KNOW YOUR PAYLOAD
Payload - what is it? The weight of equipment and personal possessions you can carry in your motorhome without overloading it
Why is it so important to understand Payload? Safety to avoid overloading components Legality Police and VOSA roadside checks Manufacturer s payload allowances are not always realistic for your needs So payload criteria is vital when choosing a motorhome and buying new kit
Motorhome payloads are covered by European standard BS EN 1646 part 2 There are two categories: Essential habitation equipment included in MRO User Payload the difference between MTPLM & MRO Note there are variations how different manufacturers use the standard
Certification If the manufacturer is a NCC member the motorhome will come with this certificate
Essential habitation equipment Recommended gas cylinders when filled Fresh water storage - 90% full Central heating systems full Toilet flushing tank full Toilet waste and grey water tank empty Electrical hook up cable 4kg Leisure battery All these items should be included in the manufacturer s stated MRO figure
Mass in Running Order - MRO Motorhome MRO includes: The unladen vehicle Engine coolants and oil Fuel 90% Spare wheel if fitted Driver 75kg Essential habitation equipment Note MRO can be subject to a +/- 5% tolerance Some manufacturers vary from the above
User payload is: The difference between MRO and MTPLM Where MRO is Mass in Running order and MTPLM is Maximum Technical Permissible Mass or GVW - Gross vehicle Weight or MAM - Maximum Authorised Mass
User payload will be reduced if the actual MRO exceeds the stated figure (remember the +/- 5% permitted tolerance) But an NCC approved motorhome is required to have an actual MRO which is equal to or less than MRO so no loss of payload Some imported motorhomes are accurate with their MRO figures others not so or they may quote a MRO figure with say the 100 litre water tank containing 20 litres and not 90 litres as per standard, thus reducing your available user payload.
User Payload is defined by European standard EN 1646 part 2 into three categories: Conventional load allowance for passengers standard 75kg (about 11.8 stone) for each person (driver s 75kg included in MRO) Personal effects - allowance for food, cutlery, pans levelling blocks, items personal to each occupant like clothing, cameras etc. To include for bikes, boats etc. calculated from a standard formula Optional equipment manufacturer s allowance for air con, bike racks etc NOTE THIS CAN BE ZERO
The Personal Effects Payload formula M = 10N + 10L N = number of passengers including driver L = overall length of motorhome Thus for a 2 berth, 6.3m motorhome personal effects are: (2x 10) + 63 kg = 83kg
Take a simple motorhome with good payload My 2 berth low profile Elddis Autoquest 140
2010 Autoquest 140 Spec Berths - 2No Length - 6.239m MRO - 2710kg MTPLM - 3300kg Hence maximum user payload is MTPLM MRO = 3300-2710 = 590kg
Breakdown of Autoquest payload This 590kg maximum user payload is made up of: Essential habitation equipment = 16kg (Elddis quote outside of MRO) Personal effects payload = 83kg (From the formula) Conventional payload = 75kg (One passenger) Optional equipment payload and high by normal standards) = 416kg (Arbitrary figure
But you need a little extra storage
Then you add a bike rack
A satellite system
An awning
Two Beeny Boxes
All my optional extras Manufacturer s Optional extras 20kg Satellite system 12kg Solar panel 9kg Pull out awning 40kg Two Beeny boxes incl contents say 60kg Engine soundproofing say 10kg Bike rack & 2 bikes* 35kg Total optional equipment fitted 186kg *Bikes are supposed to be included in personal effects but realistically it s best to allow for them in your optional extra allowance
Now see how my 2 berth Autoquest payload evaporates Optional equipment fitted as over Heavy duty battery weight over MRO allowance Driver weight over MRO allowance One passenger (75kg std allowance) Personal clothing, cooking kit, etc (assumed) Total Payload required Maximum Payload available 186kg 10kg 9kg 66kg 83kg 354kg 590kg
Spare payload of 236kg plenty for a couple of windbreaks on the back But watch the payload allowance of the rack My carrier has a limit of 35kg just enough for two bikes
Consider the same base vehicle with same body length - Autoquest 145-4 berth Additional equipment fitted as before Leisure battery (over MRO as before) Driver weight over MRO allowance One three passengers @75kg each Personal clothing etc (incr by 20kg) Total Payload required Total manufacturer s payload allowance 176kg 10kg 9kg 225kg 103kg 523kg 475kg* *Down from 590kg of 2 berth as MRO increased by weight of overcab bed and passenger seats with constant GVW
