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[Ste6t9]

I've definitely gone down a rabbithole here. I've now downloaded the Mitsubishi manual direct from their site (see below)

For our model: the 2.2 D-iD A/T for 7 persons - with the optional extras because it is the 4 level trim with all the bell and whistles (and it is the 7 seater) The kerbweight (which they state is as standard with one person and a full tank of fuel) is 1710kg

So this falls somewhere between the quoted 1685kg by Towsafe and the very conservative 1750kg that I got at the weighbridge if I was 19.5 stone (which I am not)

Whereas as you saw earlier, it came off the weighbridge almost as standard at 1810kg

What a minefield!!!

 

[Ste6t9]

You should have received a printed copy of the results which includes the weighbridges limits of accuracy - only then can you make a fully informed assessment of the reported weights.

Published kerbweights are not a true representation of the vehicle you have, but relates to the generic model the manufacturer used for the type approval process. Consequently any variation to the standard equipment your vehicle may have will not be reflected in the published figures.

There are a whole host of manufacturing variations that will affect individual cars, for example the type of gear box, some paint finishes are heavier than others and it account for up to about 8kg. Tyres and or wheels, Thickness of carpets and upholstery materials, more powerful in car entertainment options have 5kg or heavier subwoofer, and as any engineer will tell you something as complicated as a car has so many different materials and each will have tolerances that will change weights. Don't forget all the knick-knacks in the door pockets and glove box - the umbrella and ice scraper in the boot etc....

There are few real occasions where anyone needs to know the kerbweight of their vehicle. from a legal perspective its the overall weight limits that are far more important, and you ability to ensure you do not exceed them.

Thanks for this Prof!

I agree that as the 85% is a guide, the overall weight of the outfit is what will be looked at when we get pulled over (as well as the load on the rear axle of the towcar)

The car has a GTW of 4260kg so I reckon I'm ok on all accounts and it all comes down to my confidence to tow at a higher ratio (and of course the insurance issue)

I wasn't offered any printout of readings as it is a public weighbridge (turn up, press the button and proceed at the green light) but it would have been nice to have it.

 

[ProfJohnL]

...I wasn't offered any printout of readings as it is a public weighbridge (turn up, press the button and proceed at the green light) but it would have been nice to have it.

I've never seen one like that before, and what great idea! But its useless unless yo know its calibrated capability. Somewhere at the site there should be a statement about the accuracy of the weighbridge.

 

[Lutz]

I think the V5 or perhaps the VIN figure is the vehicle empty of fuel, liquids and people?

The weight plate doesn't show the kerbweight which is what you need if you want to calculate the weight ratio.

Sorry, I didn’t mean the VIN or the V5 figures. I meant the figures that are published everywhere for this model. The number that comes up constantly is 1685 kg

Published figures are generally the MIRO and that is the weight of the vehicle as submitted by the manufacturer for type approval, not the actual weight of the car in question. There can be quite a difference depending on any difference in spec between the two.

 

[Stagn8]

I have exact same vehicle, same year and went through all the loops you have. Gave the Mitsubishi help desk a call and the helpful young lady took reg. number and came back to with weight figure which included tow bar. I asked for confirmation in writing (With official headed paper) including chassis number which she did. The figure was around 1860 kg which ties up with your weighbridge figure.

 

[Ste6t9]

I have exact same vehicle, same year and went through all the loops you have. Gave the Mitsubishi help desk a call and the helpful young lady took reg. number and came back to with weight figure which included tow bar. I asked for confirmation in writing (With official headed paper) including chassis number which she did. The figure was around 1860 kg which ties up with your weighbridge figure.

Unbelievable.

Where did you go to get this information? Is there a link or a number to call?

 

[Lutz]

For every vehicle manufactured since I believe 2012 the manufacturer has had to document its actual weight in the type approval certificate of conformity. If you don't have that certificate, by referencing the chassis number, the manufacturer should still be able to let you know what the actual weight is.

 

[Stagn8]

Here you go.

