There isn't one. So long as the weights on each axle/set of axles are legal, that's all Barney cares about.
In the UK, the maximum axle weight for a trailer axle on a 6 axle trailer is 8500 kg. In addition it must have road friendly suspension. With a 5 axle vehicle the maximum axle weight is 11.5 tonnes.
The Gross Vehicle Weight (GVW) of a vehicle/trailer is the total weight of a fully loaded vehicle/trailer with maximum number of passengers allowed, maximum number of cargo allowed, full tank of gas, etc that the vehicle should weigh at maximum.
The one difference between trailer and trailor is that trailor is not even a word. However, trailer is. A trailer is what you would call a mobile home.
there is no difference
You're talking about the trailer? Some specifics would be in order. On a tandem trailer, the axles are about three feet apart from each other. If you're referring to the distance between the trailer axles and the drive axles of the tractor, they're allowed to be a maximum of 41 feet apart, except in California, where they're only allowed a 40 ft. bridge between the two.
A typical tractor trailer or a straight truck is allowed 13' 6". A car hauler is allowed 14'.
The Maximum Weight varies with the size of the trailer. The Maximum Wait is a different matter.
The maximum distance allowed from the rear axle of a commercial vehicle trailer to the rear of the trailer can vary by jurisdiction. In the United States, for example, the Federal Highway Administration typically allows a maximum overhang of 4 feet beyond the rear axle for most trailers. However, specific regulations may differ by state, so it's essential to consult local laws for precise measurements. Always ensure compliance with both federal and state regulations for safe and legal operation.
Straight truck is a single vehicle; i.e., there isn't a trailer in tow.
Length does not determine whether or not a CDL is required.
The regulations for when a CDL is required has nothing to do with length.
Most trailers are semi trailers. You're probably asking the difference between a semi trailer and a full trailer. A semi trailer is not wholly self supporting, and weight is distributed both the trailer axles, and to the tow vehicle. A full trailer supports its own weight fully.