JezzerB said:
Interesting article on towing;
https://blueskyrecreation.wordpress.com/2017/06/27/85-of-kerb-weight-law-guide-or-myth/
This is almost exactly what I have been suggesting for years! (if you want to search back through all the posts on this forum)
One of the biggest problems has been that the industry advice has been hammered into people so much that they use it as if t is the law and they tend to call it a "rule" which reinforces the illusion. It is of course only advice.
I have always considered it to be wise to keep the trailers weight as small as possible, but how the figure of 85% came about is as clear as mud. I have several contacts in the industry, and none of them will admit to knowing exactly why the advice was introduced (but there is lots of speculation) and how the advice was formulated, who was involved, or the evidence that was used to produce this magical 85% figure.
The advice has become a "holy grail" for some caravanners who ignore the other important factors that affect towing and especially stability, to the extent they are actually more dangerous because of the lengths they will go to get to the magical 85% figure.
I have long believed there should be a better way of producing towing advice that actually uses the details of the vehicles involved rather than a one size fits all system. There are several matching services available both on line or over the phone which do look at more than just weight ratio's, but they are only as good as the information they have in their databases, and we know from several forum contributors that their database's do contain some significant errors. To be balanced some contributors tell us their results can be quite accurate. Most of the UK based ones will also apply the industry advice to their results and you can get conflicting results from different services based on where they are based simply becasue the weight ratio conflicts with the advice.
I'm all for advice and products that improves safety, but I'm against it if it's not corroborated by good research or logical thinking. Having said that, the industry advice has no publicly accessible information about its formulation, but it does err on the good side side of keeping trailer masses small in relation to the tow vehicle, so in teh absence of a better method at the moment I do continue to suggest its use but in combination with consideration of other factors such as proper vehicle maintenance, adoption of correct towing tyre pressures, proper loading strategies including setting nose loads, and of course sensible driving as that probably has the most significant effect on both stability and safety.