sheffcortinacentre Posted March 14 Posted March 14 How come a 4x4 sierra Monocoque can tow way less than a lada niva or jeep Cherokee both also monocoques? Yet a land/range rover Hilux can to a lot more . As I've seen arguments that a Monocoque can tow less than an equivalent vehicle with a separate chassis yet as my first line the sierra/ niva are similar spec? & That 2 & 4 WD is a factor? How is the towing limit of a vehicle arrived at? I presume there must be a formula/regs etc that manufacturers have to follow?
leakingstrut Posted March 14 Posted March 14 I remembered this from an another forum many moons ago and managed to find it on google... It's even more impressive if you recognise where the photo was taken.
LightBulbFun Posted March 14 Posted March 14 On 14/03/2025 at 13:51, Talbot said: This is wrong. The only thing that matters is the GVW and GTW. If your car is at 2200kg weight and has a GTW of 4300kg, then the trailer can be 2100kg and you are within your weights. Weight that the car is below it's GVW can be traded for trailer weight, as long as you stay within your GTW. There is wrong information about this all over the internet. Many people insist (in line with what you've said) that you can't tow more than (GTW-GVW) which simply isn't true. My W210 for instance is 2310kg GVW and 4410kg GTW. If the car weighs 1800kg with me and a bit of fuel in it, then I can tow 2600kg. And have. If it's loaded up to max weight at 2310kg, I can then only tow 2100kg. Expand On 14/03/2025 at 19:31, Faker said: Hi talbot. Not going to get in to a mud slinging war here chief… but I work in enforcement. You can not increase the towing limit of a vehicle by taking advantage of the tow car being lighter than its permitted maximum weight. I will produce the legislation for you to view. Your Mercedes w210 most definitely has a towing capacity limit of 2100kg. Expand as someone who lives for this sort of stuff, i'd be quite interested in seeing that this is what the government has to say about it on their general towing with a car page, simply that the max train weight must not be exceeded, theres nothing in there that says the trailer cannot weigh more then the the towing car itself, so as far as I understand it, what talbot is saying is correct as long as none of the plated weights of the car are exceeded (ie GTW and axle loadings) then as long as the vehicles plate does not explicitly state otherwise, the trailer can weigh more then the vehicle another bit of legislation im looking for if you have it to hand is, what *exactly* are the rules for vehicles before 1998 that are not plated with any weights? for example I doubt this 1930's Bentley has "towing weights" on its chassis plate but obviously I know you can tow with your 1930's if you wanted to (as I understand its only from 1998 onwards that the vehicle must be type approved for towing, if you want tow with it) so say for example @HMC wanted to buy a Caravan to tow with his Austin 12, whats the heaviest/biggest Caravan he could legally tow with it?
sheffcortinacentre Posted March 14 Posted March 14 I was led to believe when unknown your not supposed to exceed the tow vehicles weight IE a cortina weighs roughly a 1000kg so I've always stuck to that as only very late mk4's & mk5's have it on the I'd plt .but I think there rated at 1100 kg.
High Jetter Posted March 14 Posted March 14 On 14/03/2025 at 20:58, leakingstrut said: I remembered this from an another forum many moons ago and managed to find it on google... It's even more impressive if you recognise where the photo was taken. Expand A swollen Thames Trader in Ireland?
leakingstrut Posted March 14 Posted March 14 On 14/03/2025 at 22:48, High Jetter said: A swollen Thames Trader in Ireland? Expand On the way way back down the hill after climbing Soutra.
Faker Posted March 14 Posted March 14 On 14/03/2025 at 19:56, sheffcortinacentre said: How come a 4x4 sierra Monocoque can tow way less than a lada niva or jeep Cherokee both also monocoques? Yet a land/range rover Hilux can to a lot more . As I've seen arguments that a Monocoque can tow less than an equivalent vehicle with a separate chassis yet as my first line the sierra/ niva are similar spec? & That 2 & 4 WD is a factor? How is the towing limit of a vehicle arrived at? I presume there must be a formula/regs etc that manufacturers have to follow? Expand The vehicles with separate chassis tend to have a much stronger chassis, to which the tow bar assembly is usually attached, and a much stronger setup. The sierra typically has the towbar bolted through the boot floor, and as such it is quite restrictive as to the loads it can pull. Modern day monocoque cars tend to have towbars that mount directly in place of the bumper reinforcement bar!
