Another nose weight question

It is irrelevant, if the car isn’t type approved for towing then its towing limit is 0kg. If it is type approved there will be manufacturers details of max train weight and max towing weight. It may be less, the same as or more than the ‘kerb’ weight. 

As flatcoat says, the max weight your car can legally tow will be on the weight plate/in handbook.

if you're towing on just a Cat B licence(for which the trailer legally has to weight less than the car), it's the UNLADEN weight of your car that matters, so putting weight in it or (on the towbar) is irrelevant. It's also based on the Max (MTLPM) weight of the caravan, not what it actually weighs (so stripping a van out to shed weight makes no difference in law, it's what is on the weight plate that matters)

The guidance that it's best to tow a trailer with max 85% the weight of your towcar is also based on unladen/kerb weight, otherwise it would suggest that filling your boot with bags of sand would mean the car will then tow a heavier caravan...

Markflip's statement that, on a Category B licence, the trailer legally has to weigh less than the car is incorrect.

As Flatcoat says, the statutory plate on the car will give details of its permissible weight (GVW) and its gross train weight, if it is type approved for towing. Subtract the weight of the car from the train weight will tell you what you may tow. If the car is already loaded right up to its GVW limit when solo, then adding the noseweight of the trailer after the trailer is hitched up will result in the car being overweight by the amount of the noseweight.

I am on about the weight ratios between caravan and car for the 85%  do i add the max noseweight of the towbar to the weight of the car or just as the car is without the noseweight 

Just as the car, the nose weight stated is simply the load capacity of the bar/vehicle.

What is the relevance of 85%? I Assume you are referring to the utterly misleading and oft misunderstood guidance that has no legal basis? And if you are, the 100kg noseweight you refer to is about 5.5% of your vehicles kerb weight, and i defy anyone to be able to tell the difference between 85% and 90.5% ratio of weight when towing. You dont suddenly become unsafe at 86%! I would concentrate more with a) being legal and b) having a balanced set up. 

"You dont suddenly become unsafe at 86%!"

Phew, thank goodness for that. I was at 86% when I was tugging.

Weight ratio is based on the car's kerbweight, i.e. no payload. For that reason, noseweight doesn't come into the picture because noseweight is part of the payload.

Ok cool, it was just as nice person on here posted ip a link to an outfit matching service and it takes added payload into consideration when doing the calculation and just wondered if the added weight towbar limit was used too

Maybe i am tired and my brain isn’t functioning well but i still don’t understand why the noseweight is critical to your towing weight ratio. It would be a lot simpler to look at the ‘kerb’ weight of the (A) tow car, the MTPLM of the (B) caravan and if B is less than A you are towing at less than 100% weight ratio using the NCC methodology. It dorsn’t mean you are legal (for example if the max train weight is exceeded or the max legal type approved certified towing weight of the car is less than ‘B’). Assuming everything else is legal can you explain precisely what the problem is?