Tyre Pressures

But IMHO leaving tyres at the higher pressure while solo is anything but a common sense approach where the difference is often way more than 4psi

No idea how often the required pressure increase is 'way more than 3psi'

surely the tyre pressures are set by the manufacturer and using the pacific rubber that they leave the factory with, and with that thought does everyone on this forum still use the original make as what the manufacturer fit when new. If a 35psi pressure on say a £200 tyre responds the same as a 35psi pressure on a £50 tyre then why are we all not fitting the cheaper tyre. So shouldn't we all be ringing the relevant tyre manufacturer to ask them what the pressure difference should be when towing a caravan and not taking the pressures from the vehicle maker.

Size of tyre, weight of vehicle, max speed of vehicle determines the tyre pressure .... not the make. I'd expect a £200 tyre to keep the car on the road in both the dry & rain .... a £50 of the same size & speed rating I'd expect to put me in the nearest ditch!

So it will be nothing to do with the way your driving MM. This is about pressures when towing and adjusting when required. So, some on here say they adjust every time between solo and towing. My tank takes 93 litres and 30 litres of adblue that's 123kg extra when full. Does that mean I should add air into my tyres as if I was towing I would only be putting 100kg max onto the back end as that's the max for the Alko hitch. Probably a stupid statement I know but it makes you think

Your tank is the same size as mine ..... £108 to fill it the other evening .... no idea what size the Adblue tank is 🤔 I don't add air when I fill up likewise I don't add air when I stick the caravan on the back as the weight you suggest (it'll be a bit less as a litre of diseasal is only 832g 😉) as it's not much different to sitting a big bloke on the back seat.

The way I drive with the correct air pressures is well within the capabilities of the car, if the tyres were over inflated then I'd have to slow down otherwise I'd end up with Boris in a ditch. 

Tyre pressures are usually specified for light/full load. Irrespective of whether one is towing, if you have two fat ladies and a boot full of cooking utensils then your pressures should be appropriately higher.

Thats the point, if you don't fill the car up when towing and van is at it's legal limit then no need to put air in as not fully loaded. Some think because you are towing you need to put air in and that is not always the case.

You should have added the hairy bikers as an alternative to the fat ladies as some could say your sexist cyberyacht.

All good points , i use a michelin tyre inflator as recommended for land rovers . Very reliable 6 years old , its 2 psi out ,always check with pen gauge . Front tyres should be ok its just rears for 2 hairy bikers and 2 fat ladies !!

I wonder what pressures they had in their motorbike?