GVW v Design Weight

GVW versus GDW

There are myriad different acronyms for gross axle weights, gross vehicle weights, train weights etc, and they can vary between manufacturers and indeed countries of manufacture.

Here are some examples;

GAW = Gross Axle Weight

MAW = Maximum Axle Weight

TAW = Total Axle Weight

PAW = Permitted Axle Weight

GVW = Gross Vehicle Weight

MVM = Maximum Vehicle Mass

PVW = Permitted Vehicle Weight

GTW = Gross Train Weight

MTW = Maximum Train Weight

PTW = Permitted Train Weight

I will put aside ‘Design’ weights for a moment.

Whichever way they are designated they all give the same information – the maximum legal carrying capacity for each axle, the maximum legal weight of the vehicle with a load imposed, and the maximum legal weight of the vehicle and associated trailer with a load imposed.

The plates generally list the weights in the ascending order of weight, first axle 1, then axle 2, then gross weight and finally train weight. The axle weights may be numbered 1 & 2, sometimes not.

In some examples there may not be a train weight, meaning that under C&U the vehicle was not designed with trailer towing capacity.

For example, a typical Class 7 plate

(1) 1650
(2) 2500
3500
5000

As previously discussed, the axle weights added together have a greater carrying capacity than the legal maximum weight of the vehicle. This is a built in tolerance to allow for uneven distribution of the load whilst the vehicle is loaded to its legal maximum weight. There is also a tolerance built in to the rear axle to allow for the ‘nose weight’ of a trailer which will obviously transmit some of its payload weight onto the vehicle through the towing hitch.

In 99% of the vehicles you will come across for test in Class 4 & 7 the weights can be considered as both the ‘Gross’ weight AND ‘Design’ weight.

So what about ‘Design’ weights?

Design weights really come in to play in the HGV world.

The UK and EU have set legal limits on maximum axle weights, maximum gross weights, and maximum train weights which cannot be exceed.

Maximum gross weights and maximum train weights are governed by the number of axles in a vehicle & trailer combination. One of the reasons for these weight limits is to limit the wear & tear on roads, bridges etc.

Each weight band has a different VED (Road Tax) band too.

For example,

A 2 axle rigid HGV can run at a maximum weight of 18000 kg

A 3 axle rigid HGV can run at a maximum weight of 26000 kg

A 4 axle rigid vehicle can run at a maximum of 32000 kg

The same weight, 32000 kg applies to a 2 axle artic & 2 axle trailer.

A 2 axle artic & 3 axle trailer can run at 38000 kg

A 3 axle artic & 3 axle trailer can run at 44000 kg

However, many of the major truck & trailer manufacturers have an interest in selling their product to as many customers as possible across both EU and non EU countries, where legislation over maximum weights can differ, so will often build them with a higher (DESIGN) axle and gross weight capacity.

So……..

Here’s an example of an the weights from a 4 axle Mercedes HGV

Axle 1 7100
Axle 2 7100
Axle 3 9500
Axle 4 9500

Gross 32000
Train 35500

However, the DESIGN weights (Manufactured spec) are higher,

Axle 1 7500
Axle 2 7500
Axle 3 10500
Axle 4 10500

Gross 34000
Train 37500

BUT the vehicle is only legally allowed to run in the UK & EU at pre-set weights. All newly registered UK HGV trucks and trailers are issued with a ‘Ministry Plate’ which lists UK maximum axle weights, gross weights, and train weights, and DESIGN axle weights, gross weights and train weights in two separate columns, which must be displayed on the vehicle.

Another example of gross versus design weights is where a haulier carries high volume but low weight loads.

Let’s take potato crisps for example. They come out of the factory packaged in boxes, but weigh very little. To maximise payload the haulier needs to get as many boxes on board as possible. He doesn’t need a truck with massive power & weight carrying capacity, so a 2 axle artic will do the job. He doesn’t need a 3 axle trailer with a high weight carrying capacity, so a 2 axle trailer will do the job.

Remember that the 2 + 2 can run at 32000 kg, but the payload of boxes of crisps weigh very little.

It’s common practice in this case to have the gross weight ‘downplated’ by DVSA to 26000.

The plate will again still show the original DESIGN weights as manufactured in one column, the UK legal axle weights will be shown in the second column along with the reduced gross weight. This allows the haulier to save money by dropping down the VED scale.

I hope that makes some kind of sense to you.