Which weight to use to work out towing limit.

warthog
warthog Forum Participant Posts: 3
edited February 2016 in Towcars & Towing #1

HI, We have been caravanning for a number of years now and have recently upgraded to a heavier van. I passed my test post 1997 so am limited to the 3500kg limit. What I am finding particularly confusing is which weight i use to calculate what weight I'm
actually pulling. Do I use the kerb weight or the gross vehicle weight to add to the mtplm of the caravan? Can somebody please give me a definitive answer to this very confusing issue!!

 

 

Comments

  • Vulcan
    Vulcan Forum Participant Posts: 670
    edited February 2016 #2

    HI, We have been caravanning for a number of years now and have recently upgraded to a heavier van. I passed my test post 1997 so am limited to the 3500kg limit. What I am finding particularly confusing is which weight i use to calculate what weight I'm
    actually pulling. Do I use the kerb weight or the gross vehicle weight to add to the mtplm of the caravan? Can somebody please give me a definitive answer to this very confusing issue!!

     

     

    To tow over 750 kgs with a B licence you need to comply with these rules:-

    The plated MAM of the trailer must not be more than the UNLADEN/KERB weight of the towing vehicle


    The GVW of the towing vehicle plus the plated MAM of the trailer must not add up to more than 3500 kgs


    The ACTUAL weight of the empty trailer and its load must not be more than the listed towing capacity


  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #3

    To tow over 750 kgs with a B licence you need to comply with these rules:-
    The plated MAM of the trailer must not be more than the UNLADEN/KERB weight of the towing vehicle
    The GVW of the towing vehicle plus the plated MAM of the trailer must not add up to more than 3500 kgs
    The ACTUAL weight of the empty trailer and its load must not be more than the listed towing capacity

    A couple of errors there-

    For a start, there is no requirement any more that the plated MAM of the trailer must not exceed the unladen or the kerbweight of the towing vehicle. That requirement was dropped in 2013.

    Secondly, that the actual weight of the trailer must not exceed the listed towing capacity is not a legal requirement. However, exceeding it would affect warranty coverage. Besides, it's not the total weight of the trailer that counts when comparing with towing capacity but only its axle load, because the car is only towing the axle load, not the trailer's total weight. It is carrying, but not towing the rest (the noseweight).

    What was missing, however, was that the actual total weight of the outfit must not exceed the plated gross train weight.

  • Vulcan
    Vulcan Forum Participant Posts: 670
    edited February 2016 #4

    Quite correct Lutz, must update my info.

  • warthog
    warthog Forum Participant Posts: 3
    edited February 2016 #5

    Thanks for the replies.So i need to work on the gross vehicle weight,looks like the wifes towing then...!!

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #6

    To tow over 750 kgs with a B licence you need to comply with these rules:-

    The plated MAM of the trailer must not be more than the UNLADEN/KERB weight of the towing vehicle


    The GVW of the towing vehicle plus the plated MAM of the trailer must not add up to more than 3500 kgs


    The ACTUAL weight of the empty trailer and its load must not be more than the listed towing capacity

     

    Secondly, that the actual weight of the trailer must not exceed the listed towing capacity is not a legal requirement. 

     

    It is, because they're very clever in using the term MAM, Maximum Authorised Mass.



    So to put an empty trailer weighing 1000kg with a MAM of 2500kg on the back of my Passat with a trailer MAM of 1600kg would still be illegal. Because the trailers Authorised Mass is more than the cars Authorised Mass 

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #7

    It is, because they're very clever in using the term MAM, Maximum Authorised Mass.



    So to put an empty trailer weighing 1000kg with a MAM of 2500kg on the back of my Passat with a trailer MAM of 1600kg would still be illegal. Because the trailers Authorised Mass is more than the cars Authorised Mass 

    I think you'd be pushed to find any reference in legislation that would confirm what you have stated. The vehicle manufacturer only has an obligation to specify the 'towable mass', not the MAM of the trailer.

