kerbweight confusion

bmwles
bmwles Forum Participant Posts: 14
edited December 2016 in Towcars & Towing #1

Hello I have a 2009 BMW 5 series 2.0d and have towed my previous van many times but have just bought another caravan but the specifications for the car state the kerbweight at 1575kgs which makes the caravan at 103% but I have been on the weighbridge at
work which is a VOSA site and the car weighs 1760kgs with a quarter tank and just me in the car that makes it 93% which is ok as I will never load the caravan up to the max weight. I am thinking of getting a Touareg which will tow anything but am reluctant
to change my BMW.

Has anyone  got any thoughts of towing at 103% or are these figures just guidelines

Comments

  • cyberyacht
    cyberyacht Forum Participant Posts: 10,218
    1000 Comments
    edited December 2016 #2

    The first two questions that spring to mind are 1. What is the towing limit for the car? and 2. What are your licence categories?

  • bmwles
    bmwles Forum Participant Posts: 14
    edited December 2016 #3

    Hi the towing weight for the car is 2000kg and I have had my licence since 1979 and also have full HGV entitlement and often drive 12 tons + so licence and experience is not a concern just at 103% will it be the tail wagging the dog and I rarely go over
    55 mph so just asking other caravanners for their thoughts  

  • Tigi
    Tigi Forum Participant Posts: 1,038
    500 Comments
    edited December 2016 #4

    Have a look at the Advice & Training section on this site which explains the weight considerations and limits. The kerbweight is as stated in your car specifications.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited December 2016 #5

    No wonder you are confused. Very few sources actually specify kerbweights in the way kerbweight is defined in UK legislation. Most treat kerbweight as if it were the same as the Mass in Service shown in the V5c (which it is not), again others take actual
    weighbridge readings without regard for any definition. So long as there is no agreement the sooner the notion of kerbweight is thrown by the board the better.

  • bmwles
    bmwles Forum Participant Posts: 14
    edited December 2016 #6

    Hi this is where I think we need a good set of rules,

    my van is 1630 gross and car is 1585 minimum kerb weight = 103%.    but my car is 2000 kgs  and the van is 1433 MRO which is 71%, but i have weighed my car and it is 1785 kgs but with a van  kerbweight of 1585kgsI am still only at 88.9%. so                                                                                                                                                                                                                                     

  • Chris Ardis
    Chris Ardis Forum Participant Posts: 55
    edited December 2016 #7

    The kerbweight shown by the manufacturer is usually fiction. There are a number of different meathods of calculating this weight for a start. Then the manufacturer only has to weigh one version of each car model. Usually the lightest to make it look good
    for the environmentalists.

    So the only real method is to take your car, after you've turfed out all the rubbish accumulated in it, to a weighbridge and find the true weight. Ideally with 90% full tank of fuel. Then add 70 Kg. for the hypothetical driver and you've got the real kerbweight.
    Then you can do the 85% car to caravan calculation properly.

     

  • tigerfish
    tigerfish Forum Participant Posts: 1,362
    1000 Comments
    edited December 2016 #8

    The current situationis really unaceptable. Once upon a time it was quite clear. The kerb weight of a car was as delivered from the manufacturer, it included all necessary lubricating oils and cooling water, but absolute minimum fuel in the tank.

    Then one manufacturer included a 2/3 full fuel tank and another included a driver.  Within a short time the whole thing had become confused and there was no standard that all could accept.

    We do need to pressurise the two main clubs into exerting  great pressure on the DfT to resolve this.

    TF

  • peegeenine
    peegeenine Forum Participant Posts: 548
    edited December 2016 #9

    I think we have the EU to blame for all this confusion.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited December 2016 #10

    The defintion of kerbweight is quite clear. It has always included a full tank of fuel. That's all covered by UK legislation. The real issue is that sources use the term kerbweight without sticking to the definition. Another issue is that kerbweight has never been documented anywhere and current regulations don't refer to the term kerbweight anyway. Really, kerbweight is an obsolete term, but everyone still uses it and usually in the wrong sense. A lot of confusion would be avoided if the term kerbweight were simply scrapped in line with current rules and regulations.

    I think we have the EU to blame for all this confusion.

    The EU has never used the term kerbweight so one cannot blame the EU.

  • Wildwood
    Wildwood Club Member Posts: 3,581 ✭✭✭✭
    1000 Comments Photogenic
    edited December 2016 #11

    The kerbweight shown by the manufacturer is usually fiction. There are a number of different meathods of calculating this weight for a start. Then the manufacturer only has to weigh one version of each car model. Usually the lightest to make it look good
    for the environmentalists.

