Le Truck?

RobertRyan wrote:

Yes they are talking about 5th wheeler GCVWR, you require air brakes. Not US bumper tow capacities which is illegal

Chevy 3500 DRW
Tow rating: 4.5 tonne
Fifth wheel: 10.2 tonne
Payload: 2.3 tonne

Also, according to Australian laws of each province, there is no such thing as "US bumper tow capacities".

"Towing Mass Limits
The maximum mass that can be towed by a vehicle is
dependent upon a number of criteria. The loaded
mass of a trailer or caravan must not exceed:
1. The rated capacity of both the tow bar and tow
coupling.
2. The towing mass specified by the vehicle
manufacturer, or the GCM (Gross Combination
Mass) specified on the vehicle’s registration
certificate.
"

Light vehicle towing trailer regulations
(GVM 4.5 tonnes or less)
Vehicle Standards Fact Sheet


"How much can you safely tow?
Most manufacturers specify towing limits for their vehicles in their handbooks. For vehicles of
Gross Vehicle Mass 4.5 tonnes or less the following limits are applicable:
• Towing limits specified by the vehicle manufacturer must not be exceeded, otherwise
safety will be compromised. Excessive loads may also damage your vehicle.
• If the vehicle's towing capacity cannot be determined, the loaded mass of the trailer must
not exceed the empty mass (tare) of the towing vehicle, excepting where the trailer is
fitted with brakes in which case the loaded mass of the trailer must not exceed 1.5 times
the empty mass of the towing vehicle."


IB-107B
Vehicle Safety and Standards
Information Bulletin
Safe Towing


"Towing vehicle
In the interests of reliability and safety, follow these rules and conditions:
• Ensure the vehicle is suitable for towing, if required, towing options such as special suspension or
transmission options or load-distributing devices, that may be fitted to the vehicle by either the
manufacturer, dealer or a firm specialising in towing equipment.
• Ensure the vehicle is properly equipped for the type and size of trailer:
• towbars and couplings must be of a suitable type and capacity;
• electrical sockets for lighting are required;
• suitable brake connections may be required;
• extra mirrors may be required for towing large trailers.
Ensure that the lower of the following is not exceeded:
• the maximum towing capacity of the motor vehicle as specified by the vehicle manufacturer; or
• the capacity of the towing apparatus fitted to the vehicle.
Note: This information can be obtained from the owner’s manual or the manufacturer. If the motor vehicle
manufacturer has not specified a maximum towing capacity or it cannot be identified, the following is taken
to be the maximum towing capacity for the purposes of the above"

Queensland Safe Towing


"Maximum Trailer Mass
Throughout Australia, the allowable maximum mass for the trailer is either the capacity of the tow vehicle’s towing attachment or the towing limit specified by the vehicle manufacturer for the towing vehicle, whichever is the least.
OR
If the vehicle’s manufacturer has not made a recommendation as to the towing mass, then the following rules apply:"

The National Caravan and Recreational Vehicle Towing Guide: Legal Requirements


None of them say anything about any kind of "US ratings do not apply" and only state that the manufacturer determines the tow rating.