Audi RSQ8 towing 27' Globetrotter... Are we nuts or in love?

[farrel509]

First, let me state I am a mechanical engineer.
Next, let’s assume that Audi’s engineers have calculated and tested the chassis of their vehicles in a way that will keep them out of multi-million dollar lawsuits. These engineers must follow the SAE J2708 guidelines to even say what an Audi Q8 can safely tow.
Lastly, I’ve corresponded with CAN AM about some of their tow modifications in the past. (Airstream 27 pulled by a Dodge Minivan??) They beef up the hitches and/or attachment points of vehicles with no regard for frame or unibody construction strength. They calculate nothing. Their reply to my questions and concerns were, “It hasn’t broken yet!”
Factors of safety are usually quite high for vehicles performing human conveyance. So, you may be able to get away with 1000 pounds load on a 770 pound attachment point but remember, there is such a thing as fatigue.
I suspect CAN AM may slow down making modifications to factory hitches when the lawyers finally show up pounding on their door.

[Seanlb]

My comments are really made with the best of intentions.

It seems that the only authority whose opinion should really hold credibility is the group of folks who build that vehicle — and as an Audi TDI owner myself, I know what VW/Audi has approved their vehicles to be capable of.

I wouldn’t think of pulling that much weight with a unibody midsize, especially without weight distribution.

[jcl]

Originally Posted by farrel509

First, let me state I am a mechanical engineer.
Next, let’s assume that Audi’s engineers have calculated and tested the chassis of their vehicles in a way that will keep them out of multi-million dollar lawsuits. These engineers must follow the SAE J2708 guidelines to even say what an Audi Q8 can safely tow.
Lastly, I’ve corresponded with CAN AM about some of their tow modifications in the past. (Airstream 27 pulled by a Dodge Minivan??) They beef up the hitches and/or attachment points of vehicles with no regard for frame or unibody construction strength. They calculate nothing. Their reply to my questions and concerns were, “It hasn’t broken yet!”
Factors of safety are usually quite high for vehicles performing human conveyance. So, you may be able to get away with 1000 pounds load on a 770 pound attachment point but remember, there is such a thing as fatigue.
I suspect CAN AM may slow down making modifications to factory hitches when the lawyers finally show up pounding on their door.

I am also a mechanical engineer.

The SAE standard is voluntary. They don't have to follow it at all. And you confuse the issue by adding the word safety in.

It is not a performance standard. It is a test standard. It specifies a set of standard conditions so that manufacturers can test their vehicles under those common standards, and thus consumers can compare ratings from one manufacturer with the ratings of another manufacturer. It is a comparison shopping tool. Where it can become influential on safety is when some US manufacturers, who were in a type of arms race to constantly increase their tow ratings, had to rein it in a little. This applies most to product classes such as pickup trucks, where higher tow ratings are seen as a marketing feature.

For Euro SUVs, the most common benchmark tow rating is the break point where users would require different (more stringent, more expensive) licensing for their tow vehicle and trailer. It is a metric figure, but translates to 7700 lbs. For a Euro manufacturer to rate to that figure (and they nearly all do) they test to that figure. End of story. They don't test at a higher trailer weight, and don't claim that the figure is the ultimate capability of the tow vehicle, they see no reason to go higher. They simply use a convenient figure that consumers look to.

If we wanted to use the SAE tow rating test standard to determine what is safe, we would have to go a lot further than the SAE test standard currently does. For example, we would consider wind loading and sway. We would use test trailers that more closely approximate travel trailers. We could test the trailer brakes, eg we would actually connect them, and we would test the tow vehicle brakes at more than 20 mph on a flat road. We wouldn't make the hardest braking test to overcome the parking brake test. Those factors could provide some guidance for those who want to rely on the SAE standard as an indicator of what is safe or not. Until then, it is convenient in that we can say that a Ford was tested under the same conditions as a RAM or a GM. But don't assume that those are real world conditions, that would be very dangerous and would lead to the unfortunate situation whereby people purchased tow vehicles primarily by their tow ratings, and subsequently paid less attention to the importance of towing setup, since "it is rated for that".

