KERBWEIGHT ... ? Dont believe the manufacturer.

[Meister]

Hi all,

As I have mentioned somewhere in another thread, I recently bought a new car.

I needed to find the kerbweight in order to work out what I could tow to follow the 85% Guideline (not rule) as I am new to caravanning / towing and want to follow suggested best practise.

SO

I looked in the nice glossy sales brochure I received from the dealership and it stated 1489Kg for my model/spec.

I then looked in the owners manual which came with the car and IT stated 1564Kg for my model/spec.

I asked the dealership who stated the correct figure is the one in the handbook.

Now its not that I am the untrusting sort BUT ........

........ yesterday I took my car to a weighbridge and for the sum of £13 I have a printout which shows the kerbweight of my car (which includes 3/4 tank fuel and 1 person in accordance with EEC stuff) is actually ......

1580Kg.

So ....... 3 different weights to work from (all within manufacturers max limit):

Brochure Kerbweight: 1489 85%: 1265

Owners Manual Kerbweight: 1564 85%: 1329

Actual Kerbweight: 1580 85%; 1343

Seems that I can tow up to 78Kg more than I expected which probably gives me a wider range of vans to look at...... oh bliss lol.

Steve

 

[Val & Frank]

Meister,

Don't worry about it see the other thread, under Towing/Driving /Safety. Why don't we do it.

It would appear that the rest of the world (well europe ) do as they please. So all this 85 % guidance is not really worth anything these days.

Max tow limit, GTW are the new in bizz terms !!!!

Frank

 

[Lutz]

Kerbweight is specific to each car. Therefore, brochures, websites, databases, etc. can never be exact. For example, the towbar, which itself can weigh up to 40kg with all its fasteners, reinforcements, wiring harnesses, etc. is almost never included in any published data.

Look at it another way. If, for the sake of argument, the MTPLM of your caravan is 1300kg, then according to the brochure kerbweight, your weight ratio would be 87%, according to the owner's handbook 83% and according to actual measurement 82%. Is it really worth getting too excited about a range of 5%? I bet you wouldn't be able to tell the difference in the way the outfit handles, especially as you're probably very unlikely to tow in the condition which is specified for establishing weight ratios anyway (car in the lightest possible condition, caravan as heavy as possible).

 

[rob_jax]

Hi,

The kerb-weight can easily vary because of manufacturing differences, different options installed, even different brands of tyres or a stereo upgrade. And don't forget that the tow-bar and frame is a heavy lump of steel.

And the tolerance of the weigh-bridge will be in the region of 20kg.

No Frank, the German ADAC organisation researched what is required to safely tow a caravan at various speeds - hence the seven mandatory requirements for Tempo 100 - otherwise you can only tow at 80 kph.

The UK 85% guideline is a rule-of-thumb from anecdotal experience, but has no authoritative, well designed, independent testing to support it - unlike ADAC.

But in the end, the law in the UK is the same as the rest of Europe - the maximum braked trailer weight is the ultimate limit - and the 85% guideline or Tempo 100 are merely expressions of safe towing.

Robert

 

[Val & Frank]

Hi Rob,

I didn't mean to imply that continetal caravanners are unsafe.

Lutz had already pointed out that the German accident rate is no worse than the UK's. I think the continentals have it right and we in the UK have it wrong. As you say they carried out tests for the tempo 100.

Frank

 

[Meister]

Thanks for everyone's thoughts which I find interesting.

Incidentally my vehicle was weighed without a tow bar which is being fitted by the SEAT main dealer on Friday for what I believe to be a good price.

Removable tow bar with twin electrics

 

[clivea]

Hi Rob,

I didn't mean to imply that continetal caravanners are unsafe.

Lutz had already pointed out that the German accident rate is no worse than the UK's. I think the continentals have it right and we in the UK have it wrong. As you say they carried out tests for the tempo 100.

Frank

Hi, what is Tempo 100, I would be interested to find out as German safety standards are reckoned to be good.

Other Clive

 

[Lutz]

No, don't get me wrong. The 85% weight ratio is a good starting point but really a couple of percent either way is not going to make any difference. There is little point in religiously sticking to 85% as if it were written in stone.

 

[Meister]

Lutz,

Thanks for that and I take your point.

Steve

 

[Lutz]

ps: The 85% figure is purely arbitrary and convention. There is no evidence that would suggest that it is any more applicable than 80% or 90%.

 

[rob_jax]

Hi,

The Dutch ANWB did suggest a 75% match ratio, but this was based on actual car and caravan loading - as opposed to the UK favoured "novice" ratio of 85% based on kerb-weight and caravan MTPLM.

But since most people (in Holland and I guess the UK too) never bothered to weigh their car or caravan, and their data wasn't directly transferable in the same way as the kerb-weight / MTPLM information, ANWB dropped this advice some years ago.

However, the WhatTowCar web-site does use this ANWB match ratio calculation to give "stability" information - and includes your personal estimate for the car and caravan loads as part of the calculation. But then (unfortunately) compares their calculated ratio with the UK 85% guideline and not the original ANWB 75% guideline - which has the potential to mislead (a bit)

But as Lutz says, I doubt if people towing at 80% would notice a difference of 5% (if correctly distributed)

Summary? Asking the questions you did and taking steps to measure and correct (if necessary) means you've already started on the route to best practise - and so you shouldn't be one of those with stability issues on the road.

Robert

 

[KeithJ]

If I remember correctly the guideline was decided upon by the caravan club many years ago. I seem to remember it was 75%, then 80%, then 85%. I don't think it was too scientific but was merely revised to keep pace with practicality as caravans became more and more heavy. ...I must be getting old!

Keith J.

 

[clivea]

Hi, what is Tempo 100, I would be interested to find out as German safety standards are reckoned to be good.

Other Clive

 

[Lutz]

Tempo 100 is just a byname that everyone uses in Germany for the official process of getting 100km/h approval for towing trailers/caravans.

 

[rob_jax]

Other Clive,

If you want to read the ADAC summary of the requirements, take a look at:

http://www.adac.de/ReiseService/Camping/Camping_News/Meldungen/D_Tempo100.asp?ComponentID=3171&SourcePageID=8354
Obviously it is in German, but the seven bullet points are (could be?) quite easy to interpret even if you don't have any German - and if you open that page with an on-line translator then most provide a half reasonable translation.

Note: The last bullet point indicates that the trailer must have a stabilising coupling to ISO-11555 part 1 and then mentions the AL-KO and Winterhoff models - this is by way of example and not exclusive

I really enjoy the ADAC (and Dutch ANWB) web-sites - if you want an independent review on caravan tyres, or navigation systems, or caravans, or service centres - then I visit these sites (but you need membership to access many areas)

Robert

 

[clivea]

Other Clive,

If you want to read the ADAC summary of the requirements, take a look at:

http://www.adac.de/ReiseService/Camping/Camping_News/Meldungen/D_Tempo100.asp?ComponentID=3171&SourcePageID=8354
Obviously it is in German, but the seven bullet points are (could be?) quite easy to interpret even if you don't have any German - and if you open that page with an on-line translator then most provide a half reasonable translation.

Note: The last bullet point indicates that the trailer must have a stabilising coupling to ISO-11555 part 1 and then mentions the AL-KO and Winterhoff models - this is by way of example and not exclusive

I really enjoy the ADAC (and Dutch ANWB) web-sites - if you want an independent review on caravan tyres, or navigation systems, or caravans, or service centres - then I visit these sites (but you need membership to access many areas)

Robert

Rob,

thanks for the reply, I'll get the little lady on the translation

Other Clive