GVM & ATM - what's the difference in respect to caravans?

Submitted: Thursday, Apr 30, 2015 at 20:02
ThreadID: 117679 Views:20050 Replies:6 FollowUps:9
This Thread has been Archived
Hi all,

I'm trying to do my homework properly with regard to weights as I look to buy a used caravan.

All my research seems to indicate that both GVM and ATM are the total, fully loaded weight of the vehicle.

Why is it then, that the vast majority of caravans advertised for sale which nominate both the ATM and GVM have different figures for these weights?

There is a van that I am interested in that has a TARE of 1698kg and an ATM of 2198kg stamped on the compliance plate. (GTM of 1990 is also stamped on the plate). There is no GVM on the compliance plate. When doing an online rego check of the van I noticed that there is a GVM of 1790kg listed for it.

Where would that GVM figure of 1790 have come from?

With a tare of 1698kg which figure do I use? ATM of 2198kg giving a payload of 500kg or GVM of 1790kg giving a payload of just 92kg?

Any help from someone who really knows this stuff is most welcome.

Cheers
Martin
Back Expand Un-Read 0 Moderator

Reply By: Member - Jim B8 - Thursday, Apr 30, 2015 at 20:24

Thursday, Apr 30, 2015 at 20:24
Martin
get ready for a flurry of replies, this is one subject that drags out the opinions
And this is my opinion ha ha
GVM is gross vehicle mass, the amount that is the sum of everything in the vehicle, cab/chassis, tray, bulbar, fuel, passengers, tow bar, dual battery, etc etc etc
ATM is the Aggregate trailerable mass of the van. The sum of the the van and its contents in total
Both relate to the legally maximum ratings moreso than the actual
Combine the 2, and you have the GCM, Gross Combined Mass

So GVM is for the vehicle, ATM is for the van, GCM is the combined weight of both.
Look up GCM, its the important one, that's my advice (and opinion)

Jim
AnswerID: 553120

Follow Up By: Martin66 - Thursday, Apr 30, 2015 at 20:27

Thursday, Apr 30, 2015 at 20:27
Thanks Jim, I get all that, but why then, do caravans have a GVM figure. Why does the NSW RTA have a GVM figure on the rego documents for the caravan example I gave?
0
FollowupID: 838869

Reply By: K&FT - Thursday, Apr 30, 2015 at 20:27

Thursday, Apr 30, 2015 at 20:27
G'day Martin, you are not the first person to find this a bit bewildering.

it goes like this

Tare= bare caravan with no gas, water or other "loads" on board but should include all factory fitted accessories.

GTM(GVM) Gross trailer mass= the loaded weight on the wheels.

ATM= all up weight including wheels and towball weight.

Usually ATM-GTM = ball mass

if your tow vehicle has a max tow capacity of say 3500kg then the ATM should not exceed this or the loaded weight if the ATM does exceed your max tow capacity

hope that helps

frank
AnswerID: 553121

Reply By: Notso - Thursday, Apr 30, 2015 at 20:33

Thursday, Apr 30, 2015 at 20:33
Well we have some basic weight measurements in the vanning community.

Tare Mass = the Mass (Weight) of the van without anything in it except fixtures and fittings.

GTM which means (Gross Trailer Mass) and is the maximum allowable Mass sitting on the Wheels of the van.

Ball Mass which is the Mass sitting on the tow ball of the vehicle

ATM (Aggregate Trailer Mass) which is the Maximum allowable Mass sitting on the wheels of the van (GTM) plus the Mass sitting on the tow ball of the towing vehicle (Ball Mass

You will be extremely lucky if the Tare Mass of the vehicle stamped on the plate is accurate.

Good luck.
AnswerID: 553122

Reply By: Martin66 - Thursday, Apr 30, 2015 at 20:41

Thursday, Apr 30, 2015 at 20:41
Thanks for the replies so far, I get all that, so my questions are:

1. Why is it then, that the vast majority of caravans advertised for sale which nominate both the ATM and GVM have different figures for these weights?

2. There is a van that I am interested in that has a TARE of 1698kg and an ATM of 2198kg stamped on the compliance plate. (GTM of 1990 is also stamped on the plate). There is no GVM on the compliance plate. When doing an online rego check of the van I noticed that there is a GVM of 1790kg listed for it.

Where would that GVM figure of 1790 have come from? With a tare of 1698kg which figure do I use? ATM of 2198kg giving a payload of 500kg or GVM of 1790kg giving a payload of just 92kg?

Cheers
Martin
AnswerID: 553123

Reply By: TomH - Thursday, Apr 30, 2015 at 20:43

Thursday, Apr 30, 2015 at 20:43
You have got exactly the same answers on here as you got on the Caravaners forum

Did you not believe what was said on there because the postings were accurate.

As already said ATM is NOT the total loaded weight It is a figure that the manufacturer has stated is the MAXIMUM ALLOWABLE LOADED WEIGHT.