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #8

    Well, every car i've dealt with says "MAM" and it's right there, Max AUTHORISED Mass of a trailer. Not something like "Whatever it weighs at the time" like you suggest. 



    But right there, you've contradicted the old line you use about trailer axle weight by saying "Towable Mass". Which is, the whole trailer, not just whatever the axle weighs ;)

  • Wildwood
    Wildwood Club Member Posts: 3,582 ✭✭✭✭
    1000 Comments Photogenic
    edited February 2016 #9

    I think they use the GVW of the vehicle and MAM of the trailer rather than the actual weights as after an accident proving this had been exceeded on actual weights would be near impossible. The maximum figures give an easy level at which you are under or
    over for prosecution purposes.

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

    Well, every car i've dealt with says "MAM" and it's right there, Max AUTHORISED Mass of a trailer. Not something like "Whatever it weighs at the time" like you suggest. 

    But right there, you've contradicted the old line you use about trailer axle weight by saying "Towable Mass". Which is, the whole trailer, not just whatever the axle weighs ;)

    The car, of course, has its MAM, but for towing purposes, as far as the car is concerned, the MAM of the trailer is irrelevant. All that is important is that the MAM of the car and its gross train weight are not exceeded (and obviously the maximum permissible axle loads).

    The MAM of the trailer must not be exceeded either, but that is totally independent of what is allowed for the car.

    The 'towable mass' is not the total weight of the trailer. It is defined as its axle load because the car is not towing the the total weight of the trailer. It is carrying, not towing, that part which we normally refer to as the noseweight.

    I think they use the GVW of the vehicle and MAM of the trailer rather than the actual weights as after an accident proving this had been exceeded on actual weights would be near impossible. The maximum figures give an easy level at which you are under or over for prosecution purposes.

    Without actually weighing the outfit, the plated GVW of the car and the MAM of the trailer are only important as far as driving licence entitlement is concerned, not for what is technically allowable without regard for the driving licence.

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #11

    Cool You really do make it as you go don't ya! lol

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #12

    Cool You really do make it as you go don't ya! lol

    In what respect? Perhaps you might like to point out where any of my statements do not agree with the wording of legislation, if possible with references to the respective acts and/or statutory instruments. I am not aware of any conflict anywhere and I have read most of them.

  • Woody19
    Woody19 Forum Participant Posts: 43
    edited February 2016 #13

    Its much easier than that. Look on the passenger door pillar and you will find the plate. Subtract the smaller weight (second line) from the larger weight (first line) and you have the maximum trailer weight for that vehicle. The MAM for the caravan must not exceed this weight, and the first line plus the MAM of the caravan must not exceed 3500Kg.

    Once you have got that sorted don't forget to ensure that the noseweight of the caravan does not exceed the capacity of the car or the capacity of the towbar, whichever is the least. You'd be surprised how low the car cabaility is sometimes - many are only 80Kg, some are significantly less.

    Our last Passat had a Thule bar with removeable hitch; the Passat was (and still is) rated 90Kg, but the bar was only 85Kg so that was the figure. With our latest Passat we have the Westfalia that is also used as the factory-fit option, and that is rated 90Kg.

    Simples. Cool

  • Wildwood
    Wildwood Club Member Posts: 3,582 ✭✭✭✭
    1000 Comments Photogenic
    edited February 2016 #14

    Its much easier than that. Look on the passenger door pillar and you will find the plate. Subtract the smaller weight (second line) from the larger weight (first line) and you have the maximum trailer weight for that vehicle. The MAM for the caravan must
    not exceed this weight, and the first line plus the MAM of the caravan must not exceed 3500Kg.

    Once you have got that sorted don't forget to ensure that the noseweight of the caravan does not exceed the capacity of the car or the capacity of the towbar, whichever is the least. You'd be surprised how low the car cabaility is sometimes - many are only
    80Kg, some are significantly less.

