[Deli Llama]

Yes I totally agree on caravan engineers. I upgraded from my Prado to the Touareg because I needed better tow capacity for my next caravan which will be full height no pop top. Every single van out there nowadays is 3500kgs GVM and I see people towing with dual cabs that just bend their chassis. I am encountering issues with the Touareg that I was not expecting but I will overcome them with everybody’s help here I’m sure. Perhaps I should have gone with air suspension but I was put off by the extra complexity and inevitable failures that would happen out whoop whoop

Are you sure that you won't be exceeding the maximum rear axle load with such a heavy caravan?

 

[gatkins]

Stiffening up the rear springs, or lifting the car or tow hitch may make it all look better BUT..... that is all cosmetic and may not address the issues.
In Australia even if you use a WDH, the car weights are assessed without the WDH tensioned.
As I discovered a few days ago when I had my whole rig weighed professionally at each wheel it quickly goes pear shaped on rear axle limits when towing with a Touareg.
My setup was 1100kg below the allowed GCM (6415kg) but I had still exceeded the allowed rear axle load limit by 90kg which on my 7P with air is 1530kg
In the car was just me (125kg ) and a full tank of diesel (100 litres), no luggage or extras in the car, the caravan was heavy on the tongue at 320kg, ok I can shift load off the tongue easy enough to get back to 280kg but I still need to add partner and dogs to the car (another 115kg total)
For towing in Australia where the authorities are now beginning to look closely at axle load limits and overall limits this poses issues as the penalties are tough and insurance may not cover you if overloaded.

 

[Deli Llama]

Yes. I agree. The rest axle load is usually the first limit to pass.

 

[Wizz954]

I'm just going to add my 2c here and ask if changing the car over to one with air suspension and stock tow bar might also be an option? A lot of time and expense to go to with new suspension, lift kits, etc etc. Is there something special about this car? Air suspension will fix your problems, and when you upgrade the toy hauler (as you suggest) you won't run into a whole new set of issues. You'll also gain the extra HP as air suspension usually accompanies the 180kw engines. Anyhow, at the very least I'd try a WDH as they will help, but I'm not certain they'll get rid of that much sag.

I hear you. I got the car very cheap and willing to put money into it for now. By the time I’m finished it’ll owe me $32k which is still a bargain.
I agree air suspension would be nice but I’d want a much younger car if it had air suspension for reliability.
I have a stage 2 tune on mine which puts it at 200kw and 550Nm so it will pull nicely. The $$$ I save on a car will go towards the new caravan which ain’t gonna be cheap !!! I’m just happy not having to buy a similar year Landcruiser for $85k that people are asking! The Touareg is a bargain in comparison even with the mods.

 

[Solandri]

Getting the trailer level isn't as important on a single axle trailer. The forces transmitted are nearly the same as a straight trailer, just at a slight angle due to the cant at the trailer ball. The cosine of small angles is nearly 1 so not much difference. e.g. cos(5 deg) = 0.996, so tilted at 5 degrees there's only a 0.4% deviation from a straight trailer. Proper weight distribution fore/aft of the trailer's axle is more important (to prevent sway).

Getting the trailer level is crucial on a dual axle trailer. The angle the trailer sits at determines the weight distribution between the trailer's front and rear axles. If it's flat, it's close to 50/50 (after subtracting the weight supported by the hitch). As you tilt it up or down, you shift the weight towards the rear or front axle respectively. This can lead to you exceeding an individual axle's weight rating just having the trailer hooked up to your car. e.g. If the hitch were high enough, the front wheels would be off the ground (zero weight), and the rear wheels would be bearing all the weight. If you look on the trailer's spec sticker, it should tell you the optimal ball height.

I really wish I had an air suspension for this reason, since hitch height varies with load and each (dual axle) trailer has its own optimal height. But it was no longer an option in the U.S. when I got my Treg. I had to guess how much sag there would be and buy a ball mount with a rise to counteract it.

A WDH compensates for this by more tightly coupling the trailer and tow vehicle in pitch. But does so by transmitting torques through the hitch, which VW never considered when designing the hitch and frame. Hence their recommendation not to use a WDH - they literally don't know what will happen. Based on the numerous user reports of using a WDH and lack of user stories of the rear of their car's unibody construction bending, it seems to work. But just be aware that's all anecdotal evidence, and no engineering calculations have been done to verify it's OK.

 

[Wizz954]

Sounds like the rear axle load is the thing to watch. Does anyone know the load rating? I don’t have a manual with the car. Where can I get it weighed to check I’m not overloaded?

 

[Deli Llama]

I don't have a 2013 model. It varies from model to model. I think the value for my 2015 model is about 1530 kg?

 

[Wizz954]

I don't have a 2013 model. It varies from model to model. I think the value for my 2015 model is about 1530 kg?

2015 is different but I would imagine mostly cosmetic. Is yours steel springs or air suspension?

 

[Deli Llama]

Air suspension. I thoroughly recommend it.

 

[gatkins]

Several Pages from the Touareg manual describing Weights for various models

 

[Wizz954]

Several Pages from the Touareg manual describing Weights for various models

Thanks for posting those pages. Mine has rear axle limit of 1530kg so next question is what’s the load on the rear axle unladen? That will give me some idea of what payload is possible.

Kerb weight is 2153kg, would it be reasonable to assume 55/45 weight distribution? 968kgs on rear axle? That leaves 562 kgs of payload over rear axle, take away 280kgs towball weight and 80 kgs of fuel, leaves 202kgs for rear passengers or 400kgs in the cabin spread over both axles.