[Russ Abbey]

My only concern is the safety of this. Also what will the insurance company say to hauling a trailer over on the tongue weight, possibly over weight also, are they going to cover it? If and it's a big if here. Next can you live with yourself if the trailer got away form the tow vehicle, due to stress on the tow rig, and someone got hurt or worse? I had a wake up experience when we first got our 32 foot Excella. The trailer, due to weather decided it wanted to be in front of me going down the highway. That was one of those wild rides you never want to have again thru we went to a higher tow capacity vehicle. And I had no choice either. I loved my F-150 Pickup, but the Wife said never again did she want to see me that white knuckled driving us around. Needless to say that when we got home from our trip we bought a new to us F-250 with all of the bells and whistles on it. Very nice and even better looking than my F-150. However, it also has the diesel in it and it does cost more to operate.

That is my story, and just food for the original poster to think about. It's never fun to have after talking to my insurance company rep here in town say that if we had had an accident with that truck, any expense might have not been paid due to the truck not covering the actual weight. I weighed myself on a CAT scale and yes, my hitch weight was over big time. After that when we got the F-250, the first place I hit was a scale with the trailer. Weighed it with the truck, and then pulled the truck out form under the trailer to check the hitch weight. We also only take what is necessary to camp, but our trailer was said to only weight 5300 pounds too. "They" lied", as it weighed so much more after LP, water, dishes, pans and food was put in it was way over the limits.

73 (Ham radio Talk for best regards)
Russ and Chris Abbey
Floyd County, Virginia

[matthewk]

Originally Posted by KelDarBerg

Hi, unfortunately I think you are in trouble and in the same boat we are with our Tow vehicle. As new airstream owners we were undereducated on ALL of the actual weights that mattered, and have learned from the school of hard knocks that even our Ram 1500 is insufficient by the numbers for the Globetrotter27FBQ:-(

We made the mistake of trusting 2 numbers. One was the towing capacity of the vehicle which is really a false sense of security as it is only one of many numbers that need to be calculated. The second as mentioned by others is the actual tongue weight. For our globetrotter loaded for travel with plenty of unused storage and empty tanks, we weight 7000lbs on a CAT scale. But our hitch weight is 970lbs, 100 more than published.

The numbers you need to pay attention to:
1) Towing Capacity. You are technically good there at 7700lbs being greater than the 7600lbs GVWR of the trailer.
2) Hitch weight. You are probably in trouble here but to know, you need a trip to the CAT scales plus a tongue weight scale (you can do it without the tongue weight scale, but the math gets a bit tricky for sorting it out the first time on your own). Even with a weight distribution hitch properly configured , I can only get the tongue weight down to 800lbs on our Ram. I think it’s because I also have air suspension and I think it fights to counteract the WD hitch. In theory you should be able to get down to 2/3 of the dead hitch weight but I can make it happen. At best, 2/3 of 970 is still over 600lbs.
3) Tow vehicle payload/GVWR. This is a hidden kicker. I don’t know what your payload is, but it should be on your door sticker. Different manufacturers include or exclude fuel. Regardless, you need to take the weight of passengers, vehicle cargo, fuel, AND the weight of the WD hitch weight (plus the hitch itself) and make sure you don’t exceed GVWR. This one is actually easy to figure out. Load up like you are going on a trip ad take the whole rig across a CAT scale. The sum of the front and rear axel weights Is the fully loaded GVWR of your Audi. I hope it is under the sticker value, but sadly I would bet it is not.
4) Gross Combined Weight Rating (GCWR). This is what the Audi is rated for total rig configuration. Again this is an easy number to get rolling across a CAT scale, but will also bet it is not within range. When towing capacity is stated it is usually assuming just a driver. If you take the GCWR and subtract out the Towing capacity, it is very likely to be a number quite a bit smaller than the tow vehicles GVWR.

I have researched more tow vehicles than I care to recount that will tow our globetrotter and meet ALL of the above specs and the list is decidedly short and mostly contains 250/2500 class trucks:-(.

Will your Audi tow it? Sure, you already proved you can. Do people tow with even less? Yup, seen it and scratched my head how.

It depends what you think exceeding any rating number does to your ability to claim warranty repairs, what the likely stress on the tow vehicle is, and what you feel your exposure is to liability or lack of coverage should you ever be in an accident/incident and you were exceeding a spec. Additionally if you are knocking up against limits, you need to think about what that does towing through sub-optimal conditions like an unexpected snow or through mountainous terrain.

Good luck, unfortunately this is not information I was easily able to find or was educated on before we bought our Globetrotter.

The bolded statement above is inaccurate. You cannot reduce hitch weight with a WD hitch, you're only moving how the weight is distributed to the axels. Also, when you use a WD hitch you have to add the entire weight of the hitch, drop shank, bars and receiver to the tongue weight of your trailer so it actually goes up.

