Payload – What’s it all about?

It amazes me at times when I see campers offered for sale new from manufacturers with an advertised payload of around 200kgs.  I get frightened when I here owners asking on forums “what is payload” or “how do I know if I’m overweight”.   Then I see reports that VOSA carried out a routine spot check and found 83% of all motorhomes stopped were over weight.  All very scary stuff.

So what do we mean when we talk about payload?  Well in simple terms it is the difference between Mass in running order (used to be called curb weight ) and GVWR (gross vehicle weight rating) and is the maximum weight of the vehicle including all the extras and personal items.  Ok so lets look a bit deeper to try and understand what that means in simple terms.

Mass In Running Order (MIRO)  This is the empty weight of the camper with the following items included  –  a 75kg allowance for the driver plus engine coolants and 90% of the fuel tank, water tank and gas capacity.  This is probably the most underestimated area as many people will have added items prior to delivery and don’t take the additional weight into consideration, so they forget about adjusting the MIRO to account for any items fitted at the factory or dealer.  These are regarded as static items and cannot be easily removed and they come off the manufacturers advertised “payload”.

Maximum Technical Permissible Laden Mass  (Sometimes called GVWR) – this is the maximum weight of the vehicle when fully loaded.

So taking one from the other we arrive at the available payload.  GVWR – MIRO = Payload.

To work out how much weight (Payload) you have available before adding your own personal things you must find out the weight of all the items you added BEFORE leaving the dealer, such as awning, extra battery, upgraded engine, auto gearbox etc.   Usually manufacturers will publish the weight of their options and this should be used as a guideline.  This total weight (lets call it Adjusted MIRO) should be noted as you will refer to it throughout your ownership of your motorhome.  Take this figure away from the GVWR and this becomes the available payload you have to work with.

Next you need to add up the weight of all the items for your trip away, such as pots and pans, clothes, food, bikes, dogs and most importantly the wife and kids.   What I do is add in the essentials and then take the camper along to our local weighbridge and get a weight printout.   Its usually the small things that add up such as BBQ, table, recliners,bikes, books etc.  These can add up to several hundred kgs and when you add on solar panels, inverters, sat dish, TV microwave and toaster then you can begin to see the problem.  This can then be used for future trips as if the weight certificate shows I’m well under my limit then its hardly likely to change much over the coming trips.  If I’m at or over my limit then I need to comb through and remove any items that I hope I can manage without.  Unfortunately if you are in the category of near or over limit then more frequent trips to a weighbridge may be necessary.

Tip:  If you are near or over your limit then look at the amount of fresh water you are carrying and reduce that to a minimum for travelling.  Water weighs 1kg per litre.

Unfortunately that’s not the whole problem.  Every camper is issued with a weight plate, usually found riveted inside the habitation door or inside the bonnet.  This plate is very important and it gives the following information:








The first figure is:-

Max weight:                6000kg This is the maximum weight allowed with all items loaded.

Train Weight:            9000kg This is the maximum weight of the camper plus the trailer

Front Axle weight:    2300kg  This is the maximum weight that can be placed on the                                                 front axle.

Rear Axle(s) weight:  4650kg This is the maximum weight on the rear axle.  In the case                                             of Alko chassis were there can be two axles the weight is given                                                   for each axle individually and shown as 3 on the plate.

Not shown on this particular plate is the:-

Towing limit:               This is the maximum weight of a trailer that can be towed. This is either on the plate or written in the camper handbook.  The Train Weight limit is not necessarily the same weight as the Maximum Weight plus the Towing Weight,  Some chassis have a higher maximum towing weight limit than the difference between the Train Weight and maximum weight, however the Train Weight limit is the Legal Limit you should work to.  Does that make sense?

Note:  In almost all cases you will note that the sum of both front and rear axle maximum weights exceeds the maximum weight shown on the first line.  This does NOT mean you can load each axle to its maximum limit and be ok – The vehicle maximum limit is the one that applies

As you can see its not straight forward.  You can have an instance where the overall weight is within limits but one or the other axle can be overloaded.

Public Weighbridge:  Throughout the country there are hundreds of public weigh bridges and these are open to members of the public.  Owners of camper vans can take their campers to these weigh bridges and for around £5 can have them weighed.  The process is very simple.  You drive the front wheels on to the scales, stop and the operator signals once the axle weight has been recorded.  Then you drive on to the scales completely, stop, and the operator weighs the entire camper.  Once that has been recorded you drive forward until the front axle is off the scales and the rear axle remains.  This weight is recorded and you drive completely off.  The operator gives you the certificate.

Sadly that is not the end of the saga.  Your driving license comes into the equation.  Depending on when you passed your driving test will determine the maximum weight you are allowed to drive.  For full details consult the DVLA website.  Broadly speaking if you passed your motor car test before Jan 1997 then you are allowed to drive vehicles up to 7500kgs, however if you passed your car driving test after Jan 1997 then you are limited to 3500kgs.

I have been campaigning for some time now to introduce a voluntary code of practice whereby dealers issue every motorhome that leaves their forecourt with a weight certificate showing the adjusted MIRO and available payload for both new and secondhand campers.  This would really help new owners to better understand what payload they have to play with.  Remember Insurance companies will not pay out in the event of an accident if they discover that the policy holder has been driving their vehicles when overweight.    In the eyes of the Law, ignorance is no excuse.

Sadly all my efforts have fallen on deaf ears as all the dealers realise that to provide a weight certificate for every motorhome that leaves their premises would result in many lost sales as prospective owners would not buy many campers knowing they would be overweight.

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