Thx for the add, I’m sure I’ll get better answers from you guys then Mercedes.
I’ll keep it simple,
A: What travel traveler weight should I stay under?
B: can a GLS 450 be configured to tow if it did not originally come with a tow package?
C: what brand is favorable and affordable in 2018-2021 Travel Trailers?
D: what brand or year should I avoid?
E: MB offers the parts on their website but claim that “they” don’t offer towing package unless it’s ordered that way...

So update:
2019 MB Gls 450 is advertised to tow
Has towing instructions in the manual
Has part numbers for the tow package parts
But can NOT be retrofitted to tow if it did not get preassembled at the factory....
I’m in contact with someone from USA MB to find out why, he said he was not aware this was a thing and is venturing to find out.
This is some ****ty **** they did








If ya could help out in any way I’d be much appreciative.

 

Answer to E:
First, all Mercedes GLS/GLE have the HD engine and tranny cooling, an HD alternator that many vehicles need as options to prepare them for towing.

However, the W/X164 and 166 (prior models) had significant internal chassis strengthening as part of the tow package. Tow package was a $750 option if factory installed, and it also included a different rear SAM (Signal Acquisition Module) that senses the presence of a trailer, affects transmission modes, allowed Trailer Sway Control, and gives trailer "bulb out" warnings in the instrument cluster. All of those things, when installed later, cost about $25-2700 because of the labor involved. A lot is dismantled, parts replaced and reassembled.
I think you have posted all or most of the parts needed to do a factory retrofit, except the chassis reinforcement. I'd hate to order those parts and find that a key part was missing or unobtainable. As you see, the rear crossmember is needed.

I don't know if the internal chassis reinforcement is part of the V/X167. I have not been able to find a blow-up of the new GLS to see the hitch mounting and parts, so I am making a somewhat educated guess with this reply.
I was surprised to find that M-B didn't offer a hitch package through parts, but since there are so many parts, I think I understand. Plus I found out that not all Dealers were knowledgeable about installation and flashing of the SAM on the previous models.

Having said all this, I would not install a U-Haul hitch, or a Husky or other hitch. eTrailer.com shows a few, and although eTrailer is a usually trustworthy source, I don't agree that their kits are safe.

Then there's the wiring. As I mentioned, the factory tow package shows bulbs out and interacts with the transmission/engine mapping, and trailer sway control. Just tapping into a brake wire, as on the U-Haul or eTrailer sites, won't give those functions. And it might have an adverse effect on other car functions - I don't know about that. AND there was internal wiring for a Brake Controller to plug in under the dash.

Short answer - if you want to tow a trailer, look for an M-B with the tow package factory installed. If all you want to do is carry some bikes on a hitch mount, that might be OK.
Good luck!

edit: If you are talking about a 2019 GLS, it's a X166, all the above applies directly, and there ARE internal reinforcements. Here's a picture of all the parts that come in the factory kit. It should still be available for a 166. Note the bars in the foreground - they are inserted into the chassis - the reinforcements I mentioned above.


See the bars in front - they are inserted into the chassis

 

@Edward Polanco You are asking about the 2019 GLS 450, correct? That is the X166 platform. This is the X167 section of the site.

MB dealers are generally useless on the topic of towing, among many other topics.

A. Total towed weight must not exceed 7,500 lbs. Towed weight = trailer + propane + televisions + bedding + dishes + etc + etc

If you choose to tow near the maximum weight of 7,500 lbs, it's best to use a weight distributing hitch and an electric brake controller. The RV dealer can instruct you about this.

 

RV Dealers are similarly uninformed about towing, unfortunately, unless you are lucky. Good that you asked a forum.
You might also join an RV forum to get their input. The Airstream forum is a good one, as is the Lance forum. I learned a lot from them (I pull a Lance.)
And I'd recommend a WDH and brakes for anything over 3,000#.

 

@Edward Polanco I edited my post above (#2) to show the actual hitch components for your X166.

Regarding max trailer, your Payload will be the limiting factor in how much you can tow. While the clip you showed says "max total payload 1765 est," every option that's added decreases your payload by that amount. Look at the sticker on the Driver's Door Post and you will likely see a number between 1,100 and 1,350 as a payload. Payload is everything over a 150# driver and a tank of gas.

The reason payload is the limiting factor, is that you want 10 to 15% (my target is 12%) of the total trailer weight on the tongue, to resist sway. Less than 10% and you WILL likely have sway.
So if you tow the max specified weight, 7500#, you will need at least 750# on the tongue and you have no payload left over for a copilot, dog or lunch. Plus I think the hitch is rated (label on it, too) at @650#.
So you have to work backwards from the payload. Figure how much weight (passengers etc.) you expect to carry, then subtract that from the payload, to figure how much tongue weight you can carry. THEN divide that by .10 to see how heavy your LOADED trailer can be. (DO NOT go by advertised "Dry Weight." As with the M-B (or any tow vehicle) payload, every option on the trailer will add to the Dry Weight. In my experience, most people end up at the trailer's GROSS WEIGHT - if not over - after putting in bedding, dishes, a tank of water and groceries.) In my case, my Lance dry weight was 4414# but, loaded for a week on the road it was RIGHT AT the trailer GVW of 6,000#. Just figure the Gross weight of your trailer.

I cheat and go by separate F & R Gross axle weights, which are also posted in the door post. It involves a trip to the scales to weigh your axle weights, after you have adjusted your WDH (Weight Distribution Hitch). I don't recommend you do this, but I do and I'm incredibly stable. I have a few hundred pounds each axle to spare.

 

As others have said, your best bet it to find a GLS with the tow package from the factory. There are 3 main towing parameters: 1) What you can pull depends on the tow rating (7500#), 2) What you can haul depends on your payload (GVWR - curb weight), and 3) What trailer tongue weight you can handle depends on your receiver rating (600#). In general you run out payload (includes occupants, cargo, trailer tongue weight) way before you hit the tow rating limit. My suggestion is to keep the loaded trailer weight under 6000# to have some reserve capacity, for a more relaxed towing experience. I've heard good things about BigFoot trailers. An RV forum would be a good place to research that.

 

P.S. You can find your vehicle's payload by looking at the yellow sticker on the driver side door jam. For GLS is usually between 1100# to 1300#.

 

they are nice but a bit expensive
please point me to the correct forum
it seems I can’t locate the GLS 450 or maybe there is none

 

i like our Lance, lightweight but they've gotten expensive.
For RV's, think about how you will use it. Back roads, off-grid, strictly pavement etc.
Some, like our Lance, have low slung Dexter axles and handle well / avoid big winds.
Others have big ground clearance and big tanks for rougher country.
Good luck.
There may also be a glut of recent purchases from COVID, when buyers' remorse sets in.
Try this link or go to the X166 forum under SUVs. https://mbworld.org/forums/gl-class-x166-173/

 

Sorry, I don't know the best forum for BigFoot trailers . Have heard good things about them in other RV forums (Apparently they are well insulated and a 4 season trailer). Another trailer which seems to have a good reputation is Oliver. They have a fiberglass shell. I own a vintage Avion trailer and can answer any question about them (In case you are into vintage trailers).