10/04/2026
Interesting read here from Ken
ARE WE EXPECTING TOO MUCH FROM OUR DUAL CAB UTES?
What you read in the glossy brochure for any vehicle may NOT be applicable in a real-life situation, however this basic message can be used on all vehicles.
Do your research before committing to any vehicle purchase.
The various makes and models of dual cab utilities, that we see every day on our roads, are one of the highest selling categories of vehicles on the Australian roads.
These include the popular Ford, Toyota, Mazda, Isuzu, and other makes of vehicles. They are a very versatile workhorse for the family, tradesperson, horse owner, camper or caravanner.
I have owned several dual cab utes over the years and at the time of writing I still own a Ford Ranger dual cab ute. They are a very versatile vehicle and great for the purpose for which they were built. However, like all vehicles they all have their limitations on correct usage. Many are simply pushed to their limits and beyond by drivers without an understanding of the legalities, weights and the basic physics involved.
I have found two main common concerns with their usage, and neither is usually a fault with the vehicle, but the fault with the driver.
These include: -
1. Overloading more than the vehicles GCM (Gross Combined Mass).
2. Broken chassis.
LET’S LOOK AT THESE CONCERNS.
OVERLOADING THE VEHICLES WHEN TOWING A LARGE CARAVAN OR TRAILER.
The most common fault is drivers not understanding or following the manufacturers maximum weight limits, and then overloading these vehicles. A lot of the confusion around the weights can be attributed to people believing the manufacturers marketing hype. While this section uses dual cab utes as the example, the basic principles can be applied to all vehicles.
While actual weights will vary from makes and models, the most common dual cab utes (Hilux, BT-50, Ranger, D-Max and many others) have manufacturers compliance plates stating the following approximate weights: -
Some vary depending on makes, and the newer constantly changing models etc.
Kerb weight (Tare or as manufactured weight plus a full tank of fuel), of around 2,200 kgs – Unloaded with full tank of fuel.
GVM (Gross Vehicle Mass) of approximately 3,200 kgs – fully loaded with driver and all passengers and including ALL accessories like bull bar and canopy etc.
GCM (Gross Combined Mass) of 6,000 kgs – Total allowed weight of the fully loaded vehicle and any trailer / caravan under tow. My Ranger comes in this category.
The latest models of some now have a slightly higher GCM rating of around 6,400 kgs, and weights vary, however, many on the roads today have a 6,000 GCM or less.
BTC (Braked Towing Capacity) of 3,500 kgs – Total weight of the fully loaded braked trailer under tow.
Tow Ball Weight of 350 kgs – being the maximum download that the tow hitch can have from any trailer attached to the tow hitch. Usually set by the manufacturers as being 10% of the braked towing capacity.
While these vehicles are extensively advertised as having the 3,500 kgs towing capacity, in a real-life situation the towing capacity can be considerably less, resulting in many being overloaded in the GCM. But let’s not let the facts get in the road of a good advertising pitch.
It should be noted that I usually use the Kerb weight not Tare weight in calculations, as this includes a full tank of fuel, where Tare weight includes only 10 lt of fuel and can cause confusion calculating remaining fuel weight as load.
Firstly, a heavier vehicle, in this case, potentially the caravan being towed at 3,500 kgs, (the rated towing capacity) will tend to push a lighter tow vehicle, the ute at only 3,200kgs, (the rated GVM) around in any caravan sway or emergency event. It is desired that the tow vehicle should always be controlling the caravan and not vice versa.
The loaded tow vehicle should always be heavier than the loaded caravan it is towing. This is very basic physics, and the reason sumo wrestlers are heavy people, and we have different weight classes in contact sports. Why are hammer throwers at the Olympics such muscular and heavy athletes? They need to be able to counteract the centrifugal forces and weight to maintain control of the hammer being swung around.
Therefore, while on paper, the 3,500 kg braked towing capacity may be correct as a towing capacity stated by the manufacturer, any trailer / caravan being heavier than the tow vehicle is unrealistic in real life and may also become a dangerous hard to control rig in any emergency situation.
Yes, the vehicle may pass all the Australian testing standards applying the towing capacity rating. These can include braking, acceleration, uphill towing and chassis strength but they do not always cover commonsense, emergency sway and safe towing practice.
Safe towing practice also allows for a 10% safety margin. 3,200 kg GVM less 10% safety margin = 2,880 kg ATM trailer or caravan. Let’s remember that figure of 2,880 kgs towing capacity.
Secondly, the dual cab ute fully loaded at 3,200 kgs (GVM max) and towing a caravan at 3,500kgs (The rated towing capacity) means that the actual Gross Combined Mass of the combined rig is (3,200 + 3,500 = 6,700) 6,700 kgs.
However, the manufacturer has stated that the maximum Gross Combined Mass of that vehicle cannot exceed 6,000kgs.
Therefore, when fully loaded and towing to maximum towing capacity, the rig is effectively 700 kgs overweight with no safety margin. Apart from being very unsafe, this may result in a hefty fine from authorities and the loss of points off your licence driver and insurance voided.
