Article from 4WDing Australia.
I’m very curious to know how many of you know what your 4WD weighs with no gear in it, and when it is loaded up for a trip away. In Australia, all 4WD’s come out with a GVM, Pay load, GCM and Towing Capacity. If you exceed these, you risk damaging your vehicle, having an accident and voiding your 4WD insurance.
It is super easy to have a 4WD that is over weight. How do I know? Check out what our Dmax weighed in at, and what we had to do about it; Isuzu Dmax touring build; a look at what it weighs.
Weight is more important than you might realise, and forms one of 32 ways to make your 4WD illegal.
So, how many of you know what your GVM and payload is? I’ve spent a bit of time looking into this, and have been very surprised with the results.
What do these acronyms mean?
GVM stands for Gross Vehicle Mass, and refers to the maximum weight your vehicle can be at any given time. It is the combination of your Tare Mass and Pay load
Your pay load is the amount of weight you can add to a standard vehicle before it becomes illegal. Anything that is necessary for the operation of the vehicle is part of the tare mass, and anything above this is part of your pay load.
This includes the weight of your passengers, the tow ball weight of a trailer (if you are towing) and all of your accessories and luggage. This is a very important piece of knowledge for those who own a 4WD.
Tare weight refers to the unladen weight of your vehicle, with only parts that are necessary for operation of the vehicle. It does not include any aftermarket accessories
GCM stands for Gross Combination Mass, and is the maximum weight your vehicle and what you are towing can be. Generally this is in between 3 – 6 tonnes for a 4WD.
Every vehicle comes with a set towing capacity. Anything you tow must be under this weight. Be sure you factor into account whether the trailer has brakes or not!
Lets make it clearer
So, the above can be a bit tricky to get your head around, so lets look at our 80 Series Land Cruiser for example. You can get these figures from http://www.redbook.com.au for your own vehicle (just find the right model; its easy as).
Gross Vehicle Mass (GVM): 2960kg
Gross Combination Mass (GCM): 5460kg
Pay Load: 865kg
Towing Capacity (braked): 2500kg
If you take the Pay load (865kg) from the GVM (2960kg) you are left with 2095kg. This means the 80 Series Land Cruiser when empty weighs 2095kg, and you can add 865kg of weight to the 4WD. Everything that adds weight comes from the 865kg, including passengers, fuel, water, accessories and also very importantly, the tow ball weight applied when you are towing a trailer.
If you are towing, you must be under the GCM (5460kg), as well as the GVM.
If you want a clear guide to stay legal, check this out – Towing capacity; a simple guide to keep you legal.
The average 4WD
Let’s take a fairly average 4WD, with 2 adults, 2 kids, a few modifications and gear required to go on a 1 – 2 week camping trip. We will add everything up that contributes to the GVM, and see what the final weight is. For more information, check out our weight page at 4WD Weights.
- Steel Bull Bar (40kg)
- UHF Radio, antenna and spotlights (5kg)
- Second Battery (20kg)
- Winch with dynema rope (much lighter than steel cable) (35kg)
- Sidesteps (30kg)
- Roof Rack full length aluminium (25kg)
- Cargo Barrier (10kg)
- Rear Drawer System (50kg)
- 60L fridge with food (70kg)
- 80L water (90kg)
- Long range fuel tank with fuel (150kg)
- Clothes for 4 (40kg)
- Spare parts and tools (30kg )
- Cooking equipment (20kg)
- Tent (20kg)
- Camping chairs (20kg)
- 2 adults and 2 children (220kg)
- Portable electronics (Camera’s, tablets, DVD players, phones etc) (10kg)
Add just the above up, and you are looking at 885kg. That’s not to mention the many other common accessories and other gear regularly found in a 4WD; rear bar, second spare, generator, Maxtrax, fishing gear, upgraded suspension, larger tyres, firewood, solar panels, scrub bars, work lights, LPG bottles, ratchet straps etc!
If you are towing a trailer, the tow ball weight is deducted from your payload. The average trailer would have a tow ball weight of 50 – 300kg. Most 4WD wagons have a payload of in between 500 and 800kg, and Utes are up around 800 – 1200kg. This means that many would be cutting it very close, or be well over the maximum GVM. If you are considering one or the other, check out 4WD Ute or Wagon; which one’s best?
