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Hi all,
HI want to try and identify and compare any region specific different towing "tongue weights" for the Macan. If you look up your drivers manual it will tell you the towing capacity and tongue weight. Tongue weight is the load on the towbar ball or weight sitting on the rear of the vehicle.

Why compare tongue weights? Well, I gather since about 2016 Porsche has produced an OEM towbar rated at 200kg (440 lb). This OEM towbar is recommended for my My 'Australian' Macan S MY2015.... however the drivers manual says only 96Kg (210 lb) !.

The towing capacity (what you can haul or tow behind the vehicle) for Macan varies with source and model but around 2000kg to 2400kg (4409 lb - 5290). These kinds of weights would generally place around 200 Kg (440 lb) load on the back of the vehicle (following the 10% rule). So it doesn't add up unless the tongue weight for the Macan is really 200 Kg (440 lb) and NOT 96Kg (210 lb).

I am wondering if different countries may specify different tongue weights irrespective of the Macan's inherent capability. For example with slower speed limits you could get away with lesser tongue weights

Thanks
David
 

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Tongue weight recommendations and limits vary a lot between the U.S. and Europe for reasons that are fuzzy. I’m not sure about Oz. Europeans seem to run much lower tongue weights as a percentage of towed weight, about 6-8% IIRC, while U.S. recommendations are generally 10-15%.

VWAG straddles the two standards, using stickers on hitches for American vehicles that state tongue weight limits of either 8% or 10% of max towed weight. My Cayenne has a 616 lb limit for 7700 lb towing capacity (8%) and I’ve juggled loads fore/aft of trailer axles to live with that because I towed no more than 6000 lb. But in some cases VW sent Touareg owners new stickers with a 770 lb (10%) limit.

One of the best resources for towing is the Airstream Forum. It includes a 75-page thread dedicated to towing with the Cayenne-Q7-Touareg platform, which includes generally helpful advice as well as discussions of the international standard discrepancies described above. The consensus on that thread seemed to be that slower towing speeds in Europe don’t require the higher tongue weights commonly used in America, but I never saw documentation of that. Are towing speeds really lower in Europe? Weight Distributing hitches are common in America but not in Europe, adding to the confusion. Good luck!
"What does your Macan Driver's manual state for towing Tongue weight/Drawbar weight?".......That was the title of a new thread/post that got moved here instead but didnt get transferred with the title. .....thanks for reply. Yes, like you, the reasons for the whole tongue weight discrepancy seems to be a bit fuzzy and I have also come across the ""strict 55mph towing speed" in Europe and generally 5% (not 10%) of tow capacity.

My concern was/is if the manual states something that relates to vehicle capacity like a 210lb tongue/drawbar weight then it would be foolish to exceed it.IF on the other hand, manuals for the same Macan have different specs in different countries then one assumes it is a geopolitcal/local variance and not a strict engineering tolerance.

The 2015 Aussie manual spec of 210 lb also may just reflect a European standard that got translated into English for Australia?

Australia like N.America has higher towing speeds (60mph mainly) and most seem to recommend the 10 - 15% tongue weight.

Also, Are North Americans and Aussies (and Europeans/UK) actually towing up to the maximum towing capacity with whatever tongue weight?

So, I am interested whether N.American Macans come with a Drivers manual which specifies tongue weight (drawbar) of 210 or 440 lb ?

Thanks again
 

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It appears they’re using the 10% rating. It remains unclear whether this is for towing performance (sway control) vs structural reasons, so it’s best to assume it’s a firm structural limit. CanAm RV in London, Ontario, Canada seems to be a leader and resource for German SUV towing in North America. They do hitch reinforcement work and are trusted by the Airstream community. They sometimes reply to email questions as well.

Keep in mind your tongue weight includes everything hanging off the receiver, including the shank and ball. It’s also wise to minimize cargo as much as possible. It’s better carried over the trailer axle than behind the back seat. The 440/4400 lb rating gives you loading options, especially if you’re not pushing the 4400 lb limit. Good luck.
Thanks @lyricgskills !! This is exactly what I suspected and hoped for, a 440lbs/200kg Towball mass (Tongue/Hitch/Drawbar weight).

Thanks @Dkayak I am confident now that the lower figure of 210 lbs in my Drivers manual is a European recommendation for towing performance/speed and NOT a structural limitation of the Macan S rear chassis. My MY 2015 drivers manual also has a 2400kg ( 5290 lbs) higher towing capacity which I am aware was downgraded in subsequent models. This and the fact that the OEM Porsche towbar for my car comes with the higher rated tongue weight of 440 lbs and N.American drivers manual 440 lbs spec all point to a chassis that can take the weight.

Yes, good point to consider everthing that loads down and/or creates a moment (torque) behind the rear car axle.

I came across this excellent video considering weight distribution and hitches if you are into the maths/physics....some interesting conclusions....Physics and Maths of WDH
 

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Haha yes it would be tough going using a long pry bar!

As an engineer I'm guessing you'll appreciate the maths explained in that referenced video. I did some undergraduate physics as part of another degree (Medicine). My current physics teacher is some guy called Richard Feynman...:ROFLMAO:...you can do his Caltech course online. I love his stuff like "Surely You're Joking Mr Feynman ! Adventures of a curious character - A different set of tools. Unfortunately my Math skills fall way below most physicists and engineers.

