Towing Car Kerbweight and Actual Caravan Weight

May 3, 2019
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Good morning everyone.

We started caravanning last year with an old van and have really enjoyed it. Our first van is a 2001 Abbey Freestyle 520SE. We are now considering an upgrade because we find it a little small with children and a dog.

We have been looking at a Swift Sprite Major 6 TD. But our problem is our tow car.
We have a 2011 Suburu Outback with a kerbweight of 1648kg.

The major has a MIRO of 1307kg and a MTPLM of 1528kg, the payload is then 221kg. Using the 85% recommendation then the maximum MTPLM our car can tow is 0.85 x 1648kg = 1401kg.

My understanding is that this limit is recommendation based on the relative masses of the car and the van so that under a dynamic situation (snaking) then the car is the heavier component and this is what controls the dynamic response of the combined car and van. Hence actual masses, not the plated figures.

My question is then, if we limit the payload to 94kg (1401kg - 1307kg) then the total mass is less than 85% of the kerbweight so would follow the recommendation?

The other question, was it we could find a van that has had its Plated MTPLM increased by the manufacturer, could we use the old MTPLM and take 85% of the lower figure?

The car has a maximum towing weight of 1700kg and my license is B+E issued in 1996.

Thanks for your help.
Phil
 
May 7, 2012
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The B+E licence means you are able to tow the combination without problem there.
The 85% figure is a recommendation for newcomers to towing caravans and is not law. Legally you can tow a caravan up to the towing limit of the car but in your case this would be unwise.
The Subaru has a good reputation as a tow car and you have some experience of towing, so while the ratio is on the high side at just over 92% it should work. I would take it easy when towing and get used to the different caravan. The 221kg user payload is quite high and it should be easy enough to keep the load within this, personally I would aim at 90% rather than try to get down to 85% which is probably impractical.
 
Nov 11, 2009
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The B+E licence means you are able to tow the combination without problem there.
The 85% figure is a recommendation for newcomers to towing caravans and is not law. Legally you can tow a caravan up to the towing limit of the car but in your case this would be unwise.
The Subaru has a good reputation as a tow car and you have some experience of towing, so while the ratio is on the high side at just over 92% it should work. I would take it easy when towing and get used to the different caravan. The 221kg user payload is quite high and it should be easy enough to keep the load within this, personally I would aim at 90% rather than try to get down to 85% which is probably impractical.

I’d agree with Raywood and clearly you have thought about the possible upgrade. As you say you don’t have to load the van to it’s MTPLM limit which is always good. Plus your car will take a good volume of luggage so keeping the van light and car heavy is a sound principal. Also as you will be aware Caravan load placing is important as so is using your maximum noseweight. Subaru’s have a good reputation as tow cars (mainly horse boxes) so I see no problems in your proposed upgrade.

if you found a van with an upgraded payload it’s not a problem if your actual payload carried us less. Assuming that the upgraded MTPLM does not lead to you exceeding the legal plated restrictions of the car or your licence. But with 221kg payload on the Sprite is there an option to increase it further?
 
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Mar 14, 2005
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Hello Phil,

All the previous responses have given what I think is good advice.

But I would like to stress the 85% advice whilst echoing the principle of keeping the trailer as light as possible, does not guarantee either safe or a good towing experience on its own. It equally as important to ensure both the car and the caravan are properly maintained. Already being a caravanner you will understand how much extra time and space you need to keep for manoeuvres, and obviously an even heavier caravan will detract more from acceleration and handling.

Your question about increased MTPLM.
As you have already got Cat BE, you are licenced to drive any combination of car and caravan. The only proviso is the combined measured weight (not the combined MAM) of the outfit falls within the tow vehicles Gross Train Weight. - This is a legal limit, as are the other values on teh cars VIN plate.

The industries towing ratio has no legal force, so there is nothing to be gained for changing the caravans MTPLM, unless you need more payload capacity for your items.

Not all caravans can have their MTPLM figure increased. Some are already at the top load for their chassis and simply cannot be increased. Others are dependant on the caravan manufacturers policy on upgrading, some will not up grade secondhand caravans, or caravans that are over a certain age.

There is some good sense to load the tow vehicle and reduce the load in the trailer, it does not change the industries calculation of towing ratio (Caravan MAM/ Cars Kerbweight) I know how illogical this seems, but that's the way they do it. and because it has no legal implication, provided teh outfit tows safely, I shouldn't lose any sleep about it.
 
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The MTPLM is the maximum weight and includes the payload. The payload is not additional to the MTPLM. I am assuming that the Sprite is post 2012 and included should be the weight of 20kg gas bottles, EHU lead and perhaps some other stuff. As these came standard with the caravan they shoudl be included in the MIRO of the caravan.
 
