You can't calculate an ATM as it's not an actual weight, but a maximum weight specified by the van manufacturer.

It is stamped in the vans VIN Plate.

Cheers, ozjohn.

It's always pleasure to assist.

Note:  the differnece between the TARE and the ATM is the 'Payload' or Personal Load Allowance and includes everything added onto, or into the van, including water and LPG after the van left the factory.

Cheers, ozjohn.

Cupie,
The sheet you have is a good reference, but is not absolutey correct in it's definitions.

GTM definition should include Maximum as specified by the trailer manufacturer and must not be exceeded. (similar to ATM).

Payload is not specifically specified by the vast majority of trailer manufacturers, but can be detiremened as follows:
# The difference between the TARE and the ATM.
# The difference between the TARE and the maximum permitted vehicle tow weight.
# The difference between the TARE and the maximum permissable tow weight specified by the tow bar manufacturer
Which ever is the lesser of the three.

Cheers, Ozjohn.

PS> Love ther Avatar, That's how I feel after Christmas Dinner. LOL.

-- Edited by ozjohn on Sunday 6th of November 2011 11:41:47 AM

-- Edited by ozjohn on Monday 7th of November 2011 09:44:42 AM

For the definitive definitions of things related to motor vehicles, download yourself a copy of Vehicle Standard (Australian Design Rule - Definitions and Vehicle Categories) 2005. You can download it in a PDF, DOC or ZIP file format.

Most of what you find on web pages are simplified or paraphrased versions and often leave vital bits out.

For example, here is what ist says regarding the commonly used terms:

AGGREGATE TRAILER MASS (ATM) - the total mass of the laden trailer when
carrying the maximum load recommended by the 'Manufacturer'. This will
include any mass imposed onto the drawing vehicle when the 'Combination
Vehicle' is resting on a horizontal supporting plane.

GROSS TRAILER MASS (GTM) - the mass transmitted to the ground by the 'Axle' or 'Axles' of the trailer when coupled to a drawing vehicle and carrying its maximum load approximately uniformly distributed over the load bearing area, and at which compliance with the appropriate Australian Design Rules has been or can be established.

LOAD CAPACITY - the difference between 'GVM' of the vehicle and its 'Tare Mass'.

RATED TOWING CAPACITY - the lesser of either;
- the rating given to the towing equipment fitted to the motor vehicle or,
- the difference between 'Gross Combination Mass' and 'Gross Vehicle Mass'.

TARE MASS - mass of a vehicle other than a L-group vehicle ready for service, unoccupied and unladen, with all fluid reservoirs filled to nominal capacity except for fuel, which shall be 10 litres only, and with all standard equipment and any options fitted.

Plus another 30 pages of definitions.

-- Edited by PeterD on Tuesday 8th of November 2011 04:59:10 PM

Hiya John

I was not copying from VSB-1. I was copying from this document. When you go to the Third Edition Australian Design Rules the link is just above ADR 1 - Reversing Lamps. Its heading there is "Definitions and Vehicle Categories ."