My limited understanding of how WDH work is that in order for the nose of the trailer tongue to pivot up or down (clockwise or anticlockwise in the sagittal (longitudinal) plane) it would have to compress the bars. This has a spring effect creating a moment resisting that pivot rotational movement. Effectively, this creates a semi rigid coupling of trailer to car in the vertical plane. This effectively extends the tongue of the trailer as if the frame of the car has become a forward extension of the tongue of the trailer. The weight is then sitting more evenly distributed between all wheels touching the ground, including the trailer. The price appears to be a lack of articulation that comes with a semi-rigid 'joint'.. less good for off road or uneven surfaces. I wish I could ask Mr feynman but he is no longer taking questions !

I have adaptive Air suspension (PASM) and some SUV makers recommend against WDH if they have air. I dont know what the Porsche verdict is. I will at least get levelling with AS and some expected minor/ less dramatic weight 'shift' that comes with change of pitch. Probably the most effective weight distribution principle is to get the load positioned correctly.
 

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@Dkayak
Thanks for posting these real-world figures as an example how weight distribution hitches effect load.

From the raw data, and I could be missing something glaringly obvious but it seems that in the 1st scenario where the springs were tensioned by the installer, there was a net transfer of 80 lbs from rear to front axle of the tow vehicle with the WDH connected. Interestingly, the weight on the trailer axle did not change, remaining 5360 with hitch connected or disconnected.

In the 2nd scenario, with the springs tightened up to properly level the vehicle, the tow vehicle front axle gained 300 lbs and the rear axle lost 400 lbs (100 lb difference between 300 and 400) . Interestingly, the weight of the trailer axle did not change at 5240 lbs with hitch connected or disconnected.

So somehow there is 100 lbs to be accounted for. If you look at measurement error of the scales when comparing the same mass there is up to 40 lb error in tongue weight, 60 lb error on any individual axle, 80 lb error in measuring the same tow vehicle, and for the gross combined mass a 200 lb error (10 860 versus 10 660).

So if I was to guess, I would say in the 2nd scenario there was a weight transfer of 300 lb and the unaccounted for 100 was measurement error in the scales themselves.

It does make it hard to interpret when there is this amount of precision error in the test device.

What mostly surprised me is that in neither scenario did the weight over the trailer axles change. Trailer axle weight remained 5360 in the 1st scenario with hitch connected or disconnected, and in the 2nd scenario 5240 with hitch connected or disconnected. I’m not sure where you’re getting the 140 lb weight transfer to the trailer in the 2nd scenario?

That’s okay, I probably missed something. One of the reasons I did not do a dual degree which included physics is because a) I’m not totally crazy and b) the math started giving me headaches and there were much more interesting ‘figures’ walking around campus :love:!

All that said, it looks like the WDH is doing its job both quantitatively (even given the precision error between measurements) and qualitatively with subjective feel. I was a little sceptical at first when I saw an Internet video from the hitch maker who essentially did the same test as yourself but the figures were to my understanding grossly spurious. I won’t reference the video here but there were significant discrepancies between repeated gross combined weight (when I calculated the weight over all axles) which I understand is impossible unless for example you weigh the rig on different planets :ROFLMAO:.

So congrats, I think you have gone above and beyond what most people would do and the rest of us can benefit from your experiment. The experiment does agree with the theory and as my friend Feynman says, “if it disagrees with experiment, it is wrong.”

Cheers and thanks again

David
 

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After a fun 2021 COVID era experiment, we learned a lot and know better what we’ll buy if we ever decide to re-enter, with either a towed teardrop trailer or a Class B van. This would be lighter, more aerodynamic, and better built/finished than what we had. Towable easily by a Macan too.
Those "Little Guys" look great. Unfortunately they don't appear to be available in Oz. There is someone making "Little Guy" pods here weighing around 600kg (1300 lbs) but I was also looking at an Adria brand tear drop design caravan from Slovenia and it has prompted me to search other "tear drops". I want to keep (unloaded) weight around 1200 to 1300 kg (about 2800 lbs).

In Oz, campervans seem to be disproportionately expensive and motorhomes, while relatively better value for money,are expensive and probably too big. I gather its also not possible to access all our National Parks in a motor home.
 

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The blue shaded cells are the raw axle weight data from the scales. You’re looking at the white cells with TV and trailer weights derived from the scale data. TV = sum of two axles. Trailer = tongue + axle. These are the changes when load bars were installed. Front; 2548 to 2840 (+300). Rear: 3480 to 3040 (-440). Trailer: 4640 to 4780 (+140).
Oh ok, yes, I missed the blue cells figures for Trailer: 4640 to 4780 (+140). That makes sense.
I dont understand the white cell derived Trailer figures w/o bars attached, Tongue 600 + axle 4640 and w/bars attached Tongue 600 + axle 4780, both = 5240. Its this last figure that threw me not being changed.
It also raises the question how you measured or derived tongue weight once hooked up to trailer (or was it measured unhitched)?
 

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Trailer weight = combined weight - tow vehicle weight
Trailer weight = 10,660 - 5420 = 5240

Then, Tongue weight = trailer weight - trailer axle load
Tongue weight = 5240 - 4640 = 600

And tongue weight is determined without load bars in place. You can also buy a special tongue weight scale to directly measure it (unhitched) as you move your load fore and aft or change what you bring along, but this derived method is quite precise too. Just keep the shank and ball off for your first scale pass so their weight doesn't get included in the tow vehicle weight. You can extract a lot of information from those 3 passes over the scales.
Hi @Dkayak

Edit:- I initially struggled with this as it was more intuitive to me to derive tongue weight by
calculating Hitched Tow vehicle weight (measured) – Tow Vehicle Weight Unhitched (measured) rather than the steps you outlined. Thinking it through I see how your method provides an alternative method.(y)Thanks
 
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