RV FEATURE
GTM VERSUS ATM
Once and for all, Gross Trailer Mass (GTM) is not
the relevant rating when purely determining the
payload of a caravan or other trailer.
Tare, ATM and GTM should be engraved
on the van's compliance plate.
This magazine – and many other sources of
information – have been criticised by members
of the vanning public for correctly stating that
the difference, in kilograms, between
Aggregate Trailer Mass and Tare is a
caravan’s payload capacity.
One correspondent even threatened to report
us for falsely ‘advertising’ the payload
capabilities of various caravans in our reviews.
GTM is the relevant rating for assessing the
amount of weight resting just on the wheels of
a caravan. It is helpful in determining whether
the group axle capacity, suspension and tyre
ratings, are adequate. Unlike ATM, it does not
include ball weight.
So let’s all agree: ATM minus tare equals
Payload Capacity. Okay?
‘OFFROAD’ MEANS
‘ANYWHERE’
!
A caravan might have fancy decals that imply
an ability for the van to go anywhere the 4WD
can. It might even claim to be an ‘offroader’.
But what, exactly, constitutes ‘offroad’? A flat
field that my grandmother’s old Volvo could
traverse is technically offroad. Frankly, towed
with care, common sense, and perhaps with a
little preparation, caravans made for blacktop
touring only shouldn’t fall apart in a bit of
sand or gravel.
The term ‘offroad’ as it applies to
caravanning is quite subjective. What’s
offroad to you might be a walk in the park to
someone who has towed a rig on Cape York’s
Old Telegraph Track.
So when a manufacturer markets its caravan as
‘offroad-capable’, what does it mean? And what
are the warranty limitations, not just of the
caravan's structure but the various components,
such as the suspension or stub axles?
Never assume that ‘offroad’ means ‘anywhere’.
Now this is what I'd call offroading.
Speak to the manufacturer, read the fine print,
and employ a healthy dose of common sense
before dragging your caravan through that
creek crossing or down that rutted track.
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