01285 647774

 

[Raywood]

Personally I would not take risks with weights. Different cars perform differently as tow cars, you can never be sure of a combination until you try it and if it is wrong it is too late.

 

[Lutz]

Personally I would not take risks with weights. Different cars perform differently as tow cars, you can never be sure of a combination until you try it and if it is wrong it is too late.

If different cars of the same weight perform differently there is always going to be a risk that the combination is going to be suboptimal and it may be too late.

 

[Darren.H]

Thanks for this Prof!

I agree that as the 85% is a guide, the overall weight of the outfit is what will be looked at when we get pulled over (as well as the load on the rear axle of the towcar)

The car has a GTW of 4260kg so I reckon I'm ok on all accounts and it all comes down to my confidence to tow at a higher ratio (and of course the insurance issue)

I wasn't offered any printout of readings as it is a public weighbridge (turn up, press the button and proceed at the green light) but it would have been nice to have it.

You in Morley?
The free to anyone dynamic axle weigh machine I used was basically drive to the line, press the button then when the light comes on drive over, the weight being displayed on the nicely large display

 

[Ste6t9]

You in Morley?
The free to anyone dynamic axle weigh machine I used was basically drive to the line, press the button then when the light comes on drive over, the weight being displayed on the nicely large display

No mate, but I know the one you mean at Gildersome as I used to drive trucks over there. Ours is at the ferry port in Hull. Open 24H

 

[Darren.H]

No mate, but I know the one you mean at Gildersome as I used to drive trucks over there. Ours is at the ferry port in Hull. Open 24H

Thats the one, 😄

 

[Hutch]

For the % car/caravan ratio, As there is no legal ratio, I go with the weight of the car with the minimum equipment , if I were to be towing my caravan. And the lowest amount of fuel in the car, So Myself , cadac, awning, kojack etc. Against my fully loaded caravan. .

 

[Ste6t9]

I have exact same vehicle, same year and went through all the loops you have. Gave the Mitsubishi help desk a call and the helpful young lady took reg. number and came back to with weight figure which included tow bar. I asked for confirmation in writing (With official headed paper) including chassis number which she did. The figure was around 1860 kg which ties up with your weighbridge figure.

Called them today - I’ve asked them to try again because their first kerbweight they gave me was 1610kg.

so now I have measurements ranging over a quarter of a tonne. 🙄🙄

 

[Stagn8]

That’s frustrating! I suppose it all depends on the operator you get, I must of got lucky!. Perhaps you could ask them for a copy of the COC as mentioned by LUTZ previously.
I think that weight is straight out of the handbook and possibly refers to the van version as the base model. I do hope they sort it for you as 1610kg for a large, diesel, fully equipped 4x4 seems ridiculously low. I tow a 1650kg single axle van with not even a hint of instability. I know that doesn’t help with getting the weight sorted but when you do it is a stable tow car with a reasonably heavy van behind.

 

[ProfJohnL]

This thread is another example of how inadequate the present industry weight ratio calculation is. Its using data which is often hard to find.

I fully support the thinking that suggest keeping the trailer as small and light as possible which seems to be one of the fundamental reasons behind the advice, and in the absence of any better solutions it seems logical to consider the worst possible towing scenario - a completely empty car (kerbweight) and a fully loaded caravan (MTPLM). But it's far from realistic. and often difficult to find the relevant accurate data for the tow vehicle.

And on top of that I have personally known outfits where event below 85% they were very prone towards instability and other outfits where possibly even higher than 110% they were a good tow.

There are some tow vehicles where their maximum towed weight limit was lower than 85%.

There is no guarantee that following the advice will result in a safe match or will be stable or a decent tow.

No-one in the industry will publicly admit to knowing how these specific values were derived and what evidence there is that they are the best values to use. I have asked contacts I have in the industry, if they know of any testing or practical work or information that was used, and no-one has ever admitted to me of knowing precisely how this advice came about. There are anecdotal stories, but a scarcity of verifiable facts.