sheffcortinacentre Posted March 15 Posted March 15 On 14/03/2025 at 22:48, High Jetter said: A swollen Thames Trader in Ireland? Expand Trader is the lorry . That's a 400e 12-15 cwt. High Jetter 1
Faker Posted March 15 Posted March 15 On 14/03/2025 at 21:45, LightBulbFun said: theres nothing in there that says the trailer cannot weigh more then the the towing car itself, so as far as I understand it, what talbot is saying is correct as long as none of the plated weights of the car are exceeded (ie GTW and axle loadings) then as long as the vehicles plate does not explicitly state otherwise, the trailer can weigh more then the vehicle Expand So… there has always been guidance or guidelines that recommend that the towed implement should not have weight more than the towing vehicle… rf reasonable to tow up to a vehicles designed limits. What Talbot is saying is… you can tow more than what is stated as the vehicles towing capacity limit, so long as you don’t exceed the overall gross train weight…. Which is incorrect
Faker Posted March 15 Posted March 15 Let’s look at talbot’s example with a different vehicle 2010 Land Rover defender. Has a documented 3.5t towing capacity The 2010 defender has a gross train weight of 6.3 to 6.7 ton, depending on the model. For this example we will use the lightest - 6.3t, which still has a towing capacity of 3.5t the 2010 defender has an unladen weight of 1815kg. 1815kg + 3.5t = 5.3t 6.3t GTW minus 5.3t leaves 1t spare so to speak, as the full potential maximum weight for the defender isn’t being used. Talbot is saying that you can tow more than what’s provided or documented as the maximum towing capacity, so long as you don’t exceed the GTW. In theory tow more than the 3.5t limit as there’s available weigh from the somewhat unladen defender. That’s simply not true. YOU CAN NOT exceed the maximum documented towing capacity of a vehicle as per manufacturer determination, regardless of what the GTW is.
LightBulbFun Posted March 15 Posted March 15 On 15/03/2025 at 01:25, Faker said: YOU CAN NOT exceed the maximum documented towing capacity of a vehicle as per manufacturer determination, regardless of what the GTW is. Expand yeah I get that part if theres a plate on the vehicle that says "do not tow more than 2000 kg" then yeah I get that, *but* if a vehicles *does not* have such a statement then as far as I understand it, as long as you dont exceed the max train weight and axle weight the vehicle is rated for, the trailer can be any weight so to speak to use your example does it say on its ratings plate that it can only tow up to 2000kg? On 12/03/2025 at 21:39, Faker said: Hi Talbot. This is largely correct to a certain degree… I have an ix35 with a kerb weight of 1675. With 5 people and some luggage, it can have a gross weight of 2300kg. Now it has a GTW of 4300kg… meaning with a full compliment of occupants it can still legally tow 2000kg on a braked trailer. Now whether the tow car is empty, or full to the gills… it can only ever tow up to 2000kg. The plated towing limits never change. Expand or does it just say that its max train weight is 4300kg? as I think there is an important distinction to be made there
Faker Posted March 15 Posted March 15 I do understand how this is confusing… but it is a fact that you subtract the maximum allowed mass or Gross Vehicle Weight for the tow vehicle, from the gross train weight, to get the maximum towing capacity. It really is that simple.
