Variations in quoted kerb weight

[tuffty]

Wondering if anyone could explain why there is such a variation in quoted kerbweight for the same car?

I'm looking at the newer S-Max mark 2 as a potential new tow car next year - I want 3 full seats in the middle and very few if any SUVs seem to give that. Having had an S-Max in the past they are a great car and the new model 2.0 AWD has 400 Nm of torque so perfect for towing duties.

However, looking at the PC review:

https://www.practicalcaravan.com/reviews/tow-car/43122-ford-s-max
The kerb weight is given as 1838 kg (doesn't specify whether that's the AWD or FWD model).

The honest john website lists it as 1857kg:

https://www.honestjohn.co.uk/specs/detail/?v=M108347
However when I go to Ford's own website and look at the S-Max brochure:

https://www.ford.co.uk/content/dam/guxeu/uk/documents/brochures/cars/BRO-SMAX.pdf
The 2.0 180 PS AWD model is the heaviest of the lot and is listed as 1809kg including driver at 75kg.

I realise we're talking a difference of 48 kg from bottom to top of the weight range quoted which isn't massive. Either way it's significantly heavier than my current BMW which tows just fine at 1705kg (caravan MTPLM is 1625kg), and as the S-Max has such a huge boot and the gross vehicle weight is 2615kg I'd be putting all the heavy stuff such as awning etc in the car anyway, so in practise the ratio would be fine. I guess I'm just curious really as to why it seems to be so difficult to get a reliable figure for the kerbweight of the car?

 

[ProfJohnL]

Hello Tuffty,

I cannot explain why different organisation will give teh same model of car a different kerbweight - you would have to ask them about their methods or source information.

What I can tell you is there is no legal requirement for manufacturers to quote a kerbweight, Some do Some don't, and becasue there is no regulation of the criteria for kerbweight the methods used by each organisation are inconsistent.

What is included in "Kerbweight" is not defined in law, so it is open to interpretation, However there is a gentleman's agreement which suggests it should include the total weight of a vehicle with standard equipment, all necessary operating consumables, a full tank of fuel, and just the driver with no luggage.

But not all manufacturers choose to follow this general pattern. Some choose 3/4 tank of fuel. some quote without the driver.. and so on. And some do not bother to quote it at all.

However the Type Approval process should produce "Mass in service" (MIS) which is defined under The European Directive 95/48/EC and includes 90% fuel and 75kg for driver and tools. The DVLA should use the same definition on the V5. It is generally assumed by most that kerb weight is the same. Its close but not exact, and the difference is most likely not significant in any legal importance.

Some manufacturers will get round the issue by producing the same handbook for a range of vehicles and suggesting the kerbewight should fall within a range of values.

It is always good practice to try and keep the weight of the caravan a small as possible in relation to the weight of the tow vehicle. Caravanners tend to want to know the Kerbweight so they can choose a suitable tow car or caravan based on the caravan industries guidance figure of 85% MTPLM/Kerbweight. But this is only guidance and is not any sort of guarantee of safety or good towing. However It is highly unlikely that an outfit would be great at 85% but dreadful at 86%, so there is some latitude but as previously suggested better to err on the low rather than the high side.

 

[tuffty]

Thanks for that, very useful! I didn't know there was not a single agreed definition. Must vary by manufacturer I guess as my current car, the V5 mass in service exactly matches the published kerb weight everywhere I've looked.
Anyway as you say, it's only a guideline!

 

[GeorgiePorgie]

Hi Tufty,

The only way you're going to get an accurate kerbside (unladen) weight of the car is to get it, fit your tow bar (if not factory fitted) remove all your odds & sods from the car, but keep in it the tools, spare wheel etc & a full tank of fuel, then find your local friendly weighbridge & weigh it, then add 75kg for you! job done!

My car's stated Mass in service is 1635kg, but it actually weighs 1720kg & my 75kg (I wish!!!) weight makes the kerb side weight 1795kg....some 160kg than stated! or if you prefer, as near as damn it 3.25 cwt (360lbs) in old money!

 

[ProfJohnL]

Hi Tufty,

The only way you're going to get an accurate kerbside (unladen) weight of the car is to get it, fit your tow bar (if not factory fitted) remove all your odds & sods from the car, but keep in it the tools, spare wheel etc & a full tank of fuel, then find your local friendly weighbridge & weigh it, then add 75kg for you! job done!

My car's stated Mass in service is 1635kg, but it actually weighs 1720kg & my 75kg (I wish!!!) weight makes the kerb side weight 1795kg....some 160kg than stated! or if you prefer, as near as damn it 3.25 cwt (360lbs) in old money!

Hello GeorgiePorgie.
I'm sorry to pursuing you through your other answers, but you have made a serious accusation about the accuracy of information I have provided about towing weights in another thread. Please respond to that thread and tell me where you find my advice in error.