The math on the CAT scales works like this.

First measurement (M1): tow vehicle only, remove hitch from receiver, roll on to the scales. Three numbers: Front [F1], rear [R2] & total [T1]

Second measurement (M2): Tow vehicle and trailer, roll on the schedules.. Four numbers: Front [F2], rear [R2], trailer axel(s) [TA2] & total [T2].

(F2+R2)-T1 = Tongue weight
F2-F1 = Front axel loading
R2-R1 = Rear axel loading.

[Iowa Bumpa]

I have seen it all since 1986. While at the Airstream factory, I have witnessed folks like you who think their Mercedes, BMW, Audi can pull their trailer. They are correct. Just about anything will pull a trailer down the highway. My son-in-laws father spent 40 years with the Iowa Highway Patrol. He told me that most RV accidents occur when you are run off the road, avoiding animals, other cars, etc. Your tow vehicle should be one that will first protect you in case you are going down an embankment, a ditch, a roll-over or other. We are on our 5th F-350 Crewcab - 8’ box - 176” wheelbase. The braking is phenomenal. The cab construction is heavy duty. Of course we have no problem pulling, but our main concern is what if? I see people pulling huge toy haulers with 1/2 ton trucks. Sure, it will pull it but what happens if you need to stop really quickly? This is my point. I’m sure you love your car and it will pull your Airstream. But consider what the highway patrolman told me - buy a tow vehicle that will save your life in case you get run off the road, or you need to stop quickly, or you do run into an animal, an excursion into a ditch or field or more. Your choice! My two cents!

[farrel509]

Ok, so it’s voluntary. So what if every manufacturer selling vehicles in the US uses it to determine tow capacity. This still doesn’t resolve the, “it hasn’t broken yet” as an sufficient method of determining the structural integrity of a home-grown factory hitch modification when there will be humans sitting in the tow vehicle. Voluntary standards must mean something otherwise, what’s the point?
You know, you probably could come up with a way to tow an Airstream with a Vespa sufficiently modified for the task. But would it be a good idea just because there is no enforced standard for it?
Without the stated ratings from manufacturers following stress and crash testing, where would you suggest we start?
I think, actually we agree on this except you decided to sneeze when you read “safety standard.” I also think we agree that modifying the factory Audi hitch with a bunch of steel and a welder in an effort to increase the hitch weight is not anything an engineer would recommend without a ton of analysis. The limiting factor may not be the hitch at all.

[jcl]

Originally Posted by farrel509

Ok, so it’s voluntary. So what if every manufacturer selling vehicles in the US uses it to determine tow capacity. This still doesn’t resolve the, “it hasn’t broken yet” as an sufficient method of determining the structural integrity of a home-grown factory hitch modification when there will be humans sitting in the tow vehicle. Voluntary standards must mean something otherwise, what’s the point?
You know, you probably could come up with a way to tow an Airstream with a Vespa sufficiently modified for the task. But would it be a good idea just because there is no enforced standard for it?
Without the stated ratings from manufacturers following stress and crash testing, where would you suggest we start?
I think, actually we agree on this except you decided to sneeze when you read “safety standard.” I also think we agree that modifying the factory Audi hitch with a bunch of steel and a welder in an effort to increase the hitch weight is not anything an engineer would recommend without a ton of analysis. The limiting factor may not be the hitch at all.

There are lots of us engineers who understand that to take advantage of weight distribution equipment, to distribute the effects of the tongue weight to other than just the rear axle of the tow vehicle, a receiver is required that is sufficiently strong to handle the forces. A hitch not designed for WD use may not be strong enough. Adding a brace to that hitch to spread the loads out is not rocket science. There are documented best practices. And lots of prior examples to check out.

With domestic heavy pickup trucks, notable RAM and GM, there were years of examples of hitch receivers not being strong enough. The solution was to install an aftermarket receiver (Curt, Drawtite, etc) that was built stronger. Not rocket science. And exactly analogous to strengthening a receiver on an Audi or an X5.

I don't see the relevance of the Vespa point; it is similar to regular references to towing an Airstream with a bicycle.

I don't understand the relevance of crash testing to vehicle tow ratings.

[Shiny16]

Originally Posted by jcl

I am also a mechanical engineer.

The SAE standard is voluntary. They don't have to follow it at all. And you confuse the issue by adding the word safety in.

