I'm new and very confused...

[Crumpeteer]

Hi, I’m new, but not just to the forum but to caravans in general.

My first question: What is the largest, and at the same time safest, size caravan to tow?

The towing vehicle is a BMW 3.0l; 6 cylinder; 204hp; 410nm torque.

Kerb weight = 1630kg.
Ready for road, with 75kg load, fuel level 90%, excluding optional extras.

Permissible gross weight = 2055kg.

Trailer towing = 2130kg.

Braked gradients up to 12% = 1800kg

Braked gradients up to 8% = 1800kg

Trailer nose weight = 75kg

Rear axle load limit – towing a trailer = 1215kg.

It’s quite likely that some of the above is irrelevant, but better to give you more details than not enough.

I’m finding it all quite involved with some people stating 85% of cars kerb weight and others stating not to exceed the cars kerb weight. Another thought is that the car can safely tow a higher load due to an accessory named Al-Ko ATC. I’m really confused….Help!

I hope some of you can shed some light on this, and if so, thank you all in advance.

 

[WoodlandsCamper]

Two major points from what you said:

1. Quote "and at the same time safest, size caravan to tow"
Safety does not come from numbers only, it is how you load the van and how you drive it.

2. Quote "the car can safely tow a higher load due to an accessory named Al-Ko ATC"
INCORRECT. Automatic Trailer Control is NOT there to be able to tow higher loads. It can help you get out of trouble, but you should not have put yourself in trouble in the first place.

The recommendations for a person new to towing is that the max loaded weight of the caravan (MTPLM) is no more that 85% of the kerb weight of the car, and the MTPLM has to be lower than the max tow weight of the car. From the figures you give:

Kerb weight is 1630 kg, 85% of which is 1385 kg, which is less than 1800 kg max braked towing so is OK.

The gross weight of the car is 2055 kg plus MTPLM of van at 85% (1385 kg) = 3440 kg (within a normal driving licence). With an increase of 60 kg on the MTPLM of the van you would need a B+E category licence. (towing ratio 89%).

 

[Raywood]

Just to clarify a point the Gross train weight is the maximum weight the car can restart on a 12% hill five times but should not be regarded as a safe figure for towing a caravan. The 85% figure is suggested as a safe one for new comers to towing but is not law and going over it by a couple of percentage points should not be a problem.
Basically the idea is the car has to have enough weight to control the trailer and exceeding the cars kerb weight leads you into situations where this might not be the case. The large flat sides of caravans are susceptible to cross winds and the bow waves of heavy vehicles so a decent margin of error is needed.
The kerb weight is regarded as the absolute limit for towing by most authorities but something considerably less is it far safer. Personally 90% is about as high as I would go but many people manage 95%. At that point though you are relying on your tow car to be one of the better ones.
BMW's are generally good tow cars but I have no actual experience of yours. It does have ample power for towing though from your figures so should be a good choice within its limits.
The rear axle load limit recognises that if you put lots of items in the boot and then hitch up to a caravan you could be putting a lot of weight on that and some care is needed to keep within this. You would need to check on a suitable weighbridge to know what you actually have there by the way of weight though so most people will just have to err on the side of caution.
Hope this helps but if you have further problems you will find the answer here.

 

[tenpole]

I find the whole weight recommend confusing also. However I have a L200 so tow whatever.

 

[Raywood]

I find the whole weight recommend confusing also. However I have a L200 so tow whatever.

Basically the maximum towing weight is what the vehicle can restart and tow without damaging the working parts. There is however a world of difference between towing say a broken down car slowly round town and a larger flat sided but lighter caravan down a motorway at 60mph. You need to be far more aware of the effect of crosswinds and other traffic on a caravan and lower weights are usually the safer option with caravans where as in town with a heavier load it is probably the clutch that is the most vulnerable thing due to stopping and starting.

 

[LizziePope]

Hello and welcome to the Practical Caravan forum. Thanks for posting. We've some videos which might help – please click here!

 

[tenpole]

Again another reason why towing a caravan will be much harder than an artic. Even with an empty curtain sider there is still a few ton of weight with all the axles set up, and even then I have had to fight the steering wheel with cross winds. With the caraban being so light I would have to guage the wind speed to decide is it safe to tow it. I still have yet to take the caravan out but should be in two weeks

 

[ProfJohnL]

Hello Crumpeteer,

Tow ratio weights are important but it far from the whole story.
It must be made clear that the 85% and 100% ratio figures are purely recommendations, and do not have any legal basis. However whilst the specific figures maybe questionable, the underlying principle supports the concept of always trying to keep the mass of the trailer as small as possible compared to the mass of the tow vehicle.

