Towing with used Audi Q7 or Mercedes ML350

[Small but Sweet]

We spent the afternoon at a used car dealer who had one of each of some of these cars. All I can say is, never look at a Mercedes FIRST. It's definitely my favorite now mainly because of the small size with a large tow capacity (7,700?). Also the ride felt like we were floating, it was so comfy.

One concern though - the sticker in the door listed cargo+passenger load max 992 lbs. Our expected tongue weight and us two bodies would only leave 150 lbs for tools, firewood, and the rest of the clobber we bring. This doesn't match up with what I'd read as specs for the ML350 so I need to do more research. I guess we could shift more of the load into the trailer though. Is there some weird magic math where they don't mean tongue weight in that max?

[Civilguy]

Is there some weird magic math where they don't mean tongue weight in that max?

There is no magic, which only leaves us with the equally unhelpful wishful-thinking. Tongue weight gets deducted from rated payload capacity. Period.

Our pre-owned 2010 Q5 was a wonderful tow vehicle for our tongue-heavy Casita 17. It had a factory wiring connector behind the dash on the left and I installed a Tekonsha P3 brake controller. I cobbled together the parts for the controller's end of the wiring connector as per an Audi forum post, obtaining them from a VW dealer.

I kept the brake controller and installed it in our new tow vehicle when I sold the Audi.

I had the Audi dealership install the factory hitch assembly. They were not experienced, and it took the tech some time, but he got it done. It wasn't inexpensive, but I didn't want to mess about for the sake of trying to save a couple hundred dollars.

I was going to go with the Q7 for our Escape 21, but one of the points I really disliked was the lack of a full-service spare tire. In the end we went with the JGC and have been content with that.

[Janet H]

I used to have a 2008 Touareg and now tow with a 2020 GLE 350. In both cases they came with hitch already installed and in both cases the brake controller issue was substantial. In the Touareg I had the wiring added and a standard brake controller (costly). With the GLE 350 I solved the brake controller issue with the Tekonsha RF system. It's fine and a much cheaper route than a total rewire. On both I have a hitch with Weight distribution and sway control

If you are considering any of these take a hard look at the GVWR on the car as well as allowable weight on the rear end. These SUVS often don't have a lot of headroom for additional weight. Will you have passengers, extra gear in the rig, boats on the roof? It all adds up.

I generally travel solo and both rigs have been fine. That said, I preferred the Touareg for a few reasons. (Stiffer ride, Higher GVWR, Fewer electronics..)

In the VW and Mercedes line (not sure about Audi) the "towing package" was a dealer option but neither included the prewire for a brake controller. Instead, the "tow package" was the factory installed hitch.

[Small but Sweet]

Thanks Janet, that’s a lot of the things I’ve been thinking about too. We would want to hardwire our brake controller because we really like the one we had before. John isn’t afraid of doing that work but others have pointed out that it can quickly escalate to a more tricky job. There’s a Mercedes ML350 near us that we’re thinking about but once we are inside and the tongue weight is on, it only leaves about 250lb for other cargo. I have been thinking “well, we can put things in the trailer instead of the car”, but really that’s a small margin. That car nearby already has the hitch and the 7-pin in place. The attraction is that I love the comfort of the Mercedes, but then we wonder if an ordinary Tahoe or something would just be less fiddly.

[Janet H]

Originally Posted by Small but Sweet

Thanks Janet, that’s a lot of the things I’ve been thinking about too. We would want to hardwire our brake controller because we really like the one we had before. John isn’t afraid of doing that work but others have pointed out that it can quickly escalate to a more tricky job.

I had this concern as well. and was not even a little comfortable with the RF brake controller. Turns out it's fine and has the same controls a hard wired brake controller does - there's the same manual control. You can mount it on your dash or console with some removable velcro and then pull it down when not towing.

There are two other benefits:

1. You can move it to another vehicle that has a receiver very easily.
2. No need to mess with the cars computer. This can be a big headache... for the Touareg I had to buy the system software, interface and dongle to reprogram the computer AND learn how to do it. It had to be redone every time the battery in the car was disconnected as the computer would default back to factory specs.

All that said, I understand the desire to tow with a daily driver. Balancing act...

