Simple (?) Weight Calculation

[BarneyRubble1]

I know this is an old chestnut but is there an EASY way to check the safe weight ratio - car to caravan ?

I have tried VERY hard to understand but I am absolutely bamboozled by all the different formulas I read.

There's Mass in Running order; MTPLM; Permissible Gross Weight, Gross Vehicle Mass; Max Towable Mass; Gross Train Mass; Car Payload; Van Payload; User Payload; the list goes on and on...

Is it as simple as Caravan MTPLM over Car Kerbweight x 100 ?

In my case (Swift Charisma) 1290Kg over (Mondeo) Kerbweight 1587 x100 = 81%.

I understand that, as a guide, the ratio should be about 85%. But my question is about which numbers you should use to calculate. There are loads of gobbledygook numbers confusing the issue.

PLEASE can someone make it simple ?

 

[Viking1]

go to this web sit and put your car in then your caravan then it will tell if you are ok and it will give you the % AS well.

http://www.whattowcar.com/index.php
mark

 

[Steve L]

Now then Barney, as Mark has stated visit whattowcar.com and they will tell you what they think is the top weight your car can tow.

Double check this with the franchise dealer who again should have the knowledge.

Finally find the VIN plate on your car. it can be under the bonnet or in the case of my Renault on the oor post by the drivers seat as the door is opened.

The largest figure of weights quoted is the "gross train weight" which is the maximum weight of car plus occupants plus trailer permissable. Now take the family out to the local agricultural merchant's to see the weigh bridge. On the way fill the car with fuel. Now weigh the car with you and the tribe inside. This will now give you a true weight of the car "gross vehicle weight".

By subtracting Gross vehicle weight from Gross train weight, you will now have the legal weight you can tow. This may be over or under the figure quoted by the manufacturer but believe me, the gross train weight is what VOSA and the boys in blue stick to. Well plus 3% allowance for weigh bridge error.

Now as a final test next time you have loaded the car and van for a week away pop over the weigh bridge to see if you are ok to gross train weight as previously described.

Over my thirty years of driving this methodogy has not failed once and no sooner you can show a weigh bridge ticket and talk the talk on Gross train weights and show Mr plod the VIN plate, he will be bamboozeled and often let you on your way congratulating you on your safety knowledge.

Gone are the days where you could show the car weight in pounds and the caravan in tons, hundred weights and quarters, which left even the eignstien of plod scratching their heads. This was an old trick which made the car look well heavy and the trailer look light, until the maths was done.

Oh and by the way, don't think that the mythical 85% guideline will guarrantee a safe tow. Loading is the key to safe towing and paying attention to weight low down over the axle and keeping to the 60-75Kg nose weight will also help a lot.

Hope I have not confussed you too much. If you are still unsure, talk to your local weigh bridge operator or any Lorry driver and they will be only too pleased to help you out.

Steve.

 

[Lutz]

On the whole, I'll go along with what Steve has written. Just don't forget not to exceed the MTPLM of the caravan, either. What you have calculated, Barney, is fair enough, too, but it's only a rough guideline.

 

[Steve L]

On the whole, I'll go along with what Steve has written. Just don't forget not to exceed the MTPLM of the caravan, either. What you have calculated, Barney, is fair enough, too, but it's only a rough guideline.

Doh, I knew I'd forget some thing. Thanks for pointing that one out Lutz, it is a key point to adhere to.

 

[BarneyRubble1]

Thanks, guys, for your comments. I also came accross some helpful previous threads which you have contributed to ('85% Rule' and 'Weighbridge and how ?'). This must be your speciality subject....?

I tried the Whattowcar website but it confuses me further. Some of the specs it produces don't agree with the manufacturer's.

I have a good towcar at the moment (Mondeo) but I will need to downsize as my wife needs to learn to drive (Lord help us!).

I need to go to a 1.6 Ford and have only a limited choice (as it is a company car).