Ray makes the point that some insurers may apply ratio limits to some of their policies, but its not a universal situation. You must read the terms and conditions of you own policy to see if they artificially limit policyholders to a maximum ratio figure.

There are tow weight limits on some driving licences, If you don't have cat BE or B+E on your licence then you are legally limited to an outfit of combined MAM not exceeding 3500kg.

As Ray has suggested if the mass of a trailer is increased, there is more potential for the trailer to influence the car's behaviour. so it's always good sense to keep the mass of a trailer a small as possible.

It also important to load the tow vehicle and the caravan sensibly. Specifically with the caravan always keep the heaviest items as low down and close to the caravans axles as is reasonably possible. This reduces the caravan Yaw moments and reduce its effect on the tow vehicle.

Nose load is another factor tan needs to be carefully sorted. Your car has a maximum nose load limit of 75kg, but your caravan will also have a nose load limit. Most normal caravans have a limit of 100kg. You must never exceed the lowest of these two values. I personally aim to set the nose load to between 70 and 80% of the available limit

Again for quite complex reasons the nose load your trailer will exert on the cars tow ball is affected by the height of the tow ball. So the law requires nose loads to be measured at the same working height as when the trailer is hitched to the car. you need the caravans door step, a few magazines a pair of bathroom scales and a tape measure.

[*]Load up the car and caravan with all the luggage and passengers, couple it to the car and park it on (horizontal surface.
[*]Measure the height of the hitch from the floor.
[*]Chock the caravans road wheels so it won't roll away, and Uncouple the caravan
[*]Place the scales on the caravan step, and rest the hitch on the scales. (No steadies down and the jockey wheel must not touch the ground.)
[*]If necessary uses a few magazines under the scales to adjust the height of the hitch to match the measurement you took earlier.
[*]Then read the load on the scales That is you Nose Load.
[*]If necessary adjust the position of the items in the caravan to achieve your target nose load value.
[*]If you were well off target with your nose load, you should attempt to trim, then recouple and measure the new coupling height.

Do Not Exceed the nose load limits, as this will cause excessive load to be generated whilst towing.

The condition of the vehicles is also important , tyres should be inflated to the recommended towing pressures,and the car and trailer should be properly maintained in full working order. Don't forget that towing a caravan virtually double the cars normal loads, so proper maintenance of trhe brakes and suspension is more important than ever.

Finally driving habits, You cannot and should not expect a car towing a caravan to perform as sprightly as the solo car. Get used to things taking longer, requiring more space and time.And ultimately watch your speed. The speed of an outfit puts energy into the systems that cause instability, Deprive the instability of energy and it will reduce its effect.

This is far from an exhaustive list, but I believe these are some of the most important factors is getting a sensible towing outfit which if driven carefully should remain relatively safe.

 

[Crumpeteer]

Thanks to all who have contributed in an effort to make things clearer on the subject of tow car & trailer weights; however, this information has also got me wondering exactly what privileges my driving licence affords me.

Let me explain... I passed my driving test in 1968 (manual car) but in 1978 I received a new licence as I had a change of address. This new licence stated that I was permitted to drive vehicles in groups 'A' & ‘E’. I never bothered to check the full details of these two groups as I was only then really interested in driving a car.

Now, I've read the term; 'Grandfather Rights' which I understand to mean that whatever group/s one was covered to drive when first passing their test would be honoured even if legislation was to change later on. I am now wondering if the fact that I passed my test all those years ago (1968) I may have different rules regarding towing a caravan or whatever.

 

[Crumpeteer]

Tenpole
Good luck on your first mission. Let me know how it goes.

 

[paws]

Hi Crumpeteer,

Let me explain... I passed my driving test in 1968

This is likely to mean that your driving licence allows you the privileges of the B+E, ( grandfather rights) however don't take anything for granted... read the licence.

As its likely that you are coming up for 70 years of age fairly soon or within the next few years (or may have passed that venerable age) B+E rights continue but there are restrictions imposed on the size/mass/carry capacity of vehicles that you may drive if you elect for online 70age+renewal.

A paper renewal of the licence at 70 may be made, but subject to additional terms including medical evidence for driving these larger size/mass/carry capacity vehicles.

Please note that your ordinary private car/caravan towing privileges are not affected generally by these post age 70 requirements.

Hope this helps and does not muddy the waters for you.
Regards and Happy Caravanning
paws