So you’ve bought your brand new motorhome, and are already getting excited about where you are going to take it.

However, before you set off on your first tour in what you’ve chosen as the best motorhome for you, you need to work out just how much you can put both in and on it.

Well, that should be easy, shouldn’t it? All you need to know are your motorhome weights. You have the gross vehicle weight of the vehicle, or the Maximum Technically Permissible Laden Weight (MTPLM), to give the official terminology – and yes, that is a mouthful.

All you need to do is subtract the unladen weight – or Mass in Running Order (MiRO), to use another mouthful – and that gives you your payload. In other words, the amount of stuff you can load onto the vehicle legally. Simple, really.

However, spend a bit of time examining the technical details of your chosen motorhome in either a manufacturer’s brochure or on the website, and you might find that, when it comes to payload, things start to get a little bit more complicated, and that’s before we even consider motorhome upgrades.

Why? Well, to start with, what does that term ‘mass in running order’ actually mean? You might think it means the weight of the motorhome when it has just been delivered to the dealership, with virtually no miles on the clock, and no one in it. But would such a figure ever be realistic – or useful?

After all, in order to serve its proper function a motorhome needs to have at least two things in it: a driver, and some fuel in the tank. As soon as you add that, you are obviously adding weight – and thus lowering the payload.

That is why most manufacturers assume that certain things will need to be included when they calculate the weight of the ‘unladen’ vehicle. These numbers – which are included in the NCC’s (National Caravan Council’s) MiRO guidance figures.

While most manufacturers go down this route, some Continental brands also choose to include things such as operative fluids in the vehicle (lubricating grease, oils, coolants and so on). Others account for just one gas bottle, made of aluminium, and weighing either 16kg or 17kg. Minor differences, but they do add up.

And working out a realistic margin for payload doesn’t stop there. Take that allowance for a single driver, for example – it’s perhaps fair to say that most people will generally be travelling with more than one person on board the ’van.

Conventional Load

For that reason, when coming up with a realistic figure for payload, manufacturers also need to make an allowance for what is known as Conventional Load (CV). That means adding 75kg to the MiRO figure for every designated seat in the vehicle, excluding the driver.

That covers occupants – but what about their possessions? Here there is a more complicated formula known as the Habitation Payload (HP) that many manufacturers follow. This is calculated using the formula 10L + 10N, where L is the overall length of the vehicle and N is the number of designated travelling seats. So, for example, a 6.99m-long motorhome with four designated travelling seats would have an HP of 109.9.

In theory, a manufacturer would deduct these two figures – the CV and the HP – from the overall MTPLM, and then also subtract the MiRO figure to give them a rough idea of what the user payload will be. So, if our hypothetical 6.99m-long motorhome (see: the best motorhomes under 7m) has four travel seats and a MiRO of 2600kg, it will have a user payload of 565.1kg (3500-2600-225-109.9=565.1).

If you weren’t aware of this formula, that may not be entirely surprising – manufacturers are only obliged to quote the MiRO and MTPLM figures, and the weight on each axle.

Then the options

That’s not the end of the matter. Because, if you have been busy dreaming up what sort of kit your desired motorhome is going to have, it’s more than likely that you have ticked a few of the optional extras that the manufacturer may be offering you. While these obviously cost more money, they also add weight – which will in turn decrease your user payload further for when you’re loading your motorhome.

You’d be surprised how much weight some optional extras can add. We’ve included a sample of them below, as provided by the NCC.

Guidelines say MiRO should include:

• The mass of the fuel tank, when filled to 90% capacity
• 75kg to account for the weight of the driver
• The mass of any fresh water carried, as specified by the manufacturer (most manufacturers recommend you drive with no more than 20 litres in the tank, or 50 litres for larger vehicles)
• The mass of any recommended gas cylinders

Weight of typical optional extras

• Motorhome bike rack: 8kg
• Electric step: 5kg
• Flexible solar panel: 7kg
• Rigid solar panel: 11kg

• Towbar: 35kg
• Oven and grill: 13kg
• LPG tank (empty): 14kg
• Sidebars: 14kg
• Roof bed: 60kg

Don’t forget the weight that useful touring accessories such as the best portable power station can come to, either.

One optional extra not mentioned in this list – an automatic gearbox – can eat into your payload by as much as 50kg. This is one reason why some manufacturers state within their small print that if you go for an automatic gearbox you may have to reduce the number of permitted travel seats in your ’van, if you still want to get under the crucial 3500kg overall weight limit.