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The MTPLM is the maximum weight and includes the payload. The payload is not additional to the MTPLM. I am assuming that the Sprite is post 2012 and included should be the weight of 20kg gas bottles, EHU lead and perhaps some other stuff. As these came standard with the caravan they shoudl be included in the MIRO of the caravan.
My Sprite included 1 x 6 kg gas bottle which if not Calorlite can be 12-14 kg. The electric lead. Water inlet hose. Documents and handbooks and step. No fluids.
Looking at the OPs calcs the payload is within his MTPLM figure and is accurate as regards MIRO plus payload = MTPLM. But trying to run at 90kg approach load would be neigh on impossible given the weight of battery, and any mover. But the Outback will handle that Caravan. My last Forester was a 2.0 non turbo CVT it towed fine albeit with a good few revs at times. But the Outback will be 2.0 diesel or 2.5 petrol non turbo. Either will be fine. The OP could look at Towcar. info and input the outfit details for a “match”.
 
Oct 17, 2010
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Good morning eve

We have been looking at a Swift Sprite Major 6 TD. But our problem is our tow car.
We have a 2011 Suburu Outback with a kerbweight of 1648kg.

The major has a MIRO of 1307kg and a MTPLM of 1528kg, the payload is then 221kg. Using the 85% recommendation then the maximum MTPLM our car can tow is 0.85 x 1648kg = 1401kg.


Phil
The pay load is part of the MTPLM . so you could use the full payload, but don't forget your motor may have some space. Just be on your best driver behaviour, I towed happily at 98% for a few years. The 85% is only a guide, for total beginners, though a good one.
 
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My Sprite included 1 x 6 kg gas bottle which if not Calorlite can be 12-14 kg. The electric lead. Water inlet hose. Documents and handbooks and step. No fluids.
Looking at the OPs calcs the payload is within his MTPLM figure and is accurate as regards MIRO plus payload = MTPLM. But trying to run at 90kg approach load would be neigh on impossible given the weight of battery, and any mover. But the Outback will handle that Caravan. My last Forester was a 2.0 non turbo CVT it towed fine albeit with a good few revs at times. But the Outback will be 2.0 diesel or 2.5 petrol non turbo. Either will be fine. The OP could look at Towcar. info and input the outfit details for a “match”.
Normally in the owner's handbook it states what is include din the MIRO. I guess if the year of the caravan was known you could offer the OP some valuable advice. BTW if they are looking at buying new then they should seriously consider having the ATC fitted as it is an option adn especially if the keep the current vehicle. There is also the option to upgrade the MTPLM on some models.
 
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Our motor is a 2L diesel.

I didn’t realise that things like gas bottles and the battery were not included in the MIRO figure. I presume it is because they are removable?

I think new would be out with our budget, hoping to get one that is maybe 3 years old .
 
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Our motor is a 2L diesel.

I didn’t realise that things like gas bottles and the battery were not included in the MIRO figure. I presume it is because they are removable?

I think new would be out with our budget, hoping to get one that is maybe 3 years old .

I got my MIRO inclusions from Swift technical but as said in a later post it should be in the Owners Manual. Some two berth vans have a payload of 125kg. That has put us off going for a two berth with inclusive self contained shower unit. At 220kg thats a useful payload and you would find the next model range up had less payload as it had more kit fitted.
Makers are now realising that playing MTPLM to be too low may be attractive as cars have been getting lighter but may have a counter effect on other buyers who realise how quickly 125 kg (eg)!can be used up especially with children and dogs etc.
 
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After a new rear panel replacment, I reloaded with the caravan with the knifes forks plates Bits and pieces etc and took it to a weigh bridge I was 40 kg over the max weight of the caravan. Went home and took out things, 3, 2 litre bottles of toilet chemicals 1 kg of extra awning pegs, 4 tins of baked beans, games, scrabble etc, 2 kg. Unloaded 80 kg of non eessential stuff.
We are still close to our max limits , so be carefull.
 
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Beware of any published MIRO figure as it rarely corresponds to the weight of the caravan in question. It's always a generic figure that normally applies to a vehicle with the absolute minimum of factory-fitted equipment. As such it is almost invariably less than the actual figure. Therefore, it's always safest to put the caravan on a weighbridge.
 
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Beware of any published MIRO figure as it rarely corresponds to the weight of the caravan in question. It's always a generic figure that normally applies to a vehicle with the absolute minimum of factory-fitted equipment. As such it is almost invariably less than the actual figure. Therefore, it's always safest to put the caravan on a weighbridge.
I don’t really understand your comment about “absolute minimum of factory fitted equipment”. Surely a caravan model has a fitted equipment specification and an associated MIRO. If the initial purchaser orders additional optional extras they come out of payload but MIRO stays unchanged. Similarly fir an subsequent owner too. Enhancements such as movers, second gas cylinder and solar will also come out if payload unless they are quoted in the as-made specification. But weighing your van “ empty” is a good idea irespective
 
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The MIRO figure for any caravan is rarely accurate due to manufacturing tolerances, and things like the level of humidity, so it isn't a figure you can rely on.

I know some caravanner's religiously weigh everything they put into their caravans, and use the MIRO as their base line, and hope that by adding their weighed items sub total, it will give their total all up weight, but that depends on how accurate the MIRO figure is, and the accuracy of the weighing device used for the pay load. And because of those uncertainties, it is still possible to exceed the MTPLM.

The final arbiter and more important value is what the caravan actually weighs when it's loaded so it can be compared to the caravans MTPLM.
 
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Our motor is a 2L diesel.