It really needs to be brought up to date, We need a process that:-

• Encourages weight saving.
• Utilises technical data for the specific tow vehicle and trailer involved and checks for legal weight limits compliance.
• Predisposes correct loading to minimise Yaw inertia and to generate an adequate nose load.
• Reminds about maintenance of car and caravan including tyre condition and pressures.,
• Reminds about good driving techniques including defensive driving awareness to avoid loss of control and steps to regain control if the onset of instability arises.
• Informs about Speed limits.

 

[Ste6t9]

So I’m at the decision point where I’ve weighed the car as near to dead empty as possible and got a weight of 1860kg (I am taking this as my kerbweight for the sake of this discussion) I also had a reading of 810kg on the rear axle.

If I’m reading the plate correctly (see picture), then theoretically I can load the car with a payload of 430kg providing the load from the caravan nose AND the car payload doesn’t exceed 440kg (because that would overload the rear axle of the towcar)

In addition to this, the MPTLM of the van plus the MAM of the towcar cannot exceed the GTW of 4390kg (which it doesn’t)

Therefore as long as I am loading sensibly, checking the noseweight and doing a couple of family trips to the weighbridge fully laden for a holiday then I reckon I’ll be able to configure the outfit to be well within legal limits, stable to tow and somewhere within 85%-95% region. (According to my own kerbweight taken at the weighbridge)

If I DON’T load the car at all, and load the van to its MTPLM, then the ratio is just short of 93%.

 

[ProfJohnL]

Hello Ste6to9.

You wrote
"In addition to this, the MPTLM of the van plus the MAM of the towcar cannot exceed the GTW of 4390kg (which it doesn’t) "

This isn't right.

The Gross Train Weight (4390kg) is a limit. and its the combined measured weights of the tow vehicle and trailer that must not exceed the GTW. You quoted using combined weight limits which is not the same.

For example I have a large box trailer with an MTPLM of 2 tonnes, but empty its only 600kg.
I can pull this behind a car with a 1800kg towed weight limit provided I do not add more than1200kg of load (which I never get near to any way). So its not the MTPLM its the actual load.

On another point, whilst its usually the case that load added to the car tends to load the rear axle, in point of fact some of it is shared with the front axle. It of course depends on exactly where the load is applied but for example front seat passengers will tend share their weight with both axles where rear seat passengers will be biased to wards the rear axle. So I don't think its going to make a massive difference for you.

Particularly as you seem to be looking at operating very near to the rear axles load limit, you should be made aware that the trailer's nose load "X" will be added to the rear axle, but becasue of the effects of leverage it will be multiplied a bit "X+Z" The value of Z is dependant on the geometry of your car and any overhang it has. The extra bit "Z" will be deducted from the front axles load so the net increase on the car is only "X" but it might affect your rear axle load margin.

 

[Ste6t9]

Hello Ste6to9.

You wrote
"In addition to this, the MPTLM of the van plus the MAM of the towcar cannot exceed the GTW of 4390kg (which it doesn’t) "

This isn't right.

The Gross Train Weight (4390kg) is a limit. and its the combined measured weights of the tow vehicle and trailer that must not exceed the GTW. You quoted using combined weight limits which is not the same.

For example I have a large box trailer with an MTPLM of 2 tonnes, but empty its only 600kg.
I can pull this behind a car with a 1800kg towed weight limit provided I do not add more than1200kg of load (which I never get near to any way). So its not the MTPLM its the actual load.

On another point, whilst its usually the case that load added to the car tends to load the rear axle, in point of fact some of it is shared with the front axle. It of course depends on exactly where the load is applied but for example front seat passengers will tend share their weight with both axles where rear seat passengers will be biased to wards the rear axle. So I don't think its going to make a massive difference for you.

Particularly as you seem to be looking at operating very near to the rear axles load limit, you should be made aware that the trailer's nose load "X" will be added to the rear axle, but becasue of the effects of leverage it will be multiplied a bit "X+Z" The value of Z is dependant on the geometry of your car and any overhang it has. The extra bit "Z" will be deducted from the front axles load so the net increase on the car is only "X" but it might affect your rear axle load margin.