LightBulbFun Posted March 15 Posted March 15 On 15/03/2025 at 01:43, Faker said: I do understand how this is confusing… but it is a fact that you subtract the maximum allowed mass or Gross Vehicle Weight for the tow vehicle, from the gross train weight, to get the maximum towing capacity. It really is that simple. Expand but whats the source for that?, can you link me to the relevant legislation at https://www.legislation.gov.uk that states that "this is how the max towing weight of a vehicle is calculated" as I understand it "gross" in this context, (ie gross Vehicle weight, or gross train weight) is when something is laden, so gross train weight GTW, means that the whole combination of vehicle+trailer cannot be laden to a total weight more then that stated figure, (and gross vehicle weight, means that the vehicle itself cannot be laden such that its total weight is beyond xxx stated figure) but nowhere do I see in that or anywhere else does it state *how* the Gross train weight can be achieved again if the vehicle does explicitly ave a max trailer weight rating, im not disputing that, if @Talbot's Mercedes says in its handbook or on its VIN plate that "maximum braked trailer weight 2100kg" then im not going to say it can tow more then that, but otherwise if the only figures given is the GVW and GTW, then I cant see how the trailer itself is limited in weight, unless there is some specific legislation that states otherwise? and I am still wondering how the weight limits work for pre 1998 vehicles, On 14/03/2025 at 22:11, sheffcortinacentre said: I was led to believe when unknown your not supposed to exceed the tow vehicles weight IE a cortina weighs roughly a 1000kg so I've always stuck to that as only very late mk4's & mk5's have it on the I'd plt .but I think there rated at 1100 kg. Expand see thats kind of what I have been thinking, but I realise I am not sure I have ever actually read that in any legislation or the such like, so I would like to try and see if I can find it or whatever the actual rules are, written in law so to speak
EyesWeldedShut Posted March 15 Posted March 15 On 14/03/2025 at 19:56, sheffcortinacentre said: How is the towing limit of a vehicle arrived at? Expand On 15/03/2025 at 03:55, LightBulbFun said: but nowhere do I see in that or anywhere else does it state *how* the Gross train weight can be achieved Expand Someplace in the dark reaches of my mind I remembered reading some article that involved multiple hill starts but buggered if I can find that - did find the EU rules (and I'm assuming our post-Brexit ones will be the same but I cannot find any UK rules) The regs from 3.1.1.1 onwards (link below) cover it. I'm assuming that this is all done by the manufacturers these days but I seem to think that (once upon a time) it was done by the Road Transport Laboratory in the UK? So the 'proper' 4x4 can be shoved into low ratio and tug 3.5 tonnes up the hill start test - that's also the max permissible under the regs so that's where they get 3.5 tonnes from - no point in burning a clutch out to test 4.0 tonnes. GTW is what it is - the vehicle gets a tow weight calculated and then they plate it up by adding that to the GVW/MAM (see Reg 4 in the link) - there's not usually a trailer weight on the chassis plate, that just gets worked out backwards by GTW minus GVW e.g. my 3.5 tonne boxer van had a GTW of 6 tonnes and GVW of 3.5 tonnes = 2.5 tonnes towing possible - nowhere on the plate is that 2.5 tonnes listed, it's mental arithmetic I have uprated that to a 4090kg HGV but the train weight is unchanged so the max tow weight is now 1910kg. (new plate shows 4090kg and 6000kg) No idea about the older stuff - my 1983 RR was plated at 3.5 tonnes and I think that was actually on a plate someplace. My 1968 LR had no plate but the books/mags suggested anyplace from 2.0 to 3.5 tonnes https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32021R0535#:~:text=service braking system-,3.1.1.1.,-The technically permissible
Imhotep Posted March 15 Posted March 15 Very blurry, but here’s my old 954cc Citroen AX Debut, complete with functional towbar. Only used it once to tow a friend’s 206 out of harms way. All 48bhp of it didn’t like that. Faker and adw1977 1 1
Faker Posted March 15 Posted March 15 On 15/03/2025 at 07:06, EyesWeldedShut said: GTW is what it is - the vehicle gets a tow weight calculated and then they plate it up by adding that to the GVW/MAM (see Reg 4 in the link) - there's not usually a trailer weight on the chassis plate, that just gets worked out backwards by GTW minus GVW Expand Excellent 👍
andy18s Posted March 15 Posted March 15 On 14/03/2025 at 19:56, sheffcortinacentre said: How come a 4x4 sierra Monocoque can tow way less than a lada niva or jeep Cherokee both also monocoques? Yet a land/range rover Hilux can to a lot more . As I've seen arguments that a Monocoque can tow less than an equivalent vehicle with a separate chassis yet as my first line the sierra/ niva are similar spec? & That 2 & 4 WD is a factor? How is the towing limit of a vehicle arrived at? I presume there must be a formula/regs etc that manufacturers have to follow? Expand Iirc Cherokees were subject to a recall for a weak/flexing chassis,and the fitting of a substantial towbar was part of the strengthening solution .