I will quickly mention that every vehicle also has individual axle ratings. This is to ensure that when you load your 4WD up, its done evenly. You can’t just use the full payload at the rear of the vehicle. Find out what your axle ratings are, and don’t exceed them. It is easily possible to be over your rear axle weight but underweight overall.
If you run a heavy Ute Canopy on a dual cab ute, or have a heavy tow ball weight its very hard to balance your axle weights, and you can easily end up with a bent chassis.
What does it mean if I exceed the GVM, GCM, Towing Capacity or axle ratings?
The most important thing to note is your insurance ONLY covers you and your 4WD when it is driven legally. If you exceed any of the acronyms above, you risk voiding your insurance. Beyond this though, you put more stress on the four wheel drive than was intended, and risk doing damage (suspension, chassis, driveline).
You use more fuel, lose the intended handling ability and have a harder time off road. The vehicle does more damage to 4WD tracks, and your risk of getting a puncture or other damage is increased. The risks are serious, and if you cause an accident that can be attributed to your vehicle being overweight, you can go to jail and/or pay huge fines and medical costs.
If you type in ‘4×4 Bent Chassis’ into google images, you will see how many 4WD’s have had serious damage done to their 4WD’s. Often this is due to overloading or air bags on leaf sprung vehicles, but a vehicle with a lot of weight will put serious stress on the chassis and surrounding components.
Bent chassis tend to be most often on dual cabs, where there is too much weight behind the rear wheels. I took a photo up north of a hired 4WD camper, which I almost fell over when I saw. If you own a dual cab ute, check this out – Is your dual cab’s chassis likely to bend?
Can you get caught?
Don’t think like that. You don’t want to get caught. If you do, chances are it would be after an accident when something horrible has already happened. I have heard of mobile weighing stations being set up over east. Just like it is imperative that you know what modifications are legal on a 4WD, you must know how much it weights too.
Estimate the weight
I’d encourage everyone now to sit down and make a list of everything in their vehicle, and add the estimated weights up. Then, jump on Redbook and enter your vehicle in, which will tell you what the GVM, Pay load and GCVM are. If you are concerned about it being close to the limit, take it to a local weighing station and get it done properly.
Getting a GVM upgrade
Any quality suspension shop should be able to upgrade your GVM. There are kits that can be purchased for most modern vehicles from ARB and the like which will give you a bit of a boost. However, if you have an older vehicle the only way to do it is to see an engineer, and get it customized.
GVM upgrades often only involve replacing the suspension, but may also include upgrading the brakes and various other components. You can take a look at the GVM upgrade on our Dmax here – Isuzu Dmax GVM Upgrade.
Does your GCM go up?
Something worth noting is that your GCM will not normally go up if you get a GVM upgrade. This has been done in the past, but it is a grey area at the moment that the authorities are shutting down.
This poses a very serious problem for those who tow heavy trailers. Effectively you gain some pay load, but you reduce your towing capacity!
Get your GVM upgrade before you license a brand new vehicle
It is possible to get a GVM upgrade done on a brand new car before it is licensed. If this is done, then the modifications go on the licensing paper and you have much less hassle than trying to do it after the vehicle is licensed. I know a lot of people have done this with the 200 series Land Cruisers, which come with a pay load of 645kg. If you put 5 heavy adults in the vehicle, you really haven’t got anything left to play with!
What are your options if you can’t get a GVM upgrade?
As I mentioned above, if you can’t get a GVM upgrade, you need to speak to an engineer. This is a costly route, and will put most people off doing it. Other than that, all you can do is limit what you carry, or get a different vehicle.
Touring in a 4WD; is it really possible?
I believe the large majority of 4WD’s in Australia that are traveling on holidays for more than a week would be overweight, or very close to it. When you step back and look at everything that one carries, it’s seriously easy to be over.
If you are travelling for more than a couple of weeks at a time, you really need to tow a trailer, which means you can spread some of the load. No doubt some Utes would be under their GVM, but I don’t think it would be by much.
There are lots of reasons why a normal 4WD isn’t suited for what many people use them for. Is your 4WD really suitable or do you need a truck?
If you know what your 4WD weighs with all of its accessories, along with its pay load, let me know below. I’d love to know what situation you are in!