    Our last Passat had a Thule bar with removeable hitch; the Passat was (and still is) rated 90Kg, but the bar was only 85Kg so that was the figure. With our latest Passat we have the Westfalia that is also used as the factory-fit option, and that is rated
    90Kg.

    Simples. Cool

    . There are some cars where the towing limit is higher than the difference between the cars maximum weight and the gross train weight so you have a choice of ext

    ra weight in the car or caravan but it makes getting the weights right difficult.

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

    Its much easier than that. Look on the passenger door pillar and you will find the plate. Subtract the smaller weight (second line) from the larger weight (first line) and you have the maximum trailer weight for that vehicle. The MAM for the caravan must
    not exceed this weight, and the first line plus the MAM of the caravan must not exceed 3500Kg.

    If you don't make full use of the MAM of the towcar, you can legally tow more than the difference between the plated gross train weight and the towcar's MAM so long as the gross train weight is not exceeded. Such practice may affect warranty coverage, but
    it is not illegal.

    Besides, as I have pointed out on a number of occasions, the difference between the gross train weight and the MAM of the towcar does NOT equate to the MAM of the trailer, but only its maximum permissible axle load.

  • IanBHawkes
    IanBHawkes Forum Participant Posts: 212
    100 Comments
    edited February 2016 #16

    How has the weight on the towball got anything to do with things? That is just complicating everything. I use the GVW of the car and the GVW of the van and add them together and that should be no more than your GTW.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #17

    How has the weight on the towball got anything to do with things? That is just complicating everything. I use the GVW of the car and the GVW of the van and add them together and that should be no more than your GTW.

    Add the GVW of the car to the GVW of the van (assuming both are at their respective limits) and you would exceed the GTW by the amount of the noseweight.

  • Chestrefeldian
    Chestrefeldian Forum Participant Posts: 53
    edited February 2016 #18

    Wouldn't the weight on the towball be included in the GVW, similarly any load on the roof? ... or am I mising something?

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #19

    Wouldn't the weight on the towball be included in the GVW, similarly any load on the roof? ... or am I mising something?

    Absolutely, yes. What I basically meant to say was that if the car is loaded up to its GVW solo, it will be overweight by the amount of the noseweight once the caravan is hitched up.

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #20

    The burden of proof is on the person making the claim, so crack on. Show me where it says that the trailers axle weight is the only thing that matters?



    Because this website, just so happens to be the gov one, and it says trailer weight:

    https://www.gov.uk/towing-with-car/driving-licence-rules-and-what-you-can-tow



    which to me, is the whole weight of the trailer! Not it axle minus nose weight. 



    Then you say you can exceed the cars towing MAM as long as the train weight is not exceeded.



    Not true, it's MAM, it's right there "AUTHORISED". Even if your car is totally empty bar the driver, it's still only authorised for a trailer of XXXXkg, you can't just add bits on because the towing vehicle is empty!



    What you're effectivly saying is if you buy a small car derived van that weighs 1000kg with a payload of 500kg, that has a towing limit of 600kg, and a gross train weight somewhere around 2100kg, you can actually tow 1100kg as long as the van is empty? 



    have a word with ya self! 



    I do hope no one takes your advice because you're gonna get someone in a lot of trouble one day! 

     

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #21

    The burden of proof is on the person making the claim, so crack on. Show me where it says that the trailers axle weight is the only thing that matters?

    Because this website, just so happens to be the gov one, and it says trailer weight:
    https://www.gov.uk/towing-with-car/driving-licence-rules-and-what-you-can-tow

    which to me, is the whole weight of the trailer! Not it axle minus nose weight. 

    Then you say you can exceed the cars towing MAM as long as the train weight is not exceeded.

    Not true, it's MAM, it's right there "AUTHORISED". Even if your car is totally empty bar the driver, it's still only authorised for a trailer of XXXXkg, you can't just add bits on because the towing vehicle is empty!

    What you're effectivly saying is if you buy a small car derived van that weighs 1000kg with a payload of 500kg, that has a towing limit of 600kg, and a gross train weight somewhere around 2100kg, you can actually tow 1100kg as long as the van is empty? 

    have a word with ya self! 