horriblemercedes Posted March 15 Posted March 15 On 14/03/2025 at 19:56, sheffcortinacentre said: How come a 4x4 sierra Monocoque can tow way less than a lada niva or jeep Cherokee both also monocoques? Yet a land/range rover Hilux can to a lot more . As I've seen arguments that a Monocoque can tow less than an equivalent vehicle with a separate chassis yet as my first line the sierra/ niva are similar spec? & That 2 & 4 WD is a factor? How is the towing limit of a vehicle arrived at? I presume there must be a formula/regs etc that manufacturers have to follow? Expand I don't think that monocoque is really relevant. Range Rovers have been monocoque since 2002 and can tow 3500kg. Since 1998, towing has to be type approved. As part of that type approval, it's basically just a test that the car can set off from a standstill with that weight on a trailer. Before 1998, the manufacturer just stated a max figure and that was that. The manufacturer will get it type approved based on what is safe and what the drivetrain can handle. Or they won't bother if the model is unlikely to tow or will sell in small numbers. Economies of scale. Also, how much can a Niva tow? The gearboxes get shredded regularly even with 60bhp and only road use. I've never known them as a towing legend
sheffcortinacentre Posted March 15 Posted March 15 I was just using the specific vehicles as examples, nivas mentioned due to I believe being able to tow significantly more than it's own weight . As for the no weight plts don't tow, does this mean that some over zealous official at the roadside is going to say I can't tow with a classic? ( This isn't a dig ,it just sounds like more Ill worded paperwork is all)
Talbot Posted March 15 Posted March 15 On 15/03/2025 at 01:06, Faker said: What Talbot is saying is… you can tow more than what is stated as the vehicles towing capacity limit, so long as you don’t exceed the overall gross train weight…. Which is incorrect Expand I have yet to see any legislation that indicates what you're saying is true. All it states is that you must not exceed your vehicle GVW, and you must not exceed the overall GTW. There is not a "towing limit" for most vehicles (unless it's 3.5 tonnes, and that is a license issue, not a C&U issue) I've run these numbers many times, and found information to back up my take on this. I can't find it at the moment, but have definitely read that any "unused capacity" in the vehicle's GVW can be placed on the trailer as long as you do not exceed the GTW. If "towing weight" were a thing, then that figure would explicitly be listed on a vehicle's VIN plate. However, it isn't. You get GVW and GTW and nothing else. I, equally don't want a mud-slinging excercise here, but I'm fairly sure you've interpreted the regs wrong. Many people do on this point.
Faker Posted March 15 Posted March 15 On 15/03/2025 at 13:14, Talbot said: I have yet to see any legislation that indicates what you're saying is true. All it states is that you must not exceed your vehicle GVW, and you must not exceed the overall GTW. There is not a "towing limit" for most vehicles (unless it's 3.5 tonnes, and that is a license issue, not a C&U issue) I've run these numbers many times, and found information to back up my take on this. I can't find it at the moment, but have definitely read that any "unused capacity" in the vehicle's GVW can be placed on the trailer as long as you do not exceed the GTW Expand Ah good luck chief! You alone have interpreted the wording to satisfy your own needs or ends. Every single towing body online use the guidelines I have shared, along with clear indication on .GOV own website for MAM and GTW. But to profess your own stand alone interpretation, when the E Class Mercedes has a documented maximum braked towing capacity of 2,100kg, and offer guidance that goes against ALL credible advice and actual training, deserves to be challenged. GOV website states GTW is fully loaded car and fully loaded trailer - and must not be exceeded. Doesn’t state anywhere that someone can use a half loaded car with overloaded trailer = to reach the same GTW, and permits exceeding vehicle documented towing capacity. When I get the chance I will get document clarification and share.
Barry Cade Posted March 15 Posted March 15 You can't exceed axle weights though. ? Add these together and it comes to nearly the GVW give or take.