A ute with a 6,000 kg GCM, less a 3,500 kg caravan only leaves (6,000 less 3,500 = 2,500) 2,500 kgs for the fully loaded ute. As the unloaded ute’s kerb weight is 2,200kgs that only leaves (2,500 less 2.200 = 300) 300 kgs for driver passenger and all the other extras added or loaded onto the ute.
For example: -
All these items have weight and need to be added to the actual GVM weight if included on the vehicle.
• Bull bar.
• Canopy
• Drawers in the tray
• Fridge and contents
• UHF radio
• Long range fuel tanks and fuel contents
• Tools, second battery
• Camping gear
• Roof racks and roof load like a tinnie, awning etc.
• Driver
• Passengers
There is more than 300 kgs in that list.
A more realistic towing capacity is around 2,800 kgs for these vehicles when you include the following everyday items found on the dual cab ute. Remember that 2,880 figure from above.
The 6,000 kgs GCM less a caravan of 2,800 kgs ATM leaves a tow vehicle total weight capacity of 3,200 kgs or the original GVM of the dual cab ute.
3,200 kgs less the tow ball weight (10% of the van ATM of 2,800 kgs) of 280 kgs still leaves 2,920 kgs for the vehicle, driver, passengers, accessories, and load.
2,920 kgs less ute Kerb weight of 2,200 means you can now carry approximately 720 kgs of load and added vehicle accessories as per above.
This 720 kgs remaining load capacity is far more realistic for the average caravanner and family. After all, you bought a ute to carry stuff in the tray.
It is a legal requirement that all vehicles on the Australian roads weigh less than the manufacturers compliance plated weights. An overweight vehicle will be classed as un-roadworthy and driver subject to infringement notices.
A check of your vehicle insurance policy will show almost all insurance companies state that the policy is voided if the vehicle is overweight and / or un-roadworthy.
Remember, when hitched to the caravan, the van tow ball weight shifts to the ute and needs to be added to the load on the vehicle and included in the maximum GVM figure.
The tow ball weight should NOT be included in calculations twice. Therefore, when hitched, the actual tow ball weight is added to the ute, and the caravan GTM figure (Caravan actual weight on the tyres only) is used and added to find the actual GCM.
It can be confusing, but basically the ute’s actual GVM added to the caravan’s actual GTM figurer will give you the actual GCM total.
I use the manufacturers GCM, GVM and vans ATM figurers when calculating the basic ‘capacity to tow’ as the towing capacity figure used by the manufacturers, is for the van ATM figure. However, when doing final figures on loading for GVM calculations the tow ball weight will need to be added to the ute load and taken off the van. (ATM less TBW = GTM) You may need to read that again as it can be confusing until you get used to it.
THE BROKEN CHASSIS.
A quick search of the internet will show many photos of dual cab utes with broken chassis. The chassis will often break or bend just between the cab and tray.
This is not usually the fault of the vehicle. It can mostly be the fault of the owner pushing that vehicle beyond it’s design limits by adding extra weight and leverage on the chassis that it was not designed for. Once again basic physics places a big part.
Why does this happen and how can we help prevent it?
The typical dual cab ute consists of two individual, and not connected body parts, being a cab and a tray or load area. Both are bolted to the one chassis.
By comparison a wagon or SUV consists of one body part, a full-length cab or passenger compartment which includes the load carrying area, bolted to a relatively full-length chassis. The cab structure adds strength to the chassis as there is no separate parts from front to rear. It can be like the arch on the Sydney Harbour Bridge adding strength to the road sub-framework.
Have a look at a side on photo of one of the popular dual cab utes, especially one with a tray and canopy fitted. You will typically, immediately be able to see a major cause of the problem.
Two separate parts – cabin and tray, not joined in any way apart from the chassis.
Figure 59. A dual cab ute has a cantilevered rear tray with approximately 2/3 or more overhanging rear of the rear axle. The red vertical line shows the rear axle position in relation to the tray / tub overhang. The front cab and tray are two separate body parts. Photo courtesy Bundaberg Toyota.
Draw a vertical line, up from the centre of the rear axle through the tray. You will note that there is approximately ¼ to 1/3 of the tray forward of the rear axle and the vast majority ¾ to 2/3 rear of the axle causing a large rear overhang.
This overhang places stresses on the chassis at a point between the cab and tray as the weights front and rear try and bend the chassis at that point between the cab and tray. Added to this stress is the extra weight of any caravan or trailer attached to an overhung tow hitch, which is even further rear of the tray or tub. Under normal operating and loading conditions, the vehicle is well within its design limits and there are usually few issues.
The problems come when drivers start adding custom trays, canopies, and heavy weights to that rear overhang, compounding the stresses on the chassis point between the cabin and tray. These stress limits can be exceeded when the ute and caravan / trailer in tow, go over undulating ground and the result can be a cracked chassis and a banana shaped chassis ute.
The large and heavy canopies added aftermarket may also have attachments on the rear to carry one or two large and very heavy ‘light truck’ tyres. These tyres and rims can weigh 40kgs each and above. Some also have jerry can holders fitted.
