The 85% rule explained

Whether new to the past time or a seasoned caravanner, one of the most important points to consider is the match between your tourer and the vehicle you will be towing it with. 

Most caravan insurance customers are sensible enough to realise that it is both unsafe and impractical to tow a caravan that is heavier than the legal limit of their car or beyond the limits set by their experience – or lack of it.

However, it still happens and those taking the risk of driving a mismatched outfit are liable to a fine, points on their licence and invalid insurance, not to mention a nasty accident.

‘The 85% rule’ is often quoted as the 11th caravan commandment (behind thou shalt not pack everything but the kitchen sink). It is not a legal requirement but a useful guideline for ensuring you stay within a limit that is safe and that suits your car and your towing ability.

For some, however, the 85% rule remains a thing of mystery - as unfathomable as football’s offside rule and the contents of a lady’s handbag.

  • How to apply the 85% rule

    ‘The 85% rule’ dictates that the gross weight of the item being towed, i.e. a caravan or trailer tent etc, should be no more than 85% of the kerb weight quoted for your towing vehicle.

    To apply the rule you need to correctly calculate 85% of your car’s kerb weight… cue pencil, paper and the Countdown theme tune.

    To do this you will need to:

    • Know your car's kerb weight and its maximum towing weight for a braked trailer – you’ll find this in the your car's handbook or on the manufacturer’s website
    • Use whichever of the above figures is the lowest to calculate the 85% figure
    • Divide the kerb weight (or maximum towing weight - whichever is the lowest) by 100 and then multiply this figure by 85.

    You should now have worked out what your 85% target is and if you choose a caravan with a ‘Maximum Technically Permitted Laden Mass’ (that’s the caravan's weight plus the weight of all your caravanning gear) of about the same value you should be able to tow safely.

    Most caravanning and camping organisations recommend that anyone towing a caravan or trailer follow the 85% rule, especially those who have limited experienced towing.

    More experienced towers may feel capable of towing up to their car’s legal limit but it is important to remember that the towing limit of a vehicle is an indication of it’s mechanical capability – it has not been determined by the stability of the item being towed. 

    In perfect driving conditions; with no crosswinds, uneven road surfaces, air turbulence from lorries or unpredictable drivers, then 100% of the towing capability of a car could be applied for all caravanners. As these road conditions are very rare, it is wise to be cautious and apply the 85% rule.

    Some caravanners feel that the 85% rule is outdated and that the range of new electronic devices created to help improve stability will permit them to push the weight boundaries to the limit, and beyond, but safety should and must be paramount when taking to the road with your caravan in tow.

    Expect the best and prepare for the worst! Insure your Caravan.