VW Touareg diesel and 31 foot Airstream

[Tuco]

Originally Posted by CBWELL

Following this with interest. Have a 2009 Touareg gas, but if was a diesel would not be afraid to pull a 30' with it. Pull my 34' with a Duramax. Both vehicles weigh about the same, but the Touareg has far superior brakes. Use a Husky Centerline on the Duramax and love it. Head unit is heavy, but have pulled in some horrible winds with no problem. The combination of diesel Touareg and Husky Centerline will be a great combination. If I had a diesel in the VW would try to pull the 34!!! Chris

I must be missing something. I keep seeing people here stating that the brakes are better on these SUV's than on a modern 3/4 ton and up diesel truck. I can see where the brakes may be better, but the braking ability is not. How can a vehicle without an exhaust brake be better than one with? I took time looking for an aftermarket exhaust brake for the smaller diesels and came up empty. If someone has a link to one I would love to check it out.

[jflipping]

Thanks for all the useful info about which hitch is best!!!!

[nrgtrakr]

Touareg weighs ~5,000#, 70-0mph 177 feet
An F250 weighs - 8,500#, 70-0mph 221 feet
Stopping distance shorter, agreed.
Better brakes, do the math.

[jcl]

Originally Posted by Franswa

The sub frames are not rigidly mounted to the body, most Porsche's are split between solid rubber mounts, and hydraulic (think silicone filled) mounts depending on whether it's a cheap V6 or a Turbo. I'm trying to say that the component being used to reinforce the hitch isn't reinforcing anything, under extreme flex, it may transmit some force to the body, but your flexing the rear of the body shell likely. The point of this is just to let people know there is more to a vehicle than what the Web says.

I should start by saying that I don't know the details of the Porsche unibody and subframe, but it looks pretty similar to the approach BMW use and I am familiar with those models.

The receiver starts off as a standard Porsche part, so it is already designed to handle a vertical (tongue) load, as well as fore and aft loads relating to braking and acceleration. In Europe, those fore and aft loads relate to the use of surge brakes, and so would likely be greater than in North America. The receiver may require reinforcement due to a higher static tongue load, I don't know. But the purpose of the strut isn't any of those, it is simply to counteract the rotational moment of the WD equipment. That strut in your photo will see a vertical load, and not much else. So the question becomes, can the subframe handle a vertical load of a few hundred pounds (or many hundreds, depending on the specific setup), and what degree of motion of the original hitch assembly will be permitted due to the compliant mounting of the subframe. My guess is that the vertical load won't be an issue, and the question is whether the compliant mounts allow sufficient motion of the receiver to lead to fatigue of the rear mounting location. There is at least one more issue, that of noise transmission. The compliant mounts isolate the subframe, and the attachment may lead to increased cabin noise due to the new noise transmission path. Whether or not that is an issue would be determined on first use, I would think.

All of the above is speculation, so I would look to the company that has done several hundred of these, and see what the results have been. I would personally prefer to see the strut mounted to the unibody, all things being equal, if there was an appropriate and accessible mounting location. But if there wasn't, it appears the mounting location on the rear subframe is working for some number of owners.

Jeff

[jcl]

Originally Posted by jflipping

Thanks for all the useful info about which hitch is best!!!!

There is no best. But since we are still embroiled in whether the vehicle in question can tow the trailer in question, it may be better to start a new thread with your question.

The OP appears to have significant experience with this vehicle and a large Airstream, and stated his preference in the first post on the thread. I like the Propride myself, but I think lots of different hitches would work.

Jeff

[Tuco]

70% more mass 8500/5000
25% shorter stopping distance 221/177

Does this make the Touareg's brakes better or is it just stopping less weight? If you added 3500# to the Touareg would it stop in less than 221 ft? Did the truck use it's exhaust brake in that test? If the 31 ft Airstream in the OP's post were attached to each vehicle what would the stopping distances be (25% better for the Touareg)? On a 7% six mile grade with several corners rated between 25-40 mph and said trailer behind each, which vehicle will be closer to brake fade at the bottom? How much heat can the Touareg's brakes absorb compared to the truck on said grade? There is a lot more to braking than just the 70-0 numbers. The stopping distance's don't lie, but does that really mean the brakes are better? I still wish there was an exhaust brake for the Touareg it would only make the rig better for the OP.

