A significant proportion of commercial vehicle taxes are based on the load capacity of the vehicle. Truck & trailer manufacturers tend to big trucks to carry heavy loads and the basic vehicle taxes are correspondingly large. But there are some low density products ( e.g. Expanded Polystyrene packaging) where the manufacture needs a large truck or trailer but is only using a fraction of the vehicle's weight capacity. The down plating system allows the vehicle to be mechanically capable of carrying its original rated load, but it's "plated" value "Maximum Authorised Mass (MAM)" limits it to a smaller weight capacity. The reduction in its MAM allows it to be taxed at a lower rate. It might also mean the vehicle can be driven by a driver with a lower category of licence entitlements.
When a commercial vehicle is subjected to a roadside inspection, it's the "Plated" mass limit that is used as the weight limit. The Plate has to be displayed on the vehicle and it has meet regulatory requirement regarding its format and content.
Here is a guide just for information.
The Caravan industry and possibly other trailer manufacture's seem to have adopted a similar approach for domestic use. However the reasoning is not to reduce the vehicle tax burden as there is no change, but more as a marketing ploy to make their products more attractive to a wider range of drivers. I suspect the industry uses the" Maximum Technically Permissible Laden Mass (MTPLM)" as a descriptor rather than MAM is because their not sure it has the same legal standing as MAM
This could work in three ways:-
The caravanner finds a trailer with a an MTPLM of 1390kg. That gives a MAM+MTPLM of 3490kg.
The caravanner is stopped for a roadside check. The VOSA inspector may see the MTPLM sticker, but it does not conform to the legal requirements for the data it holds and goes on to find the finds the caravan's VIN plate where the MAM is stated to be 1450kg. that gives the Combined MAM 2100+1450 = 3550kg. The driver is not licenced to drive this outfit.
The caravan industry needs to get its act together about conformance with the existing regulations and either make sure upgrades are correctly addressed with conforming documentation and labeling.
And/or it should make lighter caravans and drop the down rating scheme and simply show the true MAM for the trailer.
When a commercial vehicle is subjected to a roadside inspection, it's the "Plated" mass limit that is used as the weight limit. The Plate has to be displayed on the vehicle and it has meet regulatory requirement regarding its format and content.
Here is a guide just for information.
The Caravan industry and possibly other trailer manufacture's seem to have adopted a similar approach for domestic use. However the reasoning is not to reduce the vehicle tax burden as there is no change, but more as a marketing ploy to make their products more attractive to a wider range of drivers. I suspect the industry uses the" Maximum Technically Permissible Laden Mass (MTPLM)" as a descriptor rather than MAM is because their not sure it has the same legal standing as MAM
This could work in three ways:-
Firstly Its a marketing ploy that can generate extra income if customers want to upgrade.
The second reason - which is the result of the industries own less than accurate advice, relates to the industry calculation of towing ratio's. By setting the MTPLM lower than the mechanical capability it again makes towing ratios look a little better widening the perception of acceptability.
Thirdly - for drivers who passed their test after 1st Jan 1997 who are limited to an outfit of combined MAM not exceeding 3500kg. Having a lower MTPLM on the trailer might bring a the combined MAM figure under 3500kg, where as without the down plating it might exceed the 3500kg limit and thus make the outfit illegal.
This last point might have a possible sting in the tail. Let us assume a caravanner has a tow vehicle with MAM of 2100kg THe driver does not have BE on the licence so is limited to a combined MAM of 3500kg. that leaves 3500-2100 = 1400kg for the MAM of the trailer.The caravanner finds a trailer with a an MTPLM of 1390kg. That gives a MAM+MTPLM of 3490kg.
The caravanner is stopped for a roadside check. The VOSA inspector may see the MTPLM sticker, but it does not conform to the legal requirements for the data it holds and goes on to find the finds the caravan's VIN plate where the MAM is stated to be 1450kg. that gives the Combined MAM 2100+1450 = 3550kg. The driver is not licenced to drive this outfit.
The caravan industry needs to get its act together about conformance with the existing regulations and either make sure upgrades are correctly addressed with conforming documentation and labeling.
And/or it should make lighter caravans and drop the down rating scheme and simply show the true MAM for the trailer.
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