    I do hope no one takes your advice because you're gonna get someone in a lot of trouble one day! 
     

    You have confused what one is entitled to tow according to driving licence regulations, in particular in the case of a Category B licence, with what is technically allowable if one has a driving licence that is not similarly restricted, such as a B+E licence, for example. Nowhere in the link that you supplied does it say that the towing weight is equal to the total weight of the trailer. If you read legislation you will see that it says, quote,

    "Towable mass" means the mass of the trailer towed excluding the vertical load on the coupling point of the towing vehicle.

    Is not the 'vertical load on the coupling point of the towing vehicle' that what we generally call the noseweight?. Therefore, subtracting the noseweight from the 'mass of the trailer' one inevitably arrives at the axle load.

    If you can point out where exceeding the towload limit, as specified by the car manufacturer, is an offence so long as all the plated weight limits are not exceeded, you've obviously found a piece of legislation that has yet to be published.

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #22

    I didn't use that link in reference to the licence, i used it for the wording, the fact the gov website says "trailer weight" nothing about towable mass. You've given a quote, great, now reference it!.... 

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #23

    and I never said anything about exceeding towball limit.



    But now you mention it, along with licence requirements, yes! It's very interesting because you're effectivly saying that someone with a "B" licence can driver a vehicle with a gross weight of 3500kg and pull a 1000kg trailer and not a 750kg trailer as the
    law says.By simply banging the nose weight upto 250kg, meaning the trailer only appears to be 750kg on the axle.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #24

    I didn't use that link in reference to the licence, i used it for the wording, the fact the gov website says "trailer weight" nothing about towable mass. You've given a quote, great, now reference it!.... 

    The Road Vehicles (Approval) Regulations 2009, Schedule 5, Part 2, Section 1, Item 44

    and I never said anything about exceeding towball limit.

    But now you mention it, along with licence requirements, yes! It's very interesting because you're effectivly saying that someone with a "B" licence can driver a vehicle with a gross weight of 3500kg and pull a 1000kg trailer and not a 750kg trailer as the law says.By simply banging the nose weight upto 250kg, meaning the trailer only appears to be 750kg on the axle.

    Noseweight is irrelevant for driving licence purposes. Only the plated limits apply. However, as far as vehicle Construction and Use Regulations are concerned, actual measured values apply and these will be checked against the plated limits. The gross vehicle weight is the sum of the vehicle's actual front and rear axle loads and the gross train weight is the sum of all axle loads, including those of the trailer. The difference between the two is the axle load of the trailer.

  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #25

    ps: Only when referencing driving licence restrictions does the gov website use the term 'trailer weight'. In all other cases it talks about towing weight, which is something different.

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #26

    "The gross vehicle weight is the sum of the vehicle's actual front and rear axle loads"



    Except it's not! Often the sum of the axle weights (infact almost always) will equal more than the GVW 

     

  • Danny and Karen
    Danny and Karen Forum Participant Posts: 67
    edited February 2016 #27

    I didn't use that link in reference to the licence, i used it for the wording, the fact the gov website says "trailer weight" nothing about towable mass. You've given a quote, great, now reference it!.... 

    The Road Vehicles (Approval) Regulations 2009, Schedule 5, Part 2, Section 1, Item 44and I never said anything about exceeding towball limit.

    Just looked it up, it's about wheelchairs Cool



  • Lutz
    Lutz Forum Participant Posts: 1,564 ✭✭✭✭
    edited February 2016 #28

    "The gross vehicle weight is the sum of the vehicle's actual front and rear axle loads"

    Except it's not! Often the sum of the axle weights (infact almost always) will equal more than the GVW

    We're talking about actual figures here, not limits, in which case it is the sum.

    Just looked it up, it's about wheelchairs Cool

    I suggest you read the requirements of the reference that I supplied not just the column on the right listing the exemptions and modifications.