The actual loaded weight my be different but shouldnt exceed the ATM
In some jurisdictions they do not have separate forms for the registration of Caravans and so depending on who fills it in the ATM figure may be put in the GVM line giving the same numbers but meaning a different thing

As already said again GVM normally refers to motorised vehcles.

The lowest figure should be the Tare, the highest the ATM and the middle one the GTM.

The 1790 probably came from an error in input by an unknowing operator.
AnswerID: 553125

Follow Up By: Martin66 - Thursday, Apr 30, 2015 at 21:03

Thursday, Apr 30, 2015 at 21:03
Tom, The questions I asked on the caravanners forum were not answered which is why I'm now asking here.

I'm not after explanations on what the ATM, GVM etc mean. I already know that.

Your suggestion regarding the RTA forms could be something to do with it but there is no 1790 figure in any field on the compliance plate in the example I've given here so that doesn't answer my query either.

To put things simply: I am contemplatiing the purchase of a van that has a tare of 1698kg. There is a ATM figure of 2198kg on the compliance plate and a GVM figure of 1790kg on RTA records. Legally, do I have a payload of 92kg or 500kg?
0
FollowupID: 838872

Follow Up By: TomH - Thursday, Apr 30, 2015 at 21:05

Thursday, Apr 30, 2015 at 21:05
500 plain and simple if its on the plate
0
FollowupID: 838874

Follow Up By: TomH - Thursday, Apr 30, 2015 at 21:06

Thursday, Apr 30, 2015 at 21:06
You incorrectly stated the definition of ATM thats why I posted what I did
0
FollowupID: 838875

Follow Up By: Martin66 - Thursday, Apr 30, 2015 at 21:31

Thursday, Apr 30, 2015 at 21:31
I didn't actually give a definition of ATM. I was clarifying that the ATM is obtained by using an actual weighing device and that manufacturers do nominate a maximum ATM on the compliance plate.

This was after looking at the Caravan and Camping Industry Association NSW definition: ATM (Aggregate Trailer Mass)
The total laden weight of a trailer, which includes the tow ball mass and whatever you add as payload (eg. water, gas, luggage). The ATM is specified by the trailer manufacturer and must not be exceeded.

When refering to the actual total weight including payload, what would that figure be called if ATM is incorrect?
0
FollowupID: 838876

Follow Up By: TomH - Thursday, Apr 30, 2015 at 22:06

Thursday, Apr 30, 2015 at 22:06
The actual loaded weight is the weight when fully loaded and should not exceed the ATM There is no definition for it as such.as it will vary depending on how much groceries you bought on the day you weigh it or the varying amount of water in the tanks..
The ATM is not a weighed figure. It can be worked out by taking the capacity of the parts needed to support the van and plated as such. Im sure they dont load one up to see what it should be.
0
FollowupID: 838879

Follow Up By: Martin66 - Thursday, Apr 30, 2015 at 22:16

Thursday, Apr 30, 2015 at 22:16
I am quite satisfied with the Caravan and Camping Industry Association NSW definition. Thanks for your help though Tom.
0
FollowupID: 838881

Reply By: Rangiephil - Thursday, Apr 30, 2015 at 21:52

Thursday, Apr 30, 2015 at 21:52
There is a van that I am interested in that has a TARE of 1698kg and an ATM of 2198kg stamped on the compliance plate. (GTM of 1990 is also stamped on the plate). There is no GVM on the compliance plate.

My guess is that the van has had options fitted eg air conditioner, and has been reweighed and the weighbridge certificate supplied to the RMS at 1790Kg Tare.
The RMS has then made a mistake in not calling the weight Tare but GVM.
As caravan builders are notoriously lazy, nobody probably changed the ID plate.

The correct procedure as I was told recently by a trailer manufacturer, is to get a blue slip that the caravan complies with ADRs, have it weighed, take the paperwork to the RMS, which will amend the rego weights and then take it to a trailer manufacturer( or the original manufacturer) who will stamp up a new ID plate.
Regards Philip A
AnswerID: 553127

Follow Up By: Martin66 - Thursday, Apr 30, 2015 at 22:02

Thursday, Apr 30, 2015 at 22:02
Ok, thanks for that suggestion Phil. That all sounds like a possibility. The caravan is from interstate which is the reason that I'm trying to get some answers. I want the correct certification and don't want problems when I go through the process of getting it registered in the ACT.
0
FollowupID: 838878

Follow Up By: TomH - Thursday, Apr 30, 2015 at 22:12

Thursday, Apr 30, 2015 at 22:12
Best of luck with that. My first van was considerably over on the tare and to rectify it I had to get an engineer to certify it and get a SECOND plate which had to be placed beside the original one. Very few manufacturers will replate a second hand van sight unseen.

Not what I was told. Was what I actually experienced.

Reflects what was said in a long thread on the Caravaners Forum
0
FollowupID: 838880

Sponsored Links

Popular Products (13)