My caravan is a Swift Lifestyle 510-4 (dealer special) based on a Charisma. According to its handbook the Mass in Running Order is 1033Kg, Payload 241Kg, and MTPLM is 1290Kg.

My proposed car is a C-Max 1.6 Dsl Auto and according to the Ford website the Kerbweight is 1476Kg, Gross Vehicle Mass is 1930 and Max Towable Mass is 1200Kg.

So I calculate Van MTPLM 1290Kg over Car Kerbweight 1476, giving a ratio of 87%. Seems simple enough.

But what about the Max Towable Mass of 1290 ? This is more than the caravan.

And the Whattowcar site gives me 106%. I am totally confused.

I can't believe life should be this complicated. ANY clarification you could provide would be MOST appreciated.

Barney

 

[Lutz]

Maximum towable mass is the maximum total axle weight of the caravan that the car manufacturer specifies as the permissible limit. You mention both 1200kg and 1290kg in your response. I presume that 1290kg is a typo error. If 1200kg is the correct figure, then you may tow a caravan with an MTPLM of 1200kg plus the noseweight of the caravan (usually 75kg).

As you see, you will not be able to tow your caravan with it fully laden at 1290kg, because you would then exceed the limit that Ford has specified for the car, even though your calculted weight ratio of 87% is still reasonably good.

 

[Oldfogey]

If your proposed car has a Max Towable Mass of 1200, then that is the limit you can tow.

The basic caravan weighs only 1033, so you can tow this, as long as you do not load it by more than 67kg payload ( and bear in mind that many extras such as spare wheel, oven, microwave etc often have to come out of this).

The car has an available payload of (1930-1476) or 454kg. This has to cover fuel, passengers, and all luggage.

You don't quote a Gross Train Weight, which is the maximum permissable weight of laden car and caravan combined. This is usually (always?) less than the total of the individual items, so you would have to remove further load from the car until you are down to that weight.

You may well find that you can technically tow the outfit, but that the available payload is less than acceptable.

As a radical alternative, had you considered buying a small, second hand car for your wife to learn in? When my wife needed to learn, the Range Rover was obviously not an option (insurance first, and then it was an automatic), so we bought a baby fiat. Nothing fancy was needed, and in fact the reduction in mileage in the main car saved pretty much enough to pay for running the second.

It might not work for you, but give it serious consideration - after all, you will worry less about it getting bent!

 

[Lutz]

Slight corrections to Oldfogey's figures:

If the maximum towable mass is 1200 and the caravan weighs 1033kg, then the difference is 167kg, not 67kg. However, maximum towable mass and the weight of the caravan are not directly comparable because the towable mass is only its axle load, not its total weight.

The available payload of the car does not have to cover fuel (kerbweight includes a 90% full fuel tank) but it does also include the noseweight of the caravan, which was not mentioned.

 

[Oldfogey]

So what's a 100kg between friends?

Actually, quite a useful amount of luggage, and begins to make the project look a bit more plausible.

On the fuel, presumably if you made sure to keep the tank half empty, a few more kilos would be gained.

Good point about the hitch weight - I had forgotten that. It may not actually make much difference, because I suspect the car will not be able to carry it's full payload without exceeding the GTW, for which the noseweight is irrelevant.

 

[BarneyRubble1]

So what's a 100kg between friends?

Actually, quite a useful amount of luggage, and begins to make the project look a bit more plausible.

On the fuel, presumably if you made sure to keep the tank half empty, a few more kilos would be gained.

Good point about the hitch weight - I had forgotten that. It may not actually make much difference, because I suspect the car will not be able to carry it's full payload without exceeding the GTW, for which the noseweight is irrelevant.

Thanks, again, guys. You've given me lots to ponder on. I wish it was not so complicated. I do like my present caravan, and the car. I think I may change the wife....

Barney

 

[BarneyRubble1]

(Sorry - misposted my reply)

Thanks, again, guys. You've given me lots to ponder on. I wish it was not so complicated. I do like my present caravan, and the car. I think I may change the wife....

