Understanding Vehicle Weights
Published by Peter Harris on 29th Aug 2017
Is your 4X4 Overloaded?
Okay, first things first. Understand your weights and your terms: Tare, Kerb, GVM and GCM. One of the tricky things in understanding all of these terms is that they do vary slightly from different manufacturers. With that said, here is the simplest way:
Tare Weight: is your vehicle as it rolled off the showroom floor, full of fluids and ten litres of fuel. Sometimes it includes a 75kg driver, sometimes it doesn’t.
Kerb Weight: This is your real-world weight, as if it’s parked on the kerb and ready to drive. This includes accessories and other inclusions, plus a full tank of fuel. Want to know your kerb weight? Then get yourself to a weighbridge.
GVM (Gross Vehicle Mass): This is the most the vehicle is allowed to weigh overall, under any circumstances. This includes everything, so minus your kerb weight from your GVM to find out your payloads.
GCM (Gross Combination Mass): This is an important one if you’re towing. Aside from the GVM and trailer ATM (Aggregate Trailer Mass), GCM sits atop it all.
What’s important to note here is that in real life your maximum towing capacity and your GVM don’t add up to your GCM. In other words, you often can’t max out both at the same time. There are other considerations such as ball weight - the amount of weight your trailer or caravan is carried by the towing vehicle.
Let’s look at two examples, Toyota 150 Series Prado and 200 Series LandCruiser:
LandCruiser 200 GXL | Prado 150 GXL | |
Tare Weight | 2,630kg | 2,235kg |
Kerb Weight | 2,740kg | 2,315kg |
GVM | 3,300kg | 3,000kg |
Payload | 560kg | 685kg |
Braked Towing Capacity | 3,500kg | 2,500kg |
GCM | 6,800kg | 5,500kg |
So, is your payload always going to be enough? If you’re dawdling around town with a couple of passengers, you’ll be fine. But if you’re going to fit some common modifications and tow some decent loads, then you might run into trouble.
Think about your passengers
Now, don’t go putting everyone on the scales before stepping into the car. You might lose all of your friends. But, this point is worth thinking about. Think about travelling with five adults, which could easily account for up to 500kg of mass. Throw in a few accessories, and you could be teetering on the edge…
Think about your accessories
Everyone wants the tricked-out touring rig that has all of the bells and whistles, but don’t forget they all add kilos.
Your biggest culprits are obviously barwork: bullbars, roof racks and other bolt-on steel all add significant weight. Drawers, fridges and slides are also big ones, plus things like recovery gear, compressors and tools that live in your car full-time. Don’t forget, everything adds up.
On top of this, there are plenty of hidden weights you’ll probably overlook. If you’ve fitted tyres with a light-truck construction, that’s good news. They’re stronger and more puncture-resistant, but they will also weigh a bit more. So will fade-resistant heavy-duty aftermarket springs and shocks.
Our best advice is to take your 4X4 over a weighbridge, to really know what your 4WD weighs.
Some examples of typical weights of accessories include:
ALLOY BULLBAR 35KG | STEEL BULLBAR 75KG |
WINCH 45KG | DUAL BATTERY 25KG |
SPOTLIGHTS 5KG | TOWBAR 25KG |
ROOFCAGE ALLOY 20KG | ROOFCAGE STEEL 50KG |
EXTRA FUEL TANK 100KG | SPARE WHEEL CARRIER 45KG |
REAR DRAWS 100 KG | WATER TANK 100LTR |
ALUMINIUM TRAY 150KG | STEEL TRAY 400KG |
DOG CAGE 40KG | LPG TANK 100KG FULL |
ROOF TOP TENT 60KG | 50L FRIDGE 30KG |
TOOL BOX X 1 100KG | LUGGAGE 100-300KG |
TOWING 100-300KG | PASSENGERS |
What can you do to fix the problem?
If you’ve a 4X4 that’s well set up for touring and off-roading, one of the best and easiest ways to keep your 4X4 safe and legal is to fit a GVM upgrade.
This can often give you an extra 500 kilograms on your GVM, which means you can haul and tow lots more legally.
They often consist of replacement springs and shocks for your 4X4. But most importantly, the upgrades are engineered to suit the increased payload, and come with a certificate of compliance.
Our GVM upgrade partner - Lovells Springs - holds Compliance Plate Approvals as a Second Stage Manufacturer (SSM) of GVM upgrades for several makes of vehicle including:
- Toyota
- Nissan
- Ford
- Isuzu
- Mazda
They are steadily expanding the range of vehicles for which they offer this upgrade.
But a comprensive vehicle list can be found in our Lovell Spring promotional page, take a look at it here.
All Four x 4 Spares has been assessed by the SSM and we have been registered with the Federal Department of Transport and Regional Services as a Production Facility.
This allows us to supply, fit, obtain engineering approval and submit paperwork to the relevant agencies to have your vehicles GVM officially increased.
Do you think yourvehicle needs a GVM Suspension Upgrade and you would like to speak to one of our suspension specialists? No worries, you can reach us in different ways:
CALL US on: 02 4041 4080
or
EMAIL US at: offroad@allfourx4.com.au
A Video is worth a Million Words...
Watch the videos below on Lovells GVM upgrades we have fitted:
Want to know more?
Read our blog GVM / BTC Upgrades - what are they and why are they important? to get a deeper understanding of the topic.
If you are ready to make a Booking, you can contact us at one of the methods listed above or simply GET A QUOTE HERE and we'll get back to you within 4 business hours.