You've probably read this? https://www.motortrend.com/features/...w-7500-pounds/

[Small but Sweet]

Thanks Janet. Of the many articles I’ve been reading about SUVs, that's a new one for me.

P.S. wow I had never heard of a Bentley SUV! Way out of our budget of course. There is currently a used Range Rover in our area for sale - I told John that William and Kate (Duke and Duchess of Cambridge) drive one of those, LOL. It seems most of these exotic ones have some very specific quirks with compatibility and readiness to tow, or difficulty getting parts but I would love to ride in comfort like that.

Our pickup date for the 21C has moved to February. We know we can at least go fetch it from Sumas with the Highlander. If we seem to do OK with the Highlander we'd be only too glad to keep using it.

P.P.S. I’d be happy in any of those towing SUVs in the article.

[Donna D.]

Originally Posted by Small but Sweet

Our pickup date for the 21C has moved to February. We know we can at least go fetch it from Sumas with the Highlander. If we seem to do OK with the Highlander we'd be only too glad to keep using it.

Yeah, but Harriet there are NO mountain ranges between you and Sumas. But once you get home and want to go west, there's the Coast Range to go over and east there's the Cascades. Those may make big differences in towing with your Highlander.

[skyfree]

Originally Posted by Janet H

2. No need to mess with the cars computer. This can be a big headache... for the Touareg I had to buy the system software, interface and dongle to reprogram the computer AND learn how to do it. It had to be redone every time the battery in the car was disconnected as the computer would default back to factory specs.

I'm curious about this. I had a 2011 Touareg and it was completely plug-and-play to add a brake controller. No need to reprogram anything. It's the same platform as the Q7/SQ7 and just like the SQ7 all I had to do was to find the socket and plug into it. The battery was disconnected once or twice and I never had to do anything special after.

[David H]

I have a 2016 Touareg TDI and it was the same, plug and play once connected to the already in place plug located upper left under the dashboard. Bought the factory pigtail from the VW dealer to splice to my Voguer brake controller. All leads on the pigtail were correctly marked and it was an easy mating to the controller harness. Worked perfectly first time.

[Janet H]

Originally Posted by skyfree

I'm curious about this. I had a 2011 Touareg and it was completely plug-and-play to add a brake controller. No need to reprogram anything. It's the same platform as the Q7/SQ7 and just like the SQ7 all I had to do was to find the socket and plug into it. The battery was disconnected once or twice and I never had to do anything special after.

Maybe a year difference? Mine was a 2008 and I grudgingly parted with it last year. The Brake controller was dealer installed but the computer settings were a chronic problem.. If you read the Touareg forums you can see this issue over and over for these early years.

It was a better tug than the Mercedes I replaced it with. I looked hard at the Audi which is probably a better vehicle but the deal breaker for me was the 3rd row seating which was a standard item and stole cargo space from the rear. I need that space and rarely have any passengers.

Since this is my daily driver towing wasn't the only consideration. I am a touring musician and often have a lot of bulky gear in my car. Losing valuable space to unwanted seating was a no brainer.

Hoping this new ride will survive the 12 years and 200 K miles the VW did but think it may not be as robust.

[BobG]

The Audi comes prewired for a brake controller to plug into. I don't know if it comes that way if you don't buy the tow package but I think it does because the rear end comes wired for the tow hitch assembly to plug into. You buy a brake controller that you want and a pigtail connector to fit the brake controller on one end and the Audi plug on the other end. Mount the brake controller and plug it into the plug that is located behind the dash. For me it was an easy operation other than I didn't buy the ready made pigtail. I made my own and got it backwards first try. I was in a real hurry when I did it.

[Small but Sweet]

The ML350 that I ~really like~ has a payload of only 1170lbs. Minus 550 tongue weight (if it’s heavily loaded) and minus our combined personal weight, leaves only 260lbs of tools, firewood, baggage, and we couldn’t bring any passengers. So it probably won’t be the one for us.

Also I am very struck by John’s excellent point - paraphrased - a cheap Mercedes can be very expensive.

Originally Posted by Civilguy

There is no magic, which only leaves us with the equally unhelpful wishful-thinking. Tongue weight gets deducted from rated payload capacity. Period.