It is not a performance standard. It is a test standard. It specifies a set of standard conditions so that manufacturers can test their vehicles under those common standards, and thus consumers can compare ratings from one manufacturer with the ratings of another manufacturer. It is a comparison shopping tool. Where it can become influential on safety is when some US manufacturers, who were in a type of arms race to constantly increase their tow ratings, had to rein it in a little. This applies most to product classes such as pickup trucks, where higher tow ratings are seen as a marketing feature.

For Euro SUVs, the most common benchmark tow rating is the break point where users would require different (more stringent, more expensive) licensing for their tow vehicle and trailer. It is a metric figure, but translates to 7700 lbs. For a Euro manufacturer to rate to that figure (and they nearly all do) they test to that figure. End of story. They don't test at a higher trailer weight, and don't claim that the figure is the ultimate capability of the tow vehicle, they see no reason to go higher. They simply use a convenient figure that consumers look to.

If we wanted to use the SAE tow rating test standard to determine what is safe, we would have to go a lot further than the SAE test standard currently does. For example, we would consider wind loading and sway. We would use test trailers that more closely approximate travel trailers. We could test the trailer brakes, eg we would actually connect them, and we would test the tow vehicle brakes at more than 20 mph on a flat road. We wouldn't make the hardest braking test to overcome the parking brake test. Those factors could provide some guidance for those who want to rely on the SAE standard as an indicator of what is safe or not. Until then, it is convenient in that we can say that a Ford was tested under the same conditions as a RAM or a GM. But don't assume that those are real world conditions, that would be very dangerous and would lead to the unfortunate situation whereby people purchased tow vehicles primarily by their tow ratings, and subsequently paid less attention to the importance of towing setup, since "it is rated for that".

Ok so I’m not an engineer. I really believe that in the worst case If one of these creative tow solutions were to end up in a court that the jury would be more apt to take the word of Audi engineers over what a guy from Canada said on a public RV forum.

[jcl]

Originally Posted by Shiny16

Ok so I’m not an engineer. I really believe that in the worst case If one of these creative tow solutions were to end up in a court that the jury would be more apt to take the word of Audi engineers over what a guy from Canada said on a public RV forum.

You can call it the land of the free, if you like Free to develop and use the best combination towing solutions, free from overzealous litigators, and so on.

Where do we find Audi engineers trained in best practices related to the use of WD equipment? First question: Tell us about your experience setting up Airstream trailers with your products, using WD equipment? No? Let's introduce a different expert witness then (not me). You think the Audi engineer is the last word?

[JonDNC]

This is getting silly

There are two maybe three camps that will never agree

1). I can tow anything I want if I believe it can work. Especially with a German SUV

2). Stay within the numbers, as long as you’re under the number all is good and a few hundred pounds may or may not matter.

3). Be conservative, if you don’t have 20% extra headroom, your probably too close to the edge in the exact wrong situation.

Every tow vehicle thread ends up at the same place that I’ve seen in the last year. No matter what your experience has been someone somewhere will tell you wrong.

[qwertyd10n]

Hi Jamies,

First of all congrats on the new trailer and tow vehicle combo - they're both quite impressive!

Second, I can only give you my limited experience with a similar combo so far in our early days of owning "Olive" - a 2019 International Signature 27FB. We pull Olive with a 2009 Porsche Cayenne Turbo S - 550hp/553 ft lbs of torque, along with air suspension but no "tow mode" like yours has.

Olive came with a Fastway E2 10000lb weight distributing hitch which I set up immediately after the purchase with air suspension off as per the directions. Andy and Philip at Can Am have suggested the Eaz-Lift WDH, which I might consider in the future, but the E2 is what I had for the tow home and it worked great.

The trip home was approximately 600 miles through the Canadian Rockies and the Cayenne towed Olive like a champ. No sway on two way roads when passing larger semis or buses, no porpoising - just solid and steady right behind the Cayenne as you'd want and expect it to be.

Others have already and likely will again tell you that your shorter wheelbase tow vehicle is inadequate, but from that trip home and one other camping long weekend since I'm pretty convinced of the capabilities of a vehicle similar to yours. I'd also place a small wager that I could out brake a 3/4 or 1 ton truck pulling the same trailer... our 380mm front rotors provide unreal braking - as long as the trailer brakes and controller are setup properly of course.

