Question about legal towing limits...

jumpthemoon

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Does anyone know the actual legal regulations regarding towing weights? Ihave recently bought a trailer and now I need a vehicle to pull it. I was talking to the local garage owner the other day and he told me that I could not legally tow anything heavier than the kerbweight of my vehicle (the actual weight of the car) and the recommend is 80% of this. I always thought that you could tow up to the Gross Towing Weight of a vehicle, for example a discovery is 3500kg, but the recommend was 80% of this. If you go off the kerbweight, for a discovery its only about 2500kg. 80% of this is only 2000kg, so if my trailer weighs 1100kg, one of my horses weighs 600kg and one 400kg, I would be over the recommend without even adding water, tack, people.... Sorry to ramble on but I can't seem to fathom it from the websites I've looked at
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The legal is gross towing weight. Recommended is 80% of kerb weight. This I believe came from caravan owners club. Towing a long single axle caravan is significantly different to a short twin axle horse trailer.
 
If you go by the letter of the law, then you are quite correct, the Gross Towing Weight/train weight is the legal limit.
Would I want to be towing anything that is as heavy as the vehicle I am using? No way.
I tow a Bahill trailer with an Isuzu Trooper and carry one horse, or two ponies at a push and am inside the 80% recommendation. I accept that this recommendation has been around for a number of years and has its origins in the days when vehicles had less efficient engines/brakes but it is the weight:weight ratio I am most comfortable with
 
So I could legally tow more than the vehicles kerbweight, but I might get pushed down a hill by the trailer? Am I best to just aim to pull one horse then and keep within the 80% of kerbweight recommend?
 
Depends on a lot of factors so no easy answer.
Wheel base length plays a huge part in stability of tow vehicle.
Length from rear axle to tow ball also significantly affects the amount of sway that is transfered from trailer to tow car. The shorter the distance the better. The longer the distance is the greater the leverage the trialer has to destabilise the rear tyres.
Trailer hitch weight. Too little or too much affects the balance of the car. Handbook will give recommeded hitch weights for the car but generally around 50kg.
Quality of tyres on tow car.
Effectiveness of brakes on trailer

So .....
If you have a short wheel base car with long overhang from rear wheels with crap tyres pulling an unbalanced trailer with poor brakes you porbably wouldn't even want to get near the 80% kerb weight.
Reverse the equation and getting close to the max towing weight can be fine.
But at the end of it all it still depends on the skill of the driver.
 
I've towed two 16h2" horses in my trailer with a 2.5 TD Discovery without any problems, mine however is onlt 860kg ulw so 250kg lighter. The kerbside weight of the Discovery is 2500kg, the recommended maximum owing weight is actually 85% so 85% of 2500kg is 2125kg. Take away the trailer weight of 1100kg & the max weight of your horses etc should not exceed 1025kg. You will be just in weight.......but are you sure your one horse is 600kg? that's quite heavy, my Hann x TB 16h2" is 520kg.
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TBH its all estimates at the mo - he is 16.2 WB - quite a heavy chappy but I suppose he's maybe 550 ish. Saying that though my TB is actually about 475kg, so its about the same total. I just want to make sure that I dont end up buying a car then getting stopped for being illegal, or worse, having an acccident.
 
As correctly pointed out, the Caravan Club actually recommend 85% of the kerbweight, but in no way, shape or form is this a legal position, it was recommended because caravans typically have a high size to weight ratio, and in strong winds or when going down hills they can become difficult to control and then affect your driving ability, or even worse take control of the car altogether. Horse trailers may not be so long, but you are carrying a live load, which shifts weight and balance often, and therefore can have a similar effect.

I would always recommend that you tow with the heaviest vehicle you can, and that aside, find a vehicle with a high towing weight. 3500kg is legally the maximum weight that can be towed on road by a car, and therefore you will not come across a towing weight any higher (in manufacturer's handbooks). However, the chassis, brakes, suspension etc etc of these vehicles is designed to withstand more pressure from towing than those with say a 2500kg towing limit.

Lots of people tow above their kerbweight, and if you're experienced then this is perfectly acceptable, even the caravan club makes it clear that the 85% 'rule' is a guide, and more experienced towing drivers will be fine going above this. By getting the heaviest vehicle you can then you're heping yourself out on windy days or going down steep hills, or believe it or not everytime a coach passes you on a motorway.

I take the opposite view to 4faulter on wheel base, and have had several people that tow back up my opinion. On Short wheelbase vehicles the pivot point on a vertical plain is further back, and therefore when you load the vehicle with a trailer you often lift pressure off the front axle, which can make steering and braking more difficult because there is less contact with the road. On big 4x4s, like my Discovery, the max noseweight is 150kg, which is significant, although there are few horse trailers where this pressure will actually occur because (unless you have an ancient trailer) they all have twin-axles, and their centre of gravity is supported by these.

If you have a newer Discovery (not just the Dicos 3, but many TD5s) then you may be lucky enough to have an air suspension, which self-levels with a trailer on, therefore ensuring equal contact with the road across all four wheels.

If you're towing with a Discovery though then the one thing you can bear in mind is that legally, you'll overload the trailer before you will overload the car. Most standard horse trailers have a MAM of less then 3000kg.

When we originally started loking for tow cars, somebody told us that there are only 4 vehicles really suitable for towing 2 big horses, the LR Discovery, LR Defender, Range Rover, and Isuzu Trooper (although the towing limit on these is not so high). I think newer Shoguns and Land Cruisers are also suitable personally, although again their towing weights are lower.
 
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