collected tire myths.

Overloaded tyres will deform the side-wall, make them blow out like an under-inflated tyre, which damaged the strengthening bits, like running on a flat.
The tyre will roll more into a corner, and out again, giving understeer to oversteer changes that are an absolute hoot when you are driving a heavy load, honestly, especially when your at speed.... [/sarcasm]
The tyre will perform like it has been under-inflated.
The danger there is those who will add more air to square it up again.
They risk the chance of blow outs at high speed.
Its not the pressure inside the tyre that aids handling, its the actual shape of the tyre where it hits the road.

Its not that subtle, when driving a small transit (one ton) van, look at the tyres.
If the tyres had been at the right pressure but are now bowed out at the bottom, and you cant get a fist on top of the tyre because its too high up in the wheel arch, you are overloaded.

I cant do the maths, but I can suggest what the maths may be.
Taking a simple twin axle trailer, four double tyres making eight in all, at the "right" pressure, holding up say a ten ton trailer.[part loaded]

Add a further 20 tons.

For simplicity sake, we will ignore the fact that some of the weight is distributed through the fifth wheel, buy stating that this extra load has been balanced equally over the rear axles.
[yes you can do that if you know what your doing...]
[no you WOULDNT do that if you want traction at the cab end...]

You are now adding an extra 2.5 tons in weight per tyre.
This is why double wheel axles are used, to spread the weight that way, and thats why you see up to six double wheels, making 12 tyres, on some trailers, those are usually used for heavy weights, where as the 6 single wheels are used for bulky objects where loaded is full by size not weight, and some 4 tyre trailers for extremely light weight loads.

So saying, if you then chose to re-load that trailer onto a single tyre wheel configuration, that would double the weight on that tyre, an extra 5 tons per tyre.

The reason I cant do the maths is because I dont know the tyres that well, some are built to take more weight than others, have thicker side walls, and will deform less, thus the change in internal pressure is less.

But thankfully, those tyres start out at a LOT more than the usual car pressure of ~35~ per wheel, even small transit vans start off with 55psi, so the change in pressure on a loaded wagon will be easier to spot in single psi figures, but, on the other hand, there is more air in there to start with, so it compresses less per square inch of air-space?...
So, if you put 5 tons over a car tyre, it will deform (almost flat) far more than if you put the same on a Truck tyre, therefore, the increase in pressure will be more on a car tyre..... I *think*, I aint sure on that one.
Car tyres are smaller, therefore, they have less air to be compressed, so pressure increase will be more per square inch?... thats the *obvious* here isnt it?..

Its also why Truck tyres are a lot bigger than car tyres, more air space to compress, therefore, they take change in weight a lot better.

It is a front engine car isnt it?.. jus' checking you aint got a hang-it-out-the-back thing...

Yes do that, if you have a sensitive enough gauge, you will see maybe a 2psi change on a heavy car... and I suspect you have a heavy American truck your doing that on?...

Take that silver thing, load it to the max, take pressure reading of all tyres, unload and get it in jack stands, take pressure again.

Unless you are brave enough to lift a boot on one corner at a time with a jack?..
I have a trolley jack I can trust to do that with.

So you would have to take the wheels off to check tyre pressure?...
Bloody silly idea, when Tyre pressure should be monitored weekly at least......

Another "Myth".....
this involves "Enthusiasts" who prefer "Concourse" condition cars.
The tyres they had when antique cars were invented would be illegal today.
So unless you have modern tyres, you cant drive a fully historically correct car on the road.

I do not know how much of that is truth.....

I have, however, been embroiled in a tense argument when I argued that if I owned a certain antique car, the first thing I would do is fit seat belts.

Seat belt law in UK is "Only if fitted as standard", and older cars who did NOT have belts fitted when new, are "Exempt", as no law forces retro-fit....
I think thats bloody silly, but again, see above, you would serially offend the offended who would "devalue" the vehicle if you fitted modern stuff, like safety equipment....

I suggested a bright orange harness fitted to safe anchor points on the vehicle that could be removed if required.

Still no dice, even if removable, it devalues the car if you have ever used them....

I say the person I was arguing with was a bloody fool.

I also say that if the designers of the vehicle at that time "Knew what we know now", they would have fitted belts.

