I see a ton of information on weight and towing trailers and seems I’m good on weight. All of our “truck” friends insist we will cause major issues to the air suspension if we use the Mercedes to tow a 2 horse trailer. Any concerns with suspension?What about dirt roads?

I don't have experience towing a horse trailer, please use weights in lbs or kg as I don't have any intuitive idea of the weight of a loaded two-horse trailer. I've towed my 6500+lb (loaded) travel trailer for thousands of miles with no air suspension issues, but I've adjusted it to keep the tongue weight at a manageable level to reduce stress on the air suspension. And I don't load up the GL with many people or much cargo so the rear axle isn't overloaded. I also use a weight-distribution hitch, but I don't know if those are used for horse trailers? Towing on dirt roads may create higher dynamic loads, large bumps at speed could create spikes in the tongue weight. But I'm sure you're driving carefully since you're pulling live animals. I've found that usually Mr. You-Need-A-Dually-3500-Diesel-To-Tow-Anything-Other-Than-A-Utility-Trailer doesn't understand how capable the GL is for towing, and that the billions of people living in other countries around the world have figured out how to move things without a Ford Superduty King Ranch.

Tow up to the vehicle’s GCWR.

Typically MB SUVs have a 7k lb tow rating, maybe 7.7k lbs. Read the door decal and owners’ manual. Owners’ manuals are available online at mbusa.com

If the vehicle has a factory hitch receiver, tow with confidence up to the rated capacity. Doesn’t matter if horses, bricks or pillows are in the trailer.

7000lbs of pillows is a pretty long or tall trailer!😂

Assuming a 2 lb pillow, subtracting the 3500 lb enclosed trailer weight from the GL's towing capacity, and assuming the pillows aren't individually boxed and would crush the bottom layers pretty flat, I calculated that you could squeeze about 2000 pillows (4000lbs) into a 25 foot trailer. It actually wouldn't be that bad to tow with the GL, lol.

MB SUVs are superior tow and off-road platforms.

Some, not many, people realize the towing capability of these vehicles.

Almost no one realizes the off road capability these machines can deliver. 4MATIC + 4ETS give nearly Jeep- and G-Wagen level performance without paying for the MB off road engineering package or G-Wagen price, while enjoying the comfort of an independent suspension MB vs a solid axle Wrangler or G.

The main limitation of these vehicles off road is low profile highway tires and large diameter wheels. Very easy to rash the wheels and the tires aren’t the best in some situations. Smaller wheels and more rubber creates an awesome MB off roader.

I called my service rep and he confirmed 7500lbs/750lb tongue weight. Someday, perhaps my money pit will come out of the shop and I can use it. Does anyone know of the connection is a “7-Round” on the premium tow package? I’d look - but the car has been in the shop almost the entire time I’ve had it.

Should be a round 7 point electrical connector by the trailer hitch. A trailer brake can easily be installed using the connector that can be found under the driver's side dash: Look for a green 4 pin connector that's likely stashed behind the insulation under the pedals.

7 pin round is the factory receptacle on the vehicle.