[DC Bruce]

As has been noted, braking distances reflect both the brakes' ability to dissipate heat and the tires' traction with the road surface, which can vary a lot. Moreover, a lot of pickups stop in shorter distances with some load in the bed, which more evenly distributes weight over the two axles, allowing the rear wheels to have more traction. The only objective method of comparing the brakes themselves is swept brake area per ton of vehicle weight.
The point about engine braking is a good one. Lots of gasoline powered SUVs have "grade logic" cruise controls that automatically downshift to get engine braking on a downgrade in order to not exceed the set vehicle speed. That works pretty well with a gasoline engine, because, with the throttle closed, the engine is retarded by atmospheric pressure (vacuum). Since diesels run unthrottled, they don't provide any braking unless fitted with some sort of exhaust brake as is now standard in all 3/4 ton pickup truck diesels. Do the diesels in Mercedes, BMW and VAG SUVs have engine brakes? I doubt that engine braking plays any role in a 60-0 stop. But unless your trailer towing is confined to the Great Plains, the braking you should be concerned about is when your doing a long, steep downhill in the mountains. Under those circumstances differences between service brakes are much less important than the ability of your tow vehicle's engine to slow it down. And, I would add, that's why exceeding your vehicle's GCWR is a dumb idea (not that towing with an SUV always implies that you will be doing that).

[rostam]

1) A certified master technician says doing XYZ to your vehicle is not a good idea.
2) I know several folks that have done XYZ to their vehicle, and have not reported a problem (yet).
3) It must be OK for me to do XYZ to my vehicle.

If someone's thought process follows the above, then they will do XYZ to their vehicle, even if the chief designer for Cayenne/Touareg tells them its not a good idea.

[bono]

Somebody gave these numbers - I did not verified them

Touareg weighs ~5,000#, 70-0mph 177 feet
An F250 weighs - 8,500#, 70-0mph 221 feet

If you are doing 70 mph and there is somebody standing 200 feet away and you can't avoid the crash... do you think that person will appreciate F250 weight and would think: yeah, I wouldn't be hit by Touareg, but Touareg is lighter than F250, so it is OK than I am dead.

The fact is that Touareg needs less distance to stop. If it was heavier, maybe the engineers would improve the brakes. But does it matter?

Originally Posted by Tuco

70% more mass 8500/5000
25% shorter stopping distance 221/177

Does this make the Touareg's brakes better or is it just stopping less weight? If you added 3500# to the Touareg would it stop in less than 221 ft? Did the truck use it's exhaust brake in that test? If the 31 ft Airstream in the OP's post were attached to each vehicle what would the stopping distances be (25% better for the Touareg)? On a 7% six mile grade with several corners rated between 25-40 mph and said trailer behind each, which vehicle will be closer to brake fade at the bottom? How much heat can the Touareg's brakes absorb compared to the truck on said grade? There is a lot more to braking than just the 70-0 numbers. The stopping distance's don't lie, but does that really mean the brakes are better? I still wish there was an exhaust brake for the Touareg it would only make the rig better for the OP.

[Knuff]

Having driven an F150 and a Cayenne Diesel, pulling the same trailers (a 20ft FC and a 25ft FB International), I can clearly state that the Porsche brakes are by-far superior to the F150 brakes and this is true either with or without attached trailer. There is no comparison. The F-150 is a solid piece of engineering, but the Porsche is out of this world with its braking power.

[Ultradog]

Welcome back my friends, to the thread that never ends...
I keep thinking about the warning signs you see on the highways that give a recommended speed.
For example; when entering the Lowry Tunnel in Minneapolis there's one that advises 35 mph.
Now of course no one ever slows down to 35.
At any time people are cruising through at 50 or 55.
Except, some people do slow to 35. And it causes traffic snarls and backups.
So I've asked myself why do some people slow down there.
And finally figured out that the DOT who has done all the studies and knows everything said to.
And of course the DOT is never wrong and is only looking out for your safety.
Now compare those warning signs to the CGVWR that is in your door post.
Some people here just can't get past the fact that those numbers are recommended ratings. But just like the speeds on warning signs, they are not absolutes.
Millions of commuters have passed through the Lowry Tunnel at 50 to 70 MPH. And they didn't crash. So the fact is that warning sign or tow rating Can be fudged. To a point of course.
So if you are one who rigidly follows the signs and stickers that's ok.
But do try to understand those who might hit the tunnel at 50 or go over a bit on their TV.

[nrgtrakr]

Are both the F150 and Cayenne equipped with 4 wheel anti-lock disc brakes?
In the Colorado Rockies at least, vehicles are frequently found on the wrong side of the gaurd rail as crumpled up beer cans due to exceeding the recommended speed limit.

[AstroBruce]

Originally Posted by Knuff

Having driven an F150 and a Cayenne Diesel, pulling the same trailers (a 20ft FC and a 25ft FB International), I can clearly state that the Porsche brakes are by-far superior to the F150 brakes and this is true either with or without attached trailer. There is no comparison. The F-150 is a solid piece of engineering, but the Porsche is out of this world with its braking power.

Now, there is some data we can work with.

Bruce

[switz]

In the "images" under my avatar is a photo of the CanAm receiver modification to my 2007 Mercedes ML320 CDI. There are actually two pieces of the 2" square receiver tubing welded together to get things lined up. The lowered the suspension air tank on 2" stand offs to clear the reinforcing steel.

[2012FB]

I just love this thread!