Barney

 

[Tapestry]

Hi

Appreciate your dilemma. Before you change your car so that your wife can learn to drive your company car, I assume that your company car allows learner drivers to have use of the car. Hubby has a company car, has had one with more than one company. Its been a requirement that drivers of the cars have passed their driving tests.

Agree the Mondeo is a good tow car. Another thought, what happens if you have planned to go away with the caravan and the car has been damaged - happens to experienced drivers, greater risk in my view with inexperienced drivers.

I'd get a cheap, small, second hand hatchback to learn to drive in. Keep the Mondeo. Good luck to your wife with learning to drive. Hope all goes well. Annette

 

[Dave_374230619]

Saw the link and decided to check out my car + van ratio. It came up as a perfect match. Then decided to have a play to see what other cars would be suitable for my caravan. It seems that even if I win the lottery I will be okay to pull my van with either a Farrari Enzo or even a Lamborghini Gallardo. So if ever you do see this compination, give me a wave !!!

 

[BarneyRubble1]

Thanks, Annette, for your thoughts. I am now driving a Jaguar S Type but I have had many Mondeos. I think he Mondeo Estate is a great towcar, with its self levelling suspenion.

My Co will provide me with insurance cover for a learner but only in a 1.6 or 1.8 diesel. That is why I am trading down.

But I have to get a Ford - about which I am not displeased. I am more than happy with them. A cheap 'banger' in which to learn is a good idea - after all, she is only a woman driver. But insurance is likely to be expensive.

I do take your valid point, though, about the potential for an 'oops' just before the holidays if I have only 1 main car.

Mind you - even I could do that - and I'm a superior male driver ! (Only joking, honest)

Barney

 

[t_374241894]

Now then Barney, as Mark has stated visit whattowcar.com and they will tell you what they think is the top weight your car can tow.

Double check this with the franchise dealer who again should have the knowledge.

Finally find the VIN plate on your car. it can be under the bonnet or in the case of my Renault on the oor post by the drivers seat as the door is opened.

The largest figure of weights quoted is the "gross train weight" which is the maximum weight of car plus occupants plus trailer permissable. Now take the family out to the local agricultural merchant's to see the weigh bridge. On the way fill the car with fuel. Now weigh the car with you and the tribe inside. This will now give you a true weight of the car "gross vehicle weight".

By subtracting Gross vehicle weight from Gross train weight, you will now have the legal weight you can tow. This may be over or under the figure quoted by the manufacturer but believe me, the gross train weight is what VOSA and the boys in blue stick to. Well plus 3% allowance for weigh bridge error.

Now as a final test next time you have loaded the car and van for a week away pop over the weigh bridge to see if you are ok to gross train weight as previously described.

Over my thirty years of driving this methodogy has not failed once and no sooner you can show a weigh bridge ticket and talk the talk on Gross train weights and show Mr plod the VIN plate, he will be bamboozeled and often let you on your way congratulating you on your safety knowledge.

Gone are the days where you could show the car weight in pounds and the caravan in tons, hundred weights and quarters, which left even the eignstien of plod scratching their heads. This was an old trick which made the car look well heavy and the trailer look light, until the maths was done.

Oh and by the way, don't think that the mythical 85% guideline will guarrantee a safe tow. Loading is the key to safe towing and paying attention to weight low down over the axle and keeping to the 60-75Kg nose weight will also help a lot.

Hope I have not confussed you too much. If you are still unsure, talk to your local weigh bridge operator or any Lorry driver and they will be only too pleased to help you out.

Steve.

Hi, just need some help deciding if we've got a siutable match or not?

The car is a VW GOLF 2.0 GT TDI 2004 MK5 with a max towing weight of 1400kg.

Were looking at a Bailey Pageant Burgundy, this has an unladen weight of 1180kg and fully laden weight of 1400kg.

ive been advised that realistically 220kg is a lot of payload to carry.

How do you think we would stand, is this a suitable outfit?