Ideally it should be 7% of your vans MTPLM (maximum technically permitted laden mass) but not exceeding the nose weight limit of the towing vehicle or tow bar.
As an example, my cars limit on the tow bar is 85 KG, I tow a 1350KG van and my nose weight is close to 7% at the 85 KG maximum of my car.
Thanks my MTPLM is 1200kgs although I think were about 1050-1100kgs laden, so at 1200kgs it would be 84kg at 7% which is too heavy. 1200kg at 6% = 72kgs and at 5.8% = 70kgs, so its it best to try at get upto 75kgs?
As above really - between 5-7% ideally of loaded vans weight.
We tow 1300kg and nose usually around 85-90kg which is max for my car and is just under the 7% guide.
The larger the van the more likely you are going to need a 4x4 to achieve 7% if that is what you are aiming for as no hatchback cars/estates/saloons have over 100kg noseweight in this country
The recommended noseweight is between 5% - 7% with a legal minimum of 4%, but do not exceed the cars noseweight limit. I tow with just over 6% with a 75kg noseweight, the cars maximum. The higher the noseweight, better stability, without exceeding any set limits of car or caravan.
Have a read of the folowing:
The "best" IMO is the heaviest the kit you have allows.
Very dated research suggested 7% but that was achievable back then with lighter weight caravans. But once caravans got over 1000kgs many cars simply could not take it and the caravan designs needed to improve to tolerate lower percentages.
What is needed is that the noseweight overwhelms the tipping back forces of air being slammed against the van front from the airflow but importantly the bow wave of passing vehicles. Providing the vehicle etc can take the noseweight there is no sensible upper limit stability wise. Dont over load but keep as high as you can.
Just weigh the van nose before you hook up, there is absolutely no need to go near or to the max you could run at 40 or 50 KG, going to the max only puts more pressure on the tow vehicle's rear suspension, that could already be put under compression with extra passengers or heavy stuff in the boot
If your van is over 1000kg loaded you do not ideally want to be running at 40kg as your van will almost certainly be more susceptible to instability from passing vehicles
Providing your car is within its loading limits and no one axle is overloaded, no problem whatsoever going to or near the tow bar/car maximum
Before I got my current tug I always had problems keeping within the 85kg car limit with my 1500kg van. Subsequently I replaced my ancient Pyramid noseweight gauge with a new Milenco one and found I had another 15kg noseweight to play with. The spring in the old gauge must have been a bit tired and was overstating the noseweight - should have checked with bathroom scales.
No problems anymore with current tug which has a 150kg limit. I find best noseweight to be 95kg, just within the Al-Ko chassis limit.