drjonez

Just completed a 1500 mile towing trip with my 2011 TDI. Part of my motivation in buying a Q7 TDI was for towing, though I'm no towing veteran so perhaps my expectations were not properly tempered. I was unable to find a Q7 with air suspension, so I'm stuck on steel suspension and <gasp> ended up using a Eaz Lift WD hitch after reading up on what the Touareg guys do and what CanAm (Airstream fitters in Canada) do/recommend. We can debate the use of a WD hitch in a different thread (though it seems to have been done...) and no, I haven't reinforced my hitch yet either. I did install the friction sway control that came with the hitch, but did not use it.

The Q7 was loaded with 2 adults and 4 kids, we were towing a 2006 R-Vision Maxlite 23RS, 23' travel trailer rated at 4000 lbs and 425 lbs hitch dry. Here's how it weighed out loaded:



Overall, the Q7 towed well. Reasonable driving around town. As some have mentioned in other threads, you need to "train" the trans control that it is towing by shifting manually for a while. Once that is done, it won't seek high revs or shift as frequently. No sway issues to speak of. I've read some things that say that once a trailer is detected, the Q7's stability control works to mitigate sway...I can't really comment other than to say towing was uneventful, even in heavy crosswinds. Anything more than 70 MPH on the freeway and the trans would hunt gears if there was any change in terrain; fuel economy suffers substantially as well. 65 MPH seems to be the sweet spot. Here's how fuel economy shook out:
Total average: 10.67 MPG
72 MPH average speed: 9.8 MPG
62 MPH average speed: 12.2 MPG

One shocking aspect was DEF consumption: it consumed near 5 gallons of DEF over the course of the trip. Worse yet, its ability to calculate DEF capacity and consumption was a mess. It appears my Q7 has the old software on it- once the "countdown" to no start was triggered on the dash, no amount of adding DEF cleared it. Had to stop at a VW dealer and found a tech with VCDS to sort it out (since I foolishly didn't bring my laptop/VCDS). After that episode, I ended up adding DEF at each fuel stop.

How does this compare to anyone towing similar payloads pre-fix?

Only pic I had of the whole rig loaded, perspective makes it look sort of weird...

dreadlocks

I get much better FE, I'm pretty close to you weight wise but I got a gen2 TDI w/more power, does 2001 have 8spd?.. I get about 12-14mpg at 65-70mph.. my best towing at mostly 45mph through mountains was 17mpg.. your numbers are more what I'd expect out of mine trying to do 80-85mph.

Def countdown is not based on current fuel economy, just whatever they decided was normal.. I went from a 1200 mile warning to a 600 mile warning in less than 300 miles, luckily mine resets correctly when refilled.. I use very little DEF, I can refill and go 1500 miles without it ever coming on towing.

drjonez

Good data. IIRC you haven't had the fix yet? gen2 does get a touch better FE. Yup, the 2011 does have the 8 speed. I'm jealous of your DEF use/functionality...

J. Patterson

FWIW our pre-fix 2011 would always reset the DEF warning when I added DEF after it came on. It would not reset immediately though. Did so after a few start shutdown cycles and several miles driven.
So far on the 2015 ( fixed) that replaced it, I’ve never had the light come on. I’ve added about 5 gal at each of the services I’ve done. ( 3 over 25000 miles)

Greg5OH

Can you post a couple pics of the WD setup?
Did you try it without a WD setup to see about the sag?

I have been considering retrofitting our Q7 with the factory AAS to get the load leveling. Or at minimum replace the rear coils with OEM air struts, source an OEM compressor and tank, and have a manual setup..

I saw the Q5 post on how it was reinforced. To do the job of bracing its fine..but good luck removing the muffler or servicing anything else under there, they just weld it straight to the upper rear axle bulkhead area! I would must rather a bolt in design. Weld a plate at the receiver end with a bolt in double shear, and a plate welded to the bulkhead, with 2 holes drilled for a clamping load to be applied.

drjonez

No good pix of the WD setup directly, it's this one: https://www.eaz-lift.com/product-pag...lite-hitch-kit I got the 1000 lbs version because it was the cheapest. No difference in versions except the torsion bars.

Here's worst case sag with a full cargo load in the Q7 (i.e. whatever shank I had sitting around to drag the trailer home, it could be improved if picked the correct shank height):


Sounds like we need to talk or at least coordinate efforts, this is on my list of things to do. Current state of my research: lots of chatter about the dangers of having air springs at only one end. As far as I can tell, OEM air springs only fit on the OEM air struts....which have adjustable damping...and cost a ton.

Once again, we're on the same track. The stuff that CanAm does looks a bit sketchy. If I continue to tow and use the WD hitch, I will end up doing exactly what you describe- make it a bolt in affair affixed to something more structural.

Greg5OH

That pic of the sag: looks like thats jsut regular hitch with no WD correct? If so that looks completely fine and normal

Regarding air springs at one end-no harm with it. BMW X5s have been coming like that from the factory for ages.
My thought was just to unbolt the stock rear coilovers, and bolt in the stock air or damper assembly. As for the adjustable damping...other than OEM controller havent figured a good solution yet. Im assuming it changes damping with different height settings.

Basically, the way i retrofitted the factory towing setup. use OEM harness, module, plug etc. The Chassis is wired/room is there for compressor/tank etc..just plug and play.

Since the Q7 allows 660 on the tongue, assuming the 400 on the tongue is the sag picture you posted-it all looks fine to me. Id rather not use a WD myself, simply cause I dont want the hassle of dealing with the hook and unhook of it, as we would probably by unhooking the camper everynight to leave at "base camp"

drjonez

Correct- no WD and the wrong height shank. I agree, totally normal.

Agreed on the air springs at one end- just more fearmongering from lack of knowledge.

Damping adjusts based on your setting.

I was hoping to just bolt on the air springs....but seems doubtful at this point.

Dropping the WD at camp each night wasn't that bad at all...perhaps an extra 7 min or so.

Greg5OH

You could just bolt on the air springs. I woulnd tdo it this way-in case there is a leak, but you COULD, install both air springs (entire spring and damper body) run two line sot the back hitch area to a 2 schrader valves, pump up each corner to desired psi.
Then can get fancier with compressor/tank and manual switch, and then go full fancy and do 4 corners with module, compressor coding etc.

drjonez

My plan was some sort of aftermarket controller....or perhaps I'll just be lazy and run one line and schrader. Keep me posted on your progress.

I assume you've seen the retrofit thread on clubtouareg?