One question I do have is why your tongue weight is so much higher in the 27 GT vs our 27 International? I checked ours with a Sherline scale with full propane tanks, batteries, and partial load (no fresh water) and I was just under 840lbs per my picture.

Cheers,
Dion

[jcl]

Originally Posted by JonDNC

This is getting silly

There are two maybe three camps that will never agree

1). I can tow anything I want if I believe it can work. Especially with a German SUV

2). Stay within the numbers, as long as you’re under the number all is good and a few hundred pounds may or may not matter.

3). Be conservative, if you don’t have 20% extra headroom, your probably too close to the edge in the exact wrong situation.

Every tow vehicle thread ends up at the same place that I’ve seen in the last year. No matter what your experience has been someone somewhere will tell you wrong.

It has been silly for some time.

For a real kick, read some of the tow threads from the 2009/2010 era. Especially those involving German SUVs and Japanese minivans.

My favourite bumper sticker from that time was "You can't tow with that!"

And the usual response was "Cue the busload of orphans...."

[GCinSC2]

Originally Posted by jcl

.
My favourite bumper sticker from that time was "You can't tow with that!"

...."

And from the fine folks at the Turbo Diesel Register a forum for the Dodge Cummins folks www.tdr1.com one of their OLD stickers was.

Load the wagon, don’t worry about the mule.

Just meaningless fluff.

[Shiny16]

[QUOTE=jcl;2424453]You can call it the land of the free, if you like Free to develop and use the best combination towing solutions, free from overzealous litigators, and so on.

Where do we find Audi engineers trained in best practices related to the use of WD equipment? First question: Tell us about your experience setting up Airstream trailers with your products, using WD equipment? No? Let's introduce a different expert witness then (not me). You think the Audi engineer is the last word?


I’m not quite sure what your talking about. This country is certainly not free from over zealous regulation.

Substitute Audi engineer with Ford Chevy ect. You know the ones with degrees in this field. What certifications does CanAm have? Does CanAm offer any new certifications for the vehicles they retrofit? I’m sure many things can be done well by outfits like CanAm but again who do you think a jury will believe? I would rather not have to find out. Sticking with the guidelines that the car manufacturer publishes limits that chance.

[Seanlb]

Originally Posted by Shiny16

Ok so I’m not an engineer. I really believe that in the worst case If one of these creative tow solutions were to end up in a court that the jury would be more apt to take the word of Audi engineers over what a guy from Canada said on a public RV forum.

Someone finally said it

[mythbuster88]

"Hello! Very excited to be posting here as new owners of a 27' Globetrotter. We also have a beloved, new Audi RS Q8. We're thrilled to participate in Air Forums, finally!"

This is the problem here:

The OP loves the car and one of the first rules of camping is you can't take all your belongings. Choose wisely.

[waninae39]

EURo engineers don't and can't test WD on their vehicles at WD is not allowed in EURO

in the 60's the laws changed and disallowed vehicles to pull anything more than a very light load. The new hitches were designed to FAIL if heavy loads were pulled.
That is way you don't see any big trailers in EURU/UK

[jcl]

Originally Posted by waninae39

EURo engineers don't and can't test WD on their vehicles at WD is not allowed in EURO

in the 60's the laws changed and disallowed vehicles to pull anything more than a very light load. The new hitches were designed to FAIL if heavy loads were pulled.
That is way you don't see any big trailers in EURU/UK

I lived and worked in the UK for three years, and travelled through France, Italy, Germany, and Spain. I saw lots of big trailers. We also used relatively heavy trailers (not travel trailers) at my work, with a fleet of company trucks, ranging from Land Rovers to Transits.

[Etrax]

2 1/2 years ago we bought a GT 27 and planned to tow it with our Cayenne S. We towed with it three times And it really towed well. However, I was never completely comfortable with the risks that many have brought up such as liability etc. and we canceled our trip to Can-Am to have the hitch reinforced and instead purchased a Ford F150.

Honestly the Porsche probably towed a little better as it was stiffer and the steering was tighter but there’s no substitute for having a pickup for hauling, especially since the GT doesn’t have much storage. . I use a blue ox WDH and I’m not overly impressed with it and I’m confident I have it set up correctly.

Now I’m considering upgrading to a three-quarter ton or upgrading my WD hitch to potentially a Hensley. There’s been too many times driving on windy highway where the trailer steers me towards a passing semi. I don’t like that!

Good luck - ultimately it’s your decision. Welcome to the Airstream family!