Gross Vehicle Mass (GVM): The maximum your 4WD can legally weigh when fully loaded—fuel, passengers, accessories, and tow ball weight included.
- Gross Combined Mass (GCM): The maximum allowed weight of your tow vehicle and trailer combined.
- Payload: How much weight you can add to the tow vehicle (people, gear, accessories). Typically between 600–700 kg in 4WDs rated to tow 3.5-tonne.
- Tow Ball Mass (TBM): The portion of your trailer’s weight pressing down on the tow ball—usually 8–15% of the trailer’s loaded weight. I.e. a 3-tonne trailer is likely to consume approximately 300kgs of your 4WD’s payload.
Why Most 4WDs Go Overweight
Let’s say you’re towing a 3-tonne caravan with a 300 kg tow ball weight:
- Straight away, that 300 kg eats up almost half your payload.
- Add a bull bar (60–80 kg), roof rack (30–50 kg), drawer system (80–120 kg), and recovery gear (50+ kg).
- Then throw in passengers (say, 80 kg per adult) and your camping gear.
By the time you roll out of your Melbourne driveway bound for Gippsland or the Murray River, you’ve likely blown past your GVM—or worse, your GCM.
Why a Professional Weigh Is a Game-Changer
A weigh service like Weigh My Ride’s commercial and consumer mobile weighing services (based in the Yarra Valley and servicing all of Victoria) goes beyond just checking your trailer’s total weight. Their service includes:
- Individual wheel and axle loads to see if weight is balanced.
- Tow ball mass relative to trailer weight.
- Suspension heights and ride height/angle
- Load distribution and balance
- Safety and suitability check of tow hitch and coupling
- Payload distribution—whether you’re safe and compliant.
You’ll walk away with a detailed report plus recommendations to keep your setup legal and safe for Melbourne highways, regional roads, and off-road trips.
Final Word
Melbourne and regional Victoria are made for 4WDing, camping, and caravanning—but too many drivers are unknowingly illegal when they hitch up. Your 4WD might say “3.5-tonne towing capacity” on paper, but in practice, if towing a 3-tonne+ caravan with a tow vehicle that includes accessories, multiple passengers, and a ~300 kg tow ball mass, then you could be exceeding those limits.
Before your next trip, get your setup professionally weighed. It’s the best way to protect your passengers, your vehicle, and your wallet.
