Why We Upgraded Our Y62 Patrol to a 4200kg GVM

When you start setting up a Nissan Y62 Patrol for serious touring, the weight adds up surprisingly quickly.

Bullbar, winch, driving lights, roof rack, drawers, fridge, recovery gear, tools, extra water, electrical gear and everything else we carry all contribute to the vehicle's overall weight. Add a caravan onto the back and the tow-ball weight becomes part of the Patrol's payload as well.

For us, upgrading the GVM wasn't about seeing how much gear we could pile into the Patrol. It was about building a touring and towing setup that could legally carry the equipment we actually use while travelling Australia.

Our Y62 Weight Limits

Our Patrol has undergone a 4X4 DNA 4200kg GVM upgrade using an On Track suspension setup.

Our certified limits are:

• GVM: 4200kg
• GCM: 7700kg
• Front Axle: 1750kg
• Rear Axle: 2450kg

Those numbers are important because staying under the 4200kg GVM is only one part of managing the vehicle's weight.

The front and rear axles also have their own individual limits, and when we're towing, the total combination needs to remain within the applicable 7700kg GCM.

What is GVM?

GVM stands for Gross Vehicle Mass — the maximum the vehicle is permitted to weigh when fully loaded.

That includes the vehicle itself, fuel, passengers and everything fitted to or carried by it.

For our Patrol that means things like the bullbar, winch, roof rack, drawers, fridge, tools, recovery gear, water, electrical equipment and all the other gear we carry while travelling.

Importantly for anyone towing a caravan, tow-ball download also contributes to the load carried by the vehicle.

It's easy to see how a touring 4WD can gain hundreds of kilograms before you've even started packing clothes and food.

Why We Went to 4200kg

Our Y62 isn't a lightly modified daily driver. It's been built specifically for touring, towing and exploring.

We carry a fridge, rear drawers, tools, recovery equipment, communications gear, water and a substantial 12V setup. Then there are four of us travelling in the Patrol and the additional load imposed by our caravan.

The standard payload disappears surprisingly quickly once a Y62 is set up this way.

Moving to a 4200kg GVM gives us considerably more usable carrying capacity and allows the suspension and vehicle to be properly set up around the loads we're actually carrying.

The 4X4 DNA / On Track Setup

A proper GVM upgrade is about more than simply fitting a set of heavier springs.

Our upgrade was completed through 4X4 DNA, using an On Track suspension setup designed around the increased carrying capacity of the Patrol.

Spring selection is particularly important.

Our Patrol has permanent accessories adding weight to both ends of the vehicle, so the suspension needs to suit the actual build rather than simply fitting the stiffest possible spring.

We still want the Patrol to work as a 4WD when the caravan is disconnected, and one of the things we've always liked about the Y62 is how comfortable it is to drive.

Increasing its load-carrying ability shouldn't mean throwing all of that away.

Airbag Man Rear Airbags

We also run Airbag Man rear airbags.

These give us additional adjustment at the rear depending on how we're using the Patrol and are particularly useful when transitioning between towing the caravan and running without it.

It's important to understand that airbags don't increase the legal GVM or axle capacities of the vehicle.

Our increased legal carrying capacity comes from the engineered and certified GVM upgrade. The airbags are there to complement the suspension setup and help us manage changing loads.

GVM Isn't the Only Number That Matters

This is probably the biggest thing we've learnt about vehicle weights.

Being under GVM doesn't automatically mean you're legal.

Our Patrol has a maximum front axle load of 1750kg and a rear axle load of 2450kg.

That means we could theoretically weigh less than 4200kg overall but still have too much weight over one axle.

This becomes particularly important when towing because tow-ball download doesn't simply add weight to the Patrol — its position behind the rear axle also changes how the load is distributed across the vehicle.

That's why we look at individual axle weights rather than relying solely on the total number displayed on a weighbridge.

Then There's the 7700kg GCM

Our upgraded setup has a 7700kg Gross Combination Mass.

GCM relates to the combined mass of the vehicle and trailer when they're operating together.

For us, this is particularly important because we're towing a full-size family caravan while carrying four people and touring equipment in the Patrol.

You can't simply look at a 4200kg GVM and the caravan's maximum ATM, add the two figures together and assume you can legally load both to their individual maximums.

The entire combination still needs to work within its applicable limits.

It's a balancing act between vehicle weight, caravan weight, axle loads, ball weight and the total combination.

Understanding the Main Numbers

There are a few figures worth understanding if you're setting up a touring 4WD and caravan.

• GVM – 4200kg: The maximum permitted loaded mass of our Patrol.
• Front Axle – 1750kg: The maximum permitted load over our front axle.
• Rear Axle – 2450kg: The maximum permitted load over our rear axle.
• GCM – 7700kg: The applicable maximum combined mass of our Patrol and caravan combination.
• ATM: The maximum permitted mass of the caravan when it's standing independently and carrying its full load.
• Tow-Ball Download: The load the caravan applies to the tow vehicle through the towball. This needs to be considered as part of the Patrol's loaded weight and axle loading.

Each number tells you something different, and all of them need to be considered together.

Was the GVM Upgrade Worth It?

For the way we've built and use our Patrol, absolutely.

We're travelling full-time, towing our home behind us and carrying the equipment we need to explore once the caravan is unhitched.

The 4200kg GVM upgrade isn't one of the flashy modifications on the Patrol, but it's one of the most important parts of the entire build.

It gives us the capacity we need while allowing the suspension to be set up around the way the vehicle is actually used.

And when you're towing a caravan around Australia, knowing exactly what your vehicle can legally carry is a lot more important than simply hoping you're under the limit.