But consider the situation with a 6 berth motorhome in the same range 2 berth optional equipment payload 416kg 4 berth optional equipment payload 131kg 6 berth optional equipment payload 11kg Elddis and other helpful manufacturers include all this and other payload details in their brochures You need to check the payloads will meet your needs
So what do you do if you think you are putting on too much weight? Visit a public weighbridge fully laden including your fuel and water tanks full and normal number of passenger Minimum of two weighings - both axles together and then a single axle Tag axle units minimum of three weighings all axles and two axles singularly
Typical weighbridge certificate
Note your plated weights Gross vehicle weight Gross train weight Axle 1 front Axle 2 rear
Check you are reading the correct plate
Compare your weighbridge weights with your plated weights Location weighbridge reading Plated maximum Spare capacity GVW (both axles) 2920kg 3300kg 380kg Rear axle (RA) only 1540 kg 1900 360kg Front axle (GVW RA) 1380kg 1750 370kg Note the axle capacity exceeds the GVW
What if you are over your allowable gross weight? Courtesy of Watling Engineers
Remember The Road Traffic Act requires vehicle users to ensure that vehicles are not overloaded. If a vehicle is found to be overloaded the driver could be prosecuted or cautioned - fines of up to 5,000 for each offence. That means a fine for each overloaded axle plus any overloading on the total weight. If a vehicle is dangerously overloaded the driver could face a charge of Dangerous Driving which carries a maximum penalty of two years in prison. If a vehicle is overloaded and results in someone being killed the driver could face going to jail for Manslaughter or Death by Dangerous Driving.
One way out Remember the MRO includes for the weight of the water tank 90% full If you just stay of camping sites then you can travel with little or no water and use the payload freed up 90 litres of water weighs 90kg
Possible uprate? Air Suspension? Courtesy of Watling Engineers
Add on solutions are not the complete answer Suspension may be only one aspect of mechanical overloading Overloading is also a legal issue Even if the mechanical strength is upgraded, legally you are still restricted by your plated GVW & axle limits
The solution to the legal issue A company with specialist knowledge to check if your vehicle can be upgraded eg SV Tech in Leyland Where mechanical improvement is required such a company can advise and steer you through bureaucracy of DVLA to obtain a new recognised plated weight
Sometimes upgrading can cause other problems CI category enables you to drive a motorhome up to 7500kg GVW Most drivers have C1 category if they took their test before 1 st January 1997 Category B licence entitles you to drive a motorhome up to 3500kg only Since 1/01/1997 only a B category is given for a standard driving test Reach 70 years and you have to renew your licence - opt not to take a medical you lose the C1 category and left with category B
A familiar scenerio Weight at the rear end and a long overhang You may not end up like this but your rear axle is under strain Picture by Crazy Funny Photos
Overloading the rear axle is a common problem Courtesy of Watling Engineers, St Albans The further you extend the loading rear of the back axle the greater the loading on the axle Simple calculations need to be undertaken before carrying heavy loads to the rear specialist companies like Watling Engineers can help
Summary buying new Buyer beware Check there is sufficient payload for your needs including all passengers Check what kit is original spec (and included in MRO) and what comes out of your user payload Does the unit comply with EN 1646-2 the payload standard Check the MRO figure does include an allowance for material variation (+/- 5%) ie the actual MRO will not be above the stated figure
Summary buying second hand Buyer beware Ask to see specification details so you can answer the payload questions as for new units Where specification details are not available or a lot of extra equipment has been added ask for a recent weight certificate Check the plated GVW (MTPLM) and axle limits match the written specification
Summary Do check your fully loaded motorhome on a weighbridge Don t buy new kit unless you consider the payload consequences Remember it s not just the heavy 40kg awning, it s the accumulation of the extra few kg each season
Know your payload Thank you