How to Calculate Your Towing Capacity in NZ (2025 Guide)

Planning to tow a trailer, caravan, or boat? Understanding your vehicle’s towing capacity is essential — not just for safety but also for insurance and legal compliance in New Zealand.

At Dave Allen Motors, we’re here to help you calculate towing limits properly before you hit the road.

🔴 What is Towing Capacity?

Towing capacity is the maximum weight your vehicle can legally and safely tow.
It depends on your vehicle’s Gross Vehicle Mass (GVM), Gross Trailer Mass (GTM), and Gross Combined Mass (GCM).

🔴 Key Terms You Must Know:

🔴 How to Calculate Towing Capacity

Step 1: Find your vehicle’s GCM (often listed in the handbook or VIN plate).
Step 2: Subtract your fully loaded GVM (car + fuel, passengers, accessories).
Step 3: What’s left = the maximum trailer weight you can tow.

Example:

• Toyota HiLux GCM = 5,650kg

• HiLux GVM = 3,000kg

• 5,650kg – 3,000kg = 2,650kg trailer towing capacity

🔴 Factors That Affect Your Real-World Towing Capacity

• 🔧 Weight of accessories (bull bars, roof racks, canopies)

• 🔧 Extra load from passengers, luggage, tools

• 🔧 Fuel load (a full tank adds significant weight)

• 🔧 Tow ball weight (added to your vehicle’s weight)

🔴 Legal & Safety Requirements in NZ

• 📜 Anything towed over 750kg requires electric trailer brakes

• 🚦 GVM must be under 4,500kg to drive on a standard car licence

• 🔒 Never exceed the rating of your tow bar or coupling

• ❗ No passengers allowed in a caravan while towing

🔴 Common Mistakes to Avoid

• ❌ Trusting “paper specs” without checking real-world weights

• ❌ Forgetting to weigh added accessories and passengers

• ❌ Ignoring tow ball load limits (important for stability)

• ❌ Assuming all trailer types are treated equally under the law

🔴 Quick Towing Calculator Table

🔎 Tip: Always weigh your actual setup before towing — don’t guess!

🛡 Why Trust Dave Allen Motors?

• Expert advice on towing vehicles

• Over 200 vehicles in stock — SUVs, 4WDs, ready to tow

• Finance options for your used towing vehicles

• MTA Assured and trusted by Hamilton locals for over 30 years

📍 Ready to Find the Perfect Tow Vehicle?

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