I didn’t realise that things like gas bottles and the battery were not included in the MIRO figure. I presume it is because they are removable?

I think new would be out with our budget, hoping to get one that is maybe 3 years old .
Most post 2012 caravans have gas bottles, EHU lead, steps included. Some like ours have gas bottles, EHU lead, steps, wastemaster and battery included in the MIRO.
 
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The final arbiter and more important value is what the caravan actually weighs when it's loaded so it can be compared to the caravans MTPLM.

And that is all it boils down too.

Weigh the caravan completely empty, then count everything as payload, up to the MTPLM , if you carry that much.

Seems to me that everything else, apart from the MTMPL, are mystical figures that only serve to confuse all in sundry.

As for essential equipment, again is open to many interpretations. After all a change of underwear can be considered. "Essential"
 
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I can't get too excited about it. We only carry one gas and load the car. Never weighed it in our6 years caravanning and not going to . Police can't even stop loonys on their phones .
 
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I doubt it is possible to get the payload down to 94kg and would not try. With two adults and two children you are bound to excede that figure. or overload the car. The caravan has a very high payload and provided you do not go silly you should be well within this and should be fine.
The unladen weight of the caravan can vary as the Prof saysas the published figure is from a sample and individual caravans are not weighed on completion. It might be worth using a weighbridge to check this if you are worried about weights.
 
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And that is all it boils down too.

Weigh the caravan completely empty, then count everything as payload, up to the MTPLM , if you carry that much.

Seems to me that everything else, apart from the MTMPL, are mystical figures that only serve to confuse all in sundry.

As for essential equipment, again is open to many interpretations. After all a change of underwear can be considered. "Essential"
Hello Dave,

I do appreciate that theoretically knowing what your MAM-MIRO figure is of some use, as it gives you a theoretical loading margin. But it just seems illogical to weigh an empty vessel and then try to fill it with a jumble of items and to try and to assume you have enough information to keep the whole thing under its Max Authorised Mass (MAM = MTPLM)

Even if you weigh every item you put in the caravan and keep a running total (And I know many do) every small measurement you take will contain some error, and that error will be compounded as the number of items grows. This could lead the real weight of the items to be more or less than the calculated figure. If its more then it could lead to an overload situation, if its less then you may deprive yourself of taking some items with you.

Almost inevitably some items will sneak in below the weighing radar, the site booking conformation letter, the tourist leaflets and maps for the area, the bottle of suntan lotion, Loaf of bread etc . etc... and these all add up.

If the critical factor is the MAM then it make more sense to measure the loaded caravan to give you certainty about your legality, and then if necessary work backwards to remove the non essential items to get down to your desired value.

I was lucky , One company I worked at had a flusj to teh ground calibrated industrial scales used to check stillages of castings (3000kg Cap +/-1Kg) flush to the ground. I could weigh each wheel of a vehicle and calculate the weights and loading's.
 
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I don’t really understand your comment about “absolute minimum of factory fitted equipment”. Surely a caravan model has a fitted equipment specification and an associated MIRO. If the initial purchaser orders additional optional extras they come out of payload but MIRO stays unchanged. Similarly fir an subsequent owner too. Enhancements such as movers, second gas cylinder and solar will also come out if payload unless they are quoted in the as-made specification. But weighing your van “ empty” is a good idea irespective

The published MIRO applies only to the one caravan that the manufacturer submitted for type approval. If he later adds items as standard that were previously offered as an option, the MIRO will not change unless he resubmits the caravan with the revised specification for type approval. As a result, the quoted MIRO may not necessarily agree with weight of a standard caravan in the as-made specification.
 
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The published MIRO applies only to the one caravan that the manufacturer submitted for type approval. If he later adds items as standard that were previously offered as an option, the MIRO will not change unless he resubmits the caravan with the revised specification for type approval. As a result, the quoted MIRO may not necessarily agree with weight of a standard caravan in the as-made specification.

Thanks.
Doesn't say much for Type Approval control does it? On systems that I worked on you could seek, and hopefully receive, approval for a change by submitting revised documentation dependant on the type of change being proposed whilst still retaining configuration control. Would have thought that a maker could have some degree of authority to make certain changes to the type approval within a defined scope.
 
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Thanks.
Doesn't say much for Type Approval control does it? On systems that I worked on you could seek, and hopefully receive, approval for a change by submitting revised documentation dependant on the type of change being proposed whilst still retaining configuration control. Would have thought that a maker could have some degree of authority to make certain changes to the type approval within a defined scope.

Amendments to type approval data are a relatively costly administrative affair for the manufacturer. As the MIRO value has little consequence in any legal requirements, he will try to avoid resubmission. It is easier for him to submit a vehicle with an absolute minimum of equipment and declare every additional feature as a factory-fitted option even though well nigh every vehicle will leave the factory as standard with that feature. It gives him the freedom of removing, replacing or adding features at any time without having to go through the type approval process.
 
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I think the best advice is to make use of the car storage as much as possible and minimise the payload added to the van.

In addition I would think it good practice to keep the centre of mass of the payload as close to the axles as possible to reduce thetendency to yaw.
 

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