    So the only real method is to take your car, after you've turfed out all the rubbish accumulated in it, to a weighbridge and find the true weight. Ideally with 90% full tank of fuel. Then add 70 Kg. for the hypothetical driver and you've got the real kerbweight.
    Then you can do the 85% car to caravan calculation properly.

     

    I would say 50% full in the tank although it is probably not crucial but on a journey the tank is full only at the start. The kerb weight figure includes 75kg for the driver so sit in it and get the true figure. You will also get the additional weight of
    the tow bar which might be more than you thought.

    The calculation is not possible from the manufacturers figures though as in most cases as individual cars are not weighed and they simply publish a figure for the basic car.

  • peegeenine
    peegeenine Forum Participant Posts: 548
    edited December 2016 #12

    If we hadn't joined the EU we would still have the UK kerbweight, GVW and GTW which we all understood, didn't we?

    MIRO, in my opinion has confused the UK understanding of Kerbweight. The recent changes to the way MIRO is now being quoted by manufacturers, especially motorhome manufacturers, is very misleading and irresponsible.

    It is very odd that kerbweight is still being refered to when matching car to caravan and agree that the term should have been dropped when MIRO came into being.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited December 2016 #13

    If we hadn't joined the EU we would still have the UK kerbweight, GVW and GTW which we all understood, didn't we?
    MIRO, in my opinion has confused the UK understanding of Kerbweight. The recent changes to the way MIRO is now being quoted by manufacturers, especially motorhome manufacturers, is very misleading and irresponsible.
    It is very odd that kerbweight is still being refered to when matching car to caravan and agree that the term should have been dropped when MIRO came into being.

    UK kerbweight still exists, but it's not and has never been documented anywhere and therefore no-one sticks to it. Instead, they use the term kerbweight, but actually mean something completely different.

    By the way, the MIRO, or mass in service as it's called in the V5c, is not the actual weight of the vehicle in question. It's not defined like that, but there again, many think it is. At worst, it's confused with kerbweight.

  • cyberyacht
    cyberyacht Forum Participant Posts: 10,218
    1000 Comments
    edited December 2016 #14

    All these different definitions don't stop my OH wailing when standing on the bathroom scales. Undecided

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited December 2016 #15

    It's quite easy really:

    Kerbweight is when she weighs herself after dinner with all her things on.

    Mass is service or mass in running order is what she weighs when she's had dinner but 10% less to drink than above, gone to the bathroom and about to go into the shower or have a bath.

    Unladen weight is the same as above but before having dinner.

    She can pick which one suits her best.

  • TimJim
    TimJim Forum Participant Posts: 162
    edited December 2016 #16

    Ha ha Lutz.......inspired succinct and very understandable !!.....

    Tj

  • Fozzie
    Fozzie Club Member Posts: 550
    500 Comments
    edited December 2016 #17

    Unfortunately this subject is very similar to explaining the offside rule in football.

    As a caravanner of 30 years,I have no idea now how to work out any safe towing limits.In my day it was an easy formula of 85% of kerbweight of tow vehicle relating to maximum weight of caravan,now with all the changes who knows.

    I am sure people now can adapt their figures to suit their needs.

    On this very site the Club have an advertising banner for a Ssang Yong stating can tow 2 tonnes.And that's the Club showing that advert.This on a vehicle weighing around 1600kg.

    Surely now there must be an easier and a safe way of having a tow match worked out which I can understand.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited December 2016 #18

    Because so many factors determine how safe a towing outfit is, weight ratios alone are not going to be the be-all and end-all, no matter how kerbweight is defined. The various definitions, be it kerbweight, mass in service, unladen weight, actual weight, etc. are not going to affect any calculated weight ratio by more than about 5% and that should be close enough for any decision one way or another. Whether the result is 85% or 90 % is not going to make a difference worth talking about. The only absolute limits are the legal ones.

  • Qashqai66
    Qashqai66 Forum Participant Posts: 551
    edited December 2016 #19

    It is all totally misleading.  When we are towing I am the driver.  My weight falls a very long way short of 70 kg of so that immediately knocks almost 20 kg off the kerb weight figure.  

  • Qashqai66
    Qashqai66 Forum Participant Posts: 551
    edited December 2016 #20

    And if kerb weight is meaningless can anyone tell me what formula to use in its place.  This concerns me as we are looking to change our car.

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
    1000 Comments
    edited December 2016 #21

    I wish I could say the same about my weight .....

     

    wouln't it be nice i I could have just commented about part of the quote instead of all of it!

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited December 2016 #22

    The legal definition of kerbweight doesn't include the driver so your own weight is irrelevant.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited December 2016 #23

    That's a question you need to ask the CC or other sources that continue to refer to kerbweight in their weight ratio recommendation.