We usually also load heavy equipment and items onto the rear of the tray for convenience and easier access. Items like fridge and slides are often found at the rear compounding the overhang weight.
Trailers and caravans are attached via an overhung hitch, often extending further rear beyond the tray. These tow ball download weights can often be around 280 to 300 kgs and up to 350kgs for a medium/ heavy sized van.
The greater the distance from rear axle to the tow hitch the greater the leverage and additional weight and stress on components. It is like using a longer crowbar to move a load for better leverage.
Due to the rear tray, often the tow hitch may be extended to allow the caravan / trailer hitch to not foul on the tray. This increases the leverage further on the chassis.
While the actual download weight may be 300 kgs, (for example) the actual weight placed on the rear axle by the tow hitch can be over 400 to 450kgs of weight added to the rear axle by the leverage of weight off the front axles by the see saw effect. (150% weight shift from hitch to rear axle is common.)
I strongly recommend that if you have an aftermarket canopy, that you get your fully loaded vehicle weighed, especially if towing a trailer, van or camper. So do your homework as you may be surprised with what you find. The weight of the actual canopy and accessories will need to factor in to the GVM weight reducing load capacity for carrying ‘stuff”.
We have all seen the front of the vehicle lift and rear sag when we hook up a heavy trailer to the tow hitch. This is the leverage and the weight lifted off the front axle and transfers to the rear axle via the chassis as the lever.
So now we have two very heavy cantilevered weights trying to break our chassis between the cab and tray. It is like snapping a stick, it will flex to a point before breaking.
The ute may travel well with these loads under normal conditions and may well be within design limits, and no concerns in handling or performance noted by the driver.
Now, Sir Isaac Newton comes into play and his findings in basic physics.
The whole rig is subject to the ups and downs of travel on our roads, tracks, beaches, and other places that we like to venture. That is why we bought a four-wheel drive vehicle.
As the rig travels through a culvert, dip in the beach, road or track for example, especially at speed, the cantilevered weight on the tray overhang and the tow hitch may travel downwards initially when travelling through the culvert then violently be forced upwards as the vehicle exits the culvert.
The heavy overhang is subject to inertia when it wants to continue travelling in the downward direction and is then forced upwards with the rest of the vehicle. This extra stress caused by the inertia can be enough to snap the chassis.
More stresses are forced on the chassis as the caravan wheels go through the culvert or dip and the resultant up and down movement on the hitch again stresses the chassis.
It is these excessive stresses that can cause the chassis to break.
Many on social media will tell you that it is air bags that cause the chassis failures. While I do not state that air bags don't contribute to some extent, to say that air bags are the main cause, when many broken chassis vehicles did not even have them fitted is foolish.
The facts are that many of the vehicles with the broken chassis did not even have air bags fitted. So, I must ask how air bags caused the problem if not fitted to the vehicle?
Many will tell you that the chassis is not designed to have air bags fitted and that they place excessive forces on the chassis at a place it is not designed to have these forces applied causing the fractures.
If you take a look at where the air bags are fitted, you will note that there is usually extra reinforcing welded to that area of the chassis where the bump stops, and air bags are fitted. It is designed for impact with the factory fitted bump stops.
This part of the chassis is designed to have high impact from the bump stop when the vehicle suspension bottoms out. While I agree it is not standard and will place different stresses on any chassis it should be able to handle an air bag if used correctly.
There are many reports on drivers pumping the air bags to extreme levels to try and compensate for overloading the vehicles suspension. A fully inflated air bag is rock hard and usually eliminates any spring travel, meaning there is basically no suspension working to soften any shock loads on the vehicle. This can lead to chassis damage and bending when being used in rough environments. Once again this is a driver induced problem, not a vehicle fault. Only use air bags as per manufacturer’s instructions.
My advice, is to use common sense, have a read of Sir Isaac Newton’s laws of physics and don’t believe everything you are told or read on social media.
Think about the impact of any changes you make to your vehicle.
Be aware of the causes of common problems and design your rig set up accordingly.
Be cautious of advice from people wanting to sell you something especially heavy, badly designed canopies that create heavy overhangs not included in the original manufacturers design specifications. Discuss options with the canopy manufacturer. Strengthen chassis for example.
Ask what do they weigh, and how will they affect the vehicle? Every vehicle has design limits and if you want to exceed them, buy a bigger vehicle.
The dual cab utes are a very versatile vehicle and one of the largest selling vehicles in the Australian market. They can be a great vehicle for towing within their design limits just like any other vehicle.
Let's all stay safe, do some research, and use common sense when setting up a vehicle beyond that provided by the manufacturer.
This and much more caravan safety information can be found in our book -
SAFE CARAVAN TOWING - THE MANUAL
available from the Truck Friendly caravan road safety program web site in E-Book or printed copy.
https://www.truckfriendly.com.au/safe-caravan-towing-the-manual/
Cheers
Ken Wilson
Truck Friendly caravan road safety program
[email protected]
0429944663