Alistair Briggs-Price, from Newark-based motorhome dealer SMC, says he often finds that customers are keen to add all kinds of extras to their desired motorhome without considering how much weight this might add. He says, “We often have to explain weights to them quite carefully. An automatic gearbox could put on an extra 50kg, Alde heating can put on 40kg, and a spare wheel another 40kg. You have to be careful with what you are adding.”

Some of the best motorhome manufacturers make this easier by providing a configurator that allows you to tot up not just the total cost of the extras you want, but their total weight as well.

One of these is Slovenian brand Adria. Gavin Cox, from Derbyshire-based Adria dealer Geoff Cox Leisure, thinks that this works well. “Now for the 2027 season we have a lot of detail for the base vehicle and then for each and every option. When we quote for a vehicle, it adds up all the weights and works out if it’s realistic; if not, it warns you or gives you the option of upgrading the payload.”

As an alternative to using apps, you could go for a model that already has the kit you want fitted, says Alistair Briggs-Price. “Calculating your payload is easier if you go for something like a Swift Voyager, say, or an Adria Matrix, or something like one of Pilote’s Evidence models,” he says. “They tend to have a ‘one size fits all’ approach to extras, so you know what you are getting.”

Some brands even now quote a figure for the total weight that would be taken up if you went for every option available.

Give or take

Even when you have totalled up the likely weight of your shiny new ’van, there is one more thing to consider. Motorhomes, after all, are made of materials that are not always going to be exactly the same weight. “We also have to factor in a 5% variance in weight which comes from the natural elements in the vehicle such as wood which can vary a little,” says Gavin Cox.

You’ll also want to consider how many people are likely to be travelling with you. After all, a good many adults weigh over 75kg (75kg is 11 stone 11 pounds). So if calculations are being made on the basis of 75kg per seat, the assumption must be that you will also be travelling with other people (children most likely) who weigh considerably less than this. If, however, you are travelling as a group of adults, you might need to adjust figures accordingly.

All of this applies to new models; if you are buying a used motorhome, payloads and weights can still be an issue, because previous owners are not always aware of how the vehicle’s weight may have been affected by extras they have added. This includes things they may have put on the motorhome, such as bike racks, ladders, a roll-out awning and more.

With any motorhome, you should always ensure that you are not running overweight by visiting a weighbridge. Don’t miss our tips on how to reduce the weight of your motorhome either, as we share some of the simple steps you can follow.

Getting uprated

So what is the answer to this when buying? Ideally you should have the motorhome weighed before you buy it, but if not, you should carefully check how the payload allowance has been calculated, and ensure that it is suitable for your needs.

If not, and you have the right driving licence (see: which driving licence do I need to drive a motorhome?), you can always see about having your motorhome upgraded.

Beth and Riki Hill motorhomers who run the Hills Explore YouTube channel, recently had their motorhome’s MTPLM uprated by having VB Air Suspension’s Semi Air system fitted, along with the same company’s Handling Package, which upgrades the front shock absorbers.

The cost of the actual uprating with VB is £375 for all vehicles. However, the cost of the system itself varies according to the size of the vehicle – and the Hills drive a big one. Their new system cost £5750 in total. It only increased MTPLM from 5000kg to 5500kg; but Ruth says that, particularly as they are full-time motorcaravanners, it was very much worth it. The extra margin (which apart from the 22kg of the new system itself, is entirely there for their own possessions) has given them huge peace of mind.

“We have cupboard and garage space to fill and maximise that additional payload! Plus we then had no concerns over travelling with passengers or water in the tanks when required,” she says.

Of course, the number of people old enough to have such a licence as standard is dwindling all the time, which is why manufacturers have been bringing out more and more models that weigh in at less than 3500kg. At the same time, we customers keep on demanding ever more extras with our motorhomes.

While such seemingly opposing interests continue, getting your payload right is likely to be an ongoing challenge.

Don’t miss what we have to say about how to maintain a motorhome’s cassette toilet, either, as we talk you through what is an essential, if unappealing, part of ‘van life.

Lead image: Philip Barker

Future Publishing Limited, the publisher of Practical Motorhome, provides the information in this article in good faith and makes no representation as to its completeness or accuracy. Individuals carrying out the instructions do so at their own risk and must exercise their independent judgement in determining the appropriateness of the advice to their circumstances. Individuals should take appropriate safety precautions and be aware of the risk of electrocution when dealing with electrical products. To the fullest extent permitted by law, neither Future nor its employees or agents shall have any liability in connection with the use of this information. Double check any warranty is not affected before proceeding.

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