Rustybullethole Posted March 15 Posted March 15 Does it look right? Yes; It'll probably be alright then. No; Proceed with trepidation. Does it feel right? Yes; Let's see how fast it will go. No; Proceed with caution. EyesWeldedShut and Semi-C 1 1
Talbot Posted March 15 Posted March 15 On 15/03/2025 at 15:16, Faker said: GOV website states GTW is fully loaded car and fully loaded trailer - and must not be exceeded. Doesn’t state anywhere that someone car use a half loaded car with overloaded trailer = same GTW Expand True, but it also doesn't state that you subtract the GVW from the GTW to get the towing capacity. Yes, many websites do say this, but that is not what the .gov website says, and it doesn't state that there is a towing limit. There's just two weights you must not exceed. loserone 1
Barry Cade Posted March 15 Posted March 15 I'm lost.. and do this for a living... This sort of stuff has been going on for years... What is the actual argument here?
Talbot Posted March 15 Posted March 15 from here: https://www.barlowtrailers.co.uk/the-basics-of-towing-a-trailer-or-van Quote 7.3 GCW - Gross Combination Weight This is specified by the manufacturer of the towing vehicle and it means the maximum permitted weight of the combination (ie total of the towing vehicle and the trailer, including the loads on both). Also known as Gross Train Weight (GTW). To help find the maximum weight of trailer that can be towed, you could subtract the GVW of the towing vehicle from the GCW. (in this example a 2000kg trailer would be permitted). However if the towing vehicle is not fully laden, any spare weight capacity can be used by the trailer, so long as the GCW and trailer GVW are not exceeded. Expand This company has it right. Most other trailer websites make the statement about GVW and GTW but are very wooly on the matter @Barry Cade The argument is thus: Vehicle has a 2310KG GVW and a 4410GTW rating. my argument is that as long as both of these are kept to, then there is no issue. If the car was laden to 2000kg, you could tow a 2400kg trailer if you wanted to. @Faker's argument is that by subtracting 2310 from 4410, you get a trailer weight of 2100kg and you must not exceed that under any circumstances. I believe he's wrong, and that the 2100kg limit is ONLY when the vehicle is laden to it's GVW of 2310kg. Even the .gov website is not clear. I believe that if the law stated that the maxiumum trailer was indeed GTW-GVW, this would be made very clear, and it is not. All they do is state that GVW and GTW must both be adhered to. In my example above, the vehicle would be 2000kg, and hence under the GVW. The combination weight would be 4400kg, and you would be (just) inside the GTW, and hence legal. With all the other bollocks online about the 85% rule (which some websites claim is law.. it isn't) and the 100% rule (trailer should not exceed the weight of the car, also not law) it is very hard to find the exact legal situation. It's an interesting debate, and not the first time this has come up. I'm particularly invested, as I irregularly do tow a trailer of about 2500kg on my W210, but ensure that both the GTW and GVW are not exceeded. I believe this is legal.
LightBulbFun Posted March 15 Posted March 15 On 15/03/2025 at 08:07, Faker said: some light reading 🤣 I’ll dig it all out if I get a chance Expand those weight stuff which you have stated from the construction and use act generally are referring to the maximum weight, any *class* of vehicle is allowed to tow, as in lets say you had a magical motor car that itself was plated for 100 tons GTW, even tho *itself* might be able to do that, it would not be legal for it be registered as being able to do such because it exceeds the weight limit set by the C&U act that a Motor car and trailer can be https://www.legislation.gov.uk/uksi/1986/1078/regulation/76 https://www.legislation.gov.uk/uksi/1986/1078/schedule/11 which you can find in the charts above for example its along the same lines that if certain Lorries or buses are too wide they cant be used on UK roads but said legistation does not clarify what me you and @Talbot are trying to figure out here
Faker Posted March 15 Posted March 15 To be fair to talbot - that’s a decent and coherent reply, which clearly clarifies that has assumptions are his opinion. Credit there fella. But…. Leave it with me…
Faker Posted March 15 Posted March 15 On 15/03/2025 at 16:09, LightBulbFun said: https://www.legislation.gov.uk/uksi/1986/1078/regulation/76 https://www.legislation.gov.uk/uksi/1986/1078/schedule/11 but said legistation does not clarify what me you and @Talbot are trying to figure out here Expand Yeah the C&U stuff requires a lot of delving with dozens of subsections etc. I will get to the bottom of it. the legislation lightbulbfun has documented refers to HGV vehicles etc. check out the axle weights 😉 I do enjoy a good debate!!
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