The German regulations for vehicles is rather simple: "Whatever was legal when the car was first licensed is still legal today". This is basically adopted by the EU and in use for most European countries before the European Union laws came up.

For example, reversing lights are not mandatory until the mid 1970s. Before they became mandatory for "new cars", they were just meant for your convenience. Originally you had to tap the brakes to see where you are going in the dark or switch on the fog light if you have one. My dad's 1967 Hanomag furniture delivery truck was equipped lots of extras. There was an additional switch which activated two spotlights. One inside the cargo hold of the truck and one sitting on the rear bumper which had a 15ft cable and was detachable. It was useful to load/unload or for repairs in the dark and it doubled as reversing light.
Modern cars must have at least one reversing light, the wattage and beam characteristic is defined by rules and it must be controlled by the gearbox. The current German regulation is half a page. The EU adoption is 60 pages...
The reason why they are mandatory today is that they are now also used as a visual clue that the car is in reverse gear and may back up. But you don't have to retrofit and the system of my dads truck would be still legal today. Just activating the light while driving forward would be illegal.

For seat belts, if the car has seat belts (retrofitted or not) you must use them and you may not remove them. If the car was never equipped with seat belts, you don't need to retrofit them and obviously you don't need to use them.
Seat belts and their benefit was long known before they became mandatory (for new cars). But there are reasons why most cars didn't came with seat belts.
First of all, back then idiots couldn't afford to own a car, cars were slow and there were not many cars on the roads. So accidents were very rare. ¹⁾ Seat belts were expensive so only luxury cars had them and most ordinary cars had them as option. And all cars capable to exceed 65mph were luxury cars. So today, it is the responsibility of the driver if he needs seat belts or not. People who use their classic cars on a regular basis usually have front seat belts either because the car was a luxury car anyway or they had retrofitted original belts matching the car. A classic car doesn't need seat belts in the rear since they are rarely used to transport passengers.
When my sister had married, I had restored a classic car of a friend, he paid the parts and material, my labour was for free. I've even made a replica of the bonnet to bolt the flour bouquet onto so the car could drive with normal speed. There were many reasons why I had picked this car. It was a very unusual car in terms of design and technology and my now brother-in-law loves powerful and good looking cars. It had an unusually powerful engine for that time which was also ultra-quiet. It had 3 times as much space in the rear as modern cars and it had no seat belts for the rear seats. In this case, seat belts would have been a restriction only

One of the rare exceptions are turn signals. They had to be retrofitted.
Originally, hand or flag signals were used. Hand signals became banned and then flag signals or electric turn signals were retrofitted.


en.wikipedia.org/wiki/Trafficators

Since 1963, flashing yellow turn signals are mandatory for all cars, no matter if they were already licensed or not. Since most of the flags had a bulb already, the flag signals are still legal if they have a bulb on the end which flashes and there are turn signal lights at the front and rear of the car. Most flags were removed and replaced by a stationary turn signal lights and an additional signal was installed on the rear bumper so the original flags are very rare. Cars with flags in the middle of the vehicle usually just had them deactivated so those cars still have them today and usually now reactivated as a legal additional turn signal. The bulb just needs to flash when the flag is out which isn't original but a good compromise.

For using original tires, I would need to ask an expert but I think that you could use them if you find tires which are licensed and less than 7 years old - using tires older than 7 years is illegal anyway. I have seen classic cars with tire replicas which are not licensed so they are only legal for classic car shows, not for public traffic usage.

-------------------------
¹⁾ The first documented car accident in my home town had happened (if I recall right) in 1906. Car accidents were just common accidents and there were no driver's licenses back then so car accidents were not recorded and there was no statistics.
There is a street called "An den 8 Bäumchen" ("Near the 8 little trees"). In this particular accident, one was destroyed. This had caused a lot of fuzz since the major had to decide if the street would have to be renamed or if they plant a new one.
They did plant a new one and today you can see 7 large ~130 years old trees with a small sick but still living tree which suffered in the shadows of the larger ones for well over 100 years.

the problem I have is that it has aftermarket wheel covers, which are not well designed. I could modify the wheel covers but since I also buy tires that don't lose air unless there is damage involved; it is not an issue for me.