Our pre-owned 2010 Q5 was a wonderful tow vehicle for our tongue-heavy Casita 17. It had a factory wiring connector behind the dash on the left and I installed a Tekonsha P3 brake controller. I cobbled together the parts for the controller's end of the wiring connector as per an Audi forum post, obtaining them from a VW dealer.

I kept the brake controller and installed it in our new tow vehicle when I sold the Audi.

I had the Audi dealership install the factory hitch assembly. They were not experienced, and it took the tech some time, but he got it done. It wasn't inexpensive, but I didn't want to mess about for the sake of trying to save a couple hundred dollars.

I was going to go with the Q7 for our Escape 21, but one of the points I really disliked was the lack of a full-service spare tire. In the end we went with the JGC and have been content with that.

[Small but Sweet]

Our heads are spinning from all the car choices. I think we will perhaps just drop the search at this time until we know more about what we want - what’s our main criterion. Torn between ecology guilt and wanting to be confident about the capabilities.

[Civilguy]

Torn between ecology guilt and wanting to be confident about the capabilities.

Towing does that. Growing up after Rachel Carson had published Silent Spring, I ran air-cooled VW's and various little foreign cars for decades. I had to give up a beloved Passat when we got a Casita.

Then I end up with a V-8, right when we're supposed to be saving the planet; do I get credit for time served in the 4-cylinder class?!?

As far as the tongue weight goes, 550 is a good number to keep in your sights. Our 21 was delivered at 525 lbs. over the published 3,735 lb. dry weight due to options like AC, dual 6V batteries, etc. I've measured the loaded tongue weight at 460 to 540.

Nobody ever had their trailer start to push the tow vehicle around and said they were glad they had cut it close on rated capacities. Ours is an adequate tow vehicle with 720/7,200 lb. tow ratings, but there are times I wouldn't mind if it was even a bit more "adequate".

[Small but Sweet]

Yeah - I'm getting shamed from my parents about needing a bigger vehicle! We immigrated from Europe long ago and they take a dim view of the North American comfort level with taking more than our share of everything. But then, my parents have always taken transatlantic flights sometimes more than once a year, and our "camper towing" all year long is less damaging than a long-haul flight - right?!

[Small but Sweet]

Originally Posted by Civilguy

Nobody ever had their trailer start to push the tow vehicle around and said they were glad they had cut it close on rated capacities. Ours is an adequate tow vehicle with 720/7,200 lb. tow ratings, but there are times I wouldn't mind if it was even a bit more "adequate".

Hmm, that’s good input. Makes me think that 720/7,200 should be the starting point, ideally.

[Civilguy]

Originally Posted by Small but Sweet

Hmm, that’s good input. Makes me think that 720/7,200 should be the starting point, ideally.

Our Grand Cherokee pairs a 5.7 V8 with an 8-speed transmission, providing higher tow ratings than V6 models. It does fine pulling grades, etc. Incidentally, the fourth-generation WK2 JGC is a product of the Daimler-Chrysler era and shares the same platform as the ML350.

Our JGC is an Overland trim with over-sized brakes and a Quadra-Trac II Hi/Lo range 4WD system that's guaranteed to surmount any parking-lot curb-stop in the Western Hemisphere.

My comment about the JGC being "adequate" partly relates to how it compares to the Q5 (440/4,400 lb. capacities) towing the Casita 17; that was a superb combination, and we always towed without a WDH.

The Jeep manual recommends that we use a WDH when towing at or above 5,000 lbs. of trailer weight. We pull about 4,500 lbs. without one, but I keep thinking I should give a WDH a try.

For those interested, I've posted several times about the Grand Cherokee on the FiberglassRV forum:

https://www.fiberglassrv.com/forums/...tml#post772389

[dan55]

I tow with a 2019 GLE 400 same size as the GLE 350 different engine. Ours had the hitch and 7 pin plug. There is a plug under the dash that you can connect a brake controller to. I made my adapter cable and use a Tekonsha P3 controller. You need to be care where you mount the controller as there is a airbag for the legs, works great tows our 19’ with no issues.