 

[gatkins]

I can tell you that I had mine professionally weighed a week ago
GCM van & car 5300kg
Rear axle came in at 1630 (yes 90kg over)
That includes;

• 324kg on the ball ( yes too much )
• 100 litres of diesel
• 1 driver (125kg)
• no luggage or passengers

That should give you an idea of how tough it is to manage

 

[Wolfy]

Unfortunately it doesn't quite work that way. Because of the lever effect of the towball overhang behind the rear axle, more than the towball load is transferred to the rear axle, with a corresponding reduction on load on the front axle. I believe the weight factor is 1+ overhang / wheelbase. For the CR with 2895 mm wheelbase and 1119 overhang, about 1,4 times the ball weight goes onto the rear axle, so 280*1.4 = 392kg. The ONLY way to get an accurate answer is to have your rig weighed with what you carry in the vehicle (fuel, driver and co-driver, anything you'll carry in the car) to establish accurate axle weights, and then repeat it with the van hitched up. There is any number of mobile weighing services that do exactly that. Better to spend a few hundred on that than cop a fine and a defect that would stop you continuing your journey with the van hitched, and worst cased invalidate your insurance if you had a mishap the insurance company could claim was load related.

 

[Wizz954]

I was so convinced with the GCM figures that the Touareg would be a good tow vehicle and everyone says it is! This rear axle weight limit seems to be a much bigger limitation and you may as well forget GCM, GVM. I’m now wondering if I reconsider my choice of tow vehicle or will it all come good when I upgrade to a twin axle van with lower towball weight? I fear I’ll still be in strife with towball weight as the new van would be close to 3500 GTM. I’d want to be fully laden with 4 passengers…

 

[gatkins]

I forgot to say…. I was 1100kg under GCM

 

[Wizz954]

I forgot to say…. I was 1100kg under GCM

Yep I struggle with the GCM. How do they come up with that rating when it’s clearly not achievable?

 

[gatkins]

Achievable if you have 2 passengers each 75kg, no luggage, half a tank of fuel and no more than 280kg on the ball
Then you can tow 3500kg
I LOVE this Touareg, and will manage by shuffling loads to reduce TBM
Already travelling with nothing but 40kg of dogs in the car ( oh and wifey who apparently doesn’t weigh much at all 😀)

 

[Wolfy]

I was so convinced with the GCM figures that the Touareg would be a good tow vehicle and everyone says it is! This rear axle weight limit seems to be a much bigger limitation and you may as well forget GCM, GVM. I’m now wondering if I reconsider my choice of tow vehicle or will it all come good when I upgrade to a twin axle van with lower towball weight? I fear I’ll still be in strife with towball weight as the new van would be close to 3500 GTM. I’d want to be fully laden with 4 passengers…

IMO, while Australian van manufacturers and caravanning media remain fixated on 10% ball weights and that 300kg plus ball weights are ok, the Touareg (and most unmodified dual cab utes, Prados and Cruisers) will struggle to tow anywhere near their headline weights while carrying any internal payload without overloading rear axles. For 2t+, the Touareg needs to tow vans designed closer to Euro specs of 5-7% tow ball download. More sensible weight distribution at tare also means that ball load doesn't increase as much from tare to loaded.

 

[Deli Llama]

Yes. I think that if one looked at all the available tow vehicles' the rear axle load would be the limiting factor. It's not just the Toerag that has the problem.

 

[gatkins]

My van is a 2016 model and heavier on the ball at tare than some,
many of the newer vans are quite light on the ball to the extent that they are sometimes perform poorly on their first trip home from the dealers whilst travelling empty.
I feel the Touareg whilst having and excellent GCM it has the lowest rear axle load of common tow vehicles in Australia
comparison below (There may be some minor variations between models but for discussion this should do)

	Tare Mass	Gross Vehicle Mass	Gross Combination Mass	Towing Capacity (braked)	Towing Capacity (Unbraked)	Maximum Towball Download	Max Roof Load	Max Axle Load - Front	Max Axle Load - Rear
2018 Jeep Grand Cherokee	2327 kg	2949 kg	6099 kg	3500 kg	750 kg	350 kg	68kg	1452 kg	1678 kg
2017 Volkswagen Touareg	2153 kg	2860kg	6415 kg	3500 kg	750 kg	280 kg	100 kg	1380 kg	1530 kg
2021 Isuzu D-MAX	2035 kg	3100 kg	5950 kg	3500 kg	750 kg	350 kg		1450 kg	1650 kg
2021 Isuzu MU-X	2175 kg	2800 kg	5900 kg	3500 kg	750 kg	350 kg		1450 kg	1650 kg
2021 Mitsubishi Pajero Sport - Exceed	2110 kg	2775 kg	5565 kg	3100 kg	750 kg	310 kg	80 kg	1360 kg	1600 kg 1840 kg (Triton)
Toyota LC200	2740 kg	3350 kg	6850 kg	3500 kg	750 kg	350 kg	200 kg	1630 kg	1950 kg
Toyota Prado	2240 - 2305 kg	2990 kg	5990 kg	3000 kg	750 kg	300 kg
2021 Ford Ranger	2099 - 2278 kg	3200 kg	6000 kg	3500 kg				1480 kg	1850 kg
2021 Ford Everest	2384 kg	3100 kg	5800 kg	3000 kg	750 kg			1480 kg	1750 kg