TIPS ON PURCHASING A MOTORHOME

I would strongly suggest that you weigh any motorhome that you are serious interested in buying before committing to the purchase. Weigh the complete motorhome, then the rear axle by itself, (front axle weight = total – rear axle) then compare those weights to the allowable maximums printed on the LAST manufacturer’s “stage” plate, ie the plate with the highest stage / stufe / étape number. Usually the axle ratings don’t change between plates, but can like the example below. The GVM often does, and the GCM often reduces.

Fiat First Stage rating plate. GVM = 3650 kg, GCM = 6150 kg. Axle 1 = 1850 kg, Axle 2 = 2000 kg
Stage 2 rating plate, which has the GVM increased to 3850 kg, GCM reduced to 5750 kg. Axle 1 increased to 1950 kg, Axle 2 remains at 2000 kg

GVM = Gross Vehicle Mass – ie the total the motorhome is allowed to weigh.
GCM = Gross Combination Mass – if towing a trailer, the maximum the motorhome plus trailer can weigh combined.

You will then need to make an allowance for all of the extra items you intend to carry. Don’t forget, anything placed towards the rear of the motorhome will add more than its own weight to the rear axle, eg can be up to an extra 70% for bikes mounted at the rear. ie 60kg of electric bikes mounted on a bike carrier can add 100 kg to the rear axle (the 40kg difference comes off the front axle). You can use my calculator to help determine approximate axle weights for items added to your motorhome.

In testing in Europe, over 50% of motorhomes have been found to be overweight, either GVM or over an allowable axle weight, or both!. I would suspect in NZ it would be closer to 75% for motorhomes with a GVM of less than 5000 kg. We like to travel prepared for anything!. Note, it is completely possible to be under GVM, but to be exceeding an allowable axle weight limit, especially on Fiat Ducato’s (and its Citroen / Peugeot siblings) as the rear axle weight limit on the “light” version is only 2000 kg. It’s also possible to exceed the rear axle weight limit on the “heavy” versions too of 2400/2500 kg.

A good rule of thumb as a starting point is to allow 200kg per berth for the occupant and their food, water, clothes etc. Then add the extras like bikes, sporting equipment etc

In my opinion no 6 berth motorhomes can legitimately be on a WOF because, based on the following calculation it’s just not possible to be under the legal maximum operating weight of 3500 kg. Making the assumption that the average weight of each occupant is 60kg, being a family of 6, 2 adults and four children of varying ages through to teenagers, so 6 x 60 = 360 kg. Subtracting the weight of the 6 occupants from the GVM of 3500 kg leaves 3140 kg for the motorhome, plus food, water, clothes and everything else you want to carry. Is there a 6 berth motorhome with an awning, satellite dish, TV, solar panels that weighs less than 3140 kg, and have spare weight capacity for necessities like food, water and clothes?

Similarly, for a 4 berth motorhome. Allowing for 4 occupants at 60 kg each = 240 kg. Now subtracting the weight of the 4 occupants from a GVM of 3500 kg leaves 3260 kg for the motorhome and everything we need and want to carry. If we allow 100 kg for 100 litres of water and we are left with 3160 kg. But still need to allow for LPG (20-40 kg), food & drink, clothes, linen, chairs, BBQ. Quite quickly this can add up to 160 kg or more, meaning the motorhome now has to weigh less than 3000 kg. A lot of 4 berth motorhomes have tare weights around this weight BUT without awnings, solar panels, satellite dish, TV which are typically to have fitted in New Zealand.

So in short, if the motorhome is a WOF, do the weight calculations carefully. Tare weights of around 3200 kg are common, which only allows 300 kg of “payload”. Being on a COF isn’t a instant fix either depending on the brand of base vehicle. “Light” Ducato’s often exceed their allowable rear axle weight of 2000 kg, even if they are under GVM …

If you find that the motorhome you have fallen in love with, will or likely have difficulty operating within legal maximums, check to see if the base vehicle is listed in my vehicle section. Many common European manufactured base vehicles can have their GVM’s increased by as much as 600+kgs and rear axle allowable weight limits increased by 200+kg too.

Eg. Fiat Ducato “light” variant, GVM from 3500 / 3650 kg increased up to 4000 kg, and rear axle from 2000 kg up to 2250kg. Fiat Ducato “heavy” variant, GVM from 3995+ kg increased up to 4800 kg, and rear axle from 2400+ kg up to 2700kg. Ford Transit FWD V363 (current shape), GVM of 3500 kg increased up to 4100 kg, with axle ratings typically remaining the same as they are already quite reasonable.

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