towing weight (unbraked)

HarryM1BYT · 27th January 2018, 13:43

Quote:

Originally Posted by Coups

Right then Harry. So, without a handy weighbridge to get your kerbweight how do you work out your 85%?

Right then, how about you look in your car's handbook and probably on the VIN plate too on the B pillar. From memory, my diesel's kerbweight is 1595Kg, or there abouts. The kerbweight does not vary as you add load in the car, it is fixed and quoted by the manufacturer. You seem to be of the opinion that you can change the kerbweight by adding weight in the car - that you can tow an heavier caravan by adding load into the car, that is absolutely not the case.

However, you can improve the stability of an outfit by adding load to the tug, or transferring weight from trailer to tug.

The 85% is a recommended value for the safety of those inexperienced in towing, as recommended by the caravan clubs, RAC, AA and many others to be best practice for safety.

Even for those who are experienced at towing, there are still limits to be taken into account, such as train weight, axle loading and towball loading. The 75 has a maximum towball loading of 150Kg, I tow with a 75 to 80Kg towball load and at around the 85%. Trailers have a maximum load on the ball too, my caravan has a maximum of 100Kg. Practice and feel suggests my 75 to 80Kg provides best stability for my own outfit.

Even if the trailer is legal to be towed, there are the practicalities to be considered, like has the car enough engine power and suitable gearing to cope with the extra load. My diesel easily tows on the open road, but I find first gear just a bit too high for awkward hill starts.

A trailer (or caravan) has an unladen or kerbweight, just like your car. It will also have a maximum laden weight - the difference between the two is the maximum payload - which absolutely must not be exceeded. Out of the payload comes your caravan mover system, gas bottles, clothes, TV's, water carriers and everything else you might seek to add in there. It is that maximum weight which is used in the 85% calculation.