Having driven/owned a 2012 2500HD, a 2014 ML350 Bluetec (fully outfitted by CANAM) and a 2015 2500HD back to back to back, pulling the same trailers, (a 2012 25FB Twin and a 2015 30' Bunk), I can clearly state that the 2500HD in tow mode with exhaust brake turned on, is more stable, has better control under heavy breaking, pulls effortlessly at the posted speed limit up and over the highest mountain peaks without strain, or any heat indicator moving whatsoever, in cruise control will automaticly control the down shifts and exhaust brake so that going down a 6-9% grade does not require the use of TV or Trailer brakes, and all things considered mileage is about the same. Panic braking includes very hard and fast downshifts with the engine brake fully engaged. This is with maybe a 1,000 pounds of gear in the bed, and bikes on top of the truck bed.

I too certainly LOVED towing with the ML350 who would not. It is plush, quiet, comfortable and when not coupled to the trailer is about as good as it gets for a daily driver, but it is not designed to do so, nor in my humble experience the safest vehicle to tow a 25' plus trailer with.

[SteveSueMac]

Originally Posted by Ultradog

Welcome back my friends, to the thread that never ends....

I'm so glad you could attend - come inside come inside! 😄

Originally Posted by Ultradog

So I've asked myself why do some people slow down there.

And finally figured out that the DOT who has done all the studies and knows everything said to.

And of course the DOT is never wrong and is only looking out for your safety.

Now compare those warning signs to the CGVWR that is in your door post.

Some people here just can't get past the fact that those numbers are recommended ratings. But just like the speeds on warning signs, they are not absolutes.

Millions of commuters have passed through the Lowry Tunnel at 50 to 70 MPH. And they didn't crash.
...snip...

Interesting points - why people may or may not slow down could be a function of trust in authority, risk tolerance (calculating less than X% of folks who drive get in accidents so I'll take that risk) and/or bent toward conformity to community rules.

Whether or not the DOT has it "right" (what really is right anyway - is it 35 or 37.684 mph that is the actual point and does that change if your vehicle is 4000# vs 80,000#, etc), if those are the rules, one decides whether or not to adhere.

And in certain contexts, speed limits on signs are absolutes - for example, if an officer is in the area with a speed gun and catches you at something over the limit - s/he can certainly write a ticket (not as bad a consequence as an accident, but a negative result for exceeding the limit). And even there, we can see randomness. Are you ticketed for 1 over, 5 over, 10 over, and are those in actual MPH or % over the limit?

Last - the point about not having a crash - it's a little like arguing "I've never worn a seatbelt in 35 years of driving and I've never needed one." Here, the immutable laws of physics will exact a price IF there were a crash. And that's perhaps another reason folks choose to adhere to the numbers. You never need it, unless you need it 😄

[Echelon73]

I have also been following this thread off-and-on myself. One thing I have learned is that people on this site are very concerned about safe towing, which is awesome. Everyone has a different opinion of what safe towing is though. I towed boats (up to about 6000lbs) for most of my life and never had a problem with my 1/2 ton trucks, but after a season of towing my 30fb with a 1/2 ton I decided to get a 3/4 ton diesel. Yes, it is way more truck than I will ever use, but the whole setup feels much more stable and safe to me. I agree that you should try very hard to stay within manufactures specs, but in the end it really comes down to having a rig that feels stable and reacts the way you expect it to. For me that is a 3/4 ton diesel with an exhaust brake. For others that may be VW Tdi SUV. The key in my mind is to have a complete rig that handles well for you and feels very stable and under control in all conditions. Some people on this thread feel overwhelmed driving and maneuvering a 3/4 ton even without a trailer, while others feel like smaller vehicles just get pushed around too much with a heavy trailer. My point is, pick something that fits your needs and driving style, try to keep it within manufactures specs, set it up properly, and enjoy your travels.

[derf]

Echelon "Ditto that" I can't figure out how to put the 2 bikes, 2 kayaks, gas barbecue, honda 90 trail, 2 grand kid bikes, campfire wood, bucket, shovel, axe, spare propane tank, paddle board, 2 beer coolers folding table, five people in a TW Tdi SUV. Maybe someone has a photo of one?

[dkottum]

If anyone comes here to learn about Touaregs and Airstreams, it's a remarkable disappointment.

We already know why it can't be done, it's been reposted several times a week in the hijack of other threads. Many of us come here to learn how it can be done.

Hundreds are towing Airstreams with their Touareg, Cayenne, or Q7. Including Tino, the o.p. These are not laying in heaps along the roadside. Perhaps someone can explain that.

[mefly2]

Specific question...
Please post your experience with VW USA with regard to warranty claims coverage due to power train damage or failure. We like the VW Touareg, but have been told by two different dealers' service managers that VW USA will NOT cover ANY damage to the powertrain caused by pulling our 25EB. Apparently, they can read the vehicle computer to see the load parameters.