Thanks for pointing that out John.

To be clear, I don’t intend to operate anywhere near the limits. I was looking at the very worst case scenario eg: the van loaded to its Max and the car also the Max which I definitely don’t need to or intend to do. (However the I was pointing out that provided the rear axle isn’t overloaded, I would have a legal outfit and the combined maximums do not actually reach the GTW - this would actually only come to 4114kg IF I loaded car and van to their respective limits, which I certainly won’t be doing)
I have a spreadsheet of all equipment and its weights therefore will be distributing and weighing back and forth a few times to find the most stable, and obviously, legal outfit.

 

[ProfJohnL]

Just a note regarding the spreadsheet approach to load weights. Its worth doing as it might open a few eyes, but the calculated load can often be a few percent of the actual load due to cumulative errors inherent in make a lot of small measurements then adding them together. I know this from practical experience during stock takes, we always had to do sample counts of some small items like fixings, rather than totally rely on the weight of 10 units divided in to the weight for whole batch.

I suggest when you have your caravan fully loaded another visit to the local weighbridge just to check.

 

[Ste6t9]

Just a note regarding the spreadsheet approach to load weights. Its worth doing as it might open a few eyes, but the calculated load can often be a few percent of the actual load due to cumulative errors inherent in make a lot of small measurements then adding them together. I know this from practical experience during stock takes, we always had to do sample counts of some small items like fixings, rather than totally rely on the weight of 10 units divided in to the weight for whole batch.

I suggest when you have your caravan fully loaded another visit to the local weighbridge just to check.

Yes, as I said. I’m lucky that the weighbridge at the ferry port is only 20 mins away so I intend to use the spreadsheet to roughly decide where to put things and then have a drive over and with it as an outfit.

 

[Hutch]

Ste619, what is the Mtplm of your caravan. ?
Unless you are really on the limits of the max weight in your car and caravan Max train weight. You will be Ok.
Overloading your rear axle could be a problem, and it can be easily done, as Witter tow bars, fitted to Kia and Hyundai , cars tend to exceed the suggested distance from the rear axle, to towball. Giving a higher axle load.
I see many caravan outfits travelling with top boxes, children in the back of cars Packed with Sleeping bags etc, and wonder whats is in the caravan , three kids bikes a 30 kg awning, case of wine and a case of beer,

Its best like you, to be asking to be safe. And I applaude you for that.

Thankfully for me No kids with us so we can pack the beer and Cadac in the car.
And I have never towed overweight,😢 well only a few times maybe.

 

[Ste6t9]

Ste619, what is the Mtplm of your caravan. ?
Unless you are really on the limits of the max weight in your car and caravan Max train weight. You will be Ok.
Overloading your rear axle could be a problem, and it can be easily done, as Witter tow bars, fitted to Kia and Hyundai , cars tend to exceed the suggested distance from the rear axle, to towball. Giving a higher axle load.
I see many caravan outfits travelling with top boxes, children in the back of cars Packed with Sleeping bags etc, and wonder whats is in the caravan , three kids bikes a 30 kg awning, case of wine and a case of beer,

Its best like you, to be asking to be safe. And I applaude you for that.

Thankfully for me No kids with us so we can pack the beer and Cadac in the car.
And I have never towed overweight,😢 well only a few times maybe.

The MTPLM of the van we are looking at is 1724kg. The towcar is a Mitsubishi with a Witter towbar

 

[Buckman]

If your vehicle has a payload of i.e. 300kg on the rear axle and caravan has nose weight of 100kg does this mean that you can only load 200kg into the vehicle.

We tend to put the really heavy stuff like awnings as far forward as possible so the weight is "shared" between front and rear axles i.e. awning is up against back of drivers seat as rear seats are folded down. Luckily with our vehicle will probably never get anywhere near the maximum payload.