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Tow Vehicle and Caravan Weight
by Andrew Woodmansey et al.
The weight relationship between tow vehicle and caravan is an important one for safe towing.
To avoid the ‘tail wagging the dog’, it is important that the tow vehicle is at least as heavy as the caravan being towed. If it’s not, the tow vehicle is unlikely to be able to control a caravan should it become unstable when impacted by external forces such as a cross wind, heavy cornering, heavy braking or uneven or slippery road surfaces.
How Much Weight Safety Margin Should I Allow?
There is some debate (and legislation in Germany) on the ideal weight safety margin between tow vehicle and caravan:
• The conventional wisdom is that the tow vehicle must be at least as heavy as the caravan being towed (i.e. a 1-to-1 ratio between tow vehicle and van weight);
• In the UK there is the “85% rule”. This is not legislated, but is a recommendation of the Camping and Caravanning Club of the UK and other UK bodies. This recommendation states that the weight of the loaded caravan should be no more than 85% of the car’s kerb weight. However, according to the Camping and Caravanning Club of the UK, ‘those who are experienced at towing may go up to 100 per cent of the car’s kerbweight, but no-one should tow a caravan that is heavier than the towing limit of the vehicle it’s behind’;
• In Germany, caravans with brakes and hydraulic shock absorbers may not (by legislation) exceed 0.8 times the empty weight of the tow vehicle unless the tow vehicle does not exceed 80 kmph;
• In Australia, there is no legislation on weight safety margins, but the Caravan Council of Australia suggests that ‘for added safety and peace of mind, the laden tow-vehicle should weigh 30% more than the laden caravan/trailer’ (for the non mathematically minded, this is the same as saying that caravan should not exceed about 77% of the laden weight of the tow vehicle);
Note that the above relates to the weight relationship between tow vehicle and caravan. There is always legislation in each country on the maximum weights of tow vehicles, caravans and towing combinations.
From the above you might think that the Caravan Council of Australia is being the most conservative of all these countries in applying a 77% safety margin. But in fact, because the CCA’s recommendations are based on laden weights of the tow vehicle and not the unladen (or kerb) weights, they are in fact the least conservative.
This can be seen from the following table, which translates these guidelines or regulations into actual weights for eight of Australia’s most popular tow vehicles:
Comparison of Tow Vehicle & Caravan Weight Relationships
What is noteworthy from this table is that the recommended (or legislated) maximum caravan weight is significantly lower in all cases than the maximum towing capacities of each tow vehicle (which ranges from 3200 kg to 3500 kg for the vehicles above).
In just the same way as tyre manufacturers stipulate maximum speeds for their tyres (sometimes 300 km/h for normal road tyres), maximum towing capacities are mechanically derived maximums, beyond which things start to fall apart. They are not intended to be fully exploited by the typical user, and especially not the novice user.
So don’t treat the maximum towing capacity of your tow vehicle like an airline luggage allowance (‘it’s there to be used’). Treat it instead as the extreme limit of your towing universe, and stay well within its boundaries.
by Andrew Woodmansey et al.
The weight relationship between tow vehicle and caravan is an important one for safe towing.
To avoid the ‘tail wagging the dog’, it is important that the tow vehicle is at least as heavy as the caravan being towed. If it’s not, the tow vehicle is unlikely to be able to control a caravan should it become unstable when impacted by external forces such as a cross wind, heavy cornering, heavy braking or uneven or slippery road surfaces.
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How Much Weight Safety Margin Should I Allow?
There is some debate (and legislation in Germany) on the ideal weight safety margin between tow vehicle and caravan:
• The conventional wisdom is that the tow vehicle must be at least as heavy as the caravan being towed (i.e. a 1-to-1 ratio between tow vehicle and van weight);
• In the UK there is the “85% rule”. This is not legislated, but is a recommendation of the Camping and Caravanning Club of the UK and other UK bodies. This recommendation states that the weight of the loaded caravan should be no more than 85% of the car’s kerb weight. However, according to the Camping and Caravanning Club of the UK, ‘those who are experienced at towing may go up to 100 per cent of the car’s kerbweight, but no-one should tow a caravan that is heavier than the towing limit of the vehicle it’s behind’;
• In Germany, caravans with brakes and hydraulic shock absorbers may not (by legislation) exceed 0.8 times the empty weight of the tow vehicle unless the tow vehicle does not exceed 80 kmph;
• In Australia, there is no legislation on weight safety margins, but the Caravan Council of Australia suggests that ‘for added safety and peace of mind, the laden tow-vehicle should weigh 30% more than the laden caravan/trailer’ (for the non mathematically minded, this is the same as saying that caravan should not exceed about 77% of the laden weight of the tow vehicle);
Note that the above relates to the weight relationship between tow vehicle and caravan. There is always legislation in each country on the maximum weights of tow vehicles, caravans and towing combinations.
From the above you might think that the Caravan Council of Australia is being the most conservative of all these countries in applying a 77% safety margin. But in fact, because the CCA’s recommendations are based on laden weights of the tow vehicle and not the unladen (or kerb) weights, they are in fact the least conservative.
This can be seen from the following table, which translates these guidelines or regulations into actual weights for eight of Australia’s most popular tow vehicles:
Comparison of Tow Vehicle & Caravan Weight Relationships
UK – Recommendations of the Camping and Caravanning Club of the UK (relates to tow vehicle kerb weight)
Germany – Federal Legislation for caravans with brakes and shock absorbers (relates to tow vehicle kerb weight)
Australia – Recommendations of the Caravan Council of Australia (relates to tow vehicle GVM)
Kerb Weight – the unladen weight of the tow vehicle without occupants or payload
GVM (Gross Vehicle Mass) – the maximum permissible laden mass of the tow vehicle including occupants and any weight applied to the towball
ATM (Aggregate Trailer Mass) – The maximum allowable laden weight of the caravan as assessed by the manufacturer
Germany – Federal Legislation for caravans with brakes and shock absorbers (relates to tow vehicle kerb weight)
Australia – Recommendations of the Caravan Council of Australia (relates to tow vehicle GVM)
Kerb Weight – the unladen weight of the tow vehicle without occupants or payload
GVM (Gross Vehicle Mass) – the maximum permissible laden mass of the tow vehicle including occupants and any weight applied to the towball
ATM (Aggregate Trailer Mass) – The maximum allowable laden weight of the caravan as assessed by the manufacturer
What is noteworthy from this table is that the recommended (or legislated) maximum caravan weight is significantly lower in all cases than the maximum towing capacities of each tow vehicle (which ranges from 3200 kg to 3500 kg for the vehicles above).
In just the same way as tyre manufacturers stipulate maximum speeds for their tyres (sometimes 300 km/h for normal road tyres), maximum towing capacities are mechanically derived maximums, beyond which things start to fall apart. They are not intended to be fully exploited by the typical user, and especially not the novice user.
So don’t treat the maximum towing capacity of your tow vehicle like an airline luggage allowance (‘it’s there to be used’). Treat it instead as the extreme limit of your towing universe, and stay well within its boundaries.
. what an idiot.
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