I bought my 2012 GL550 about 3 years ago with 110k on it for the primary purpose of towing our boat while carrying the family to the lake. It has been great in all regards. We previously towed with an Audi Q7 with 4.2L V8 6 speed AT and 2012 Nissan Xterra PROX-4 5 Speed AT. The Audi did a fine job, but my wife was not a fan of it and wouldn't drive it. It had enough power and would hold gears fine, but you would get a few inch sag in the rear with boat, passengers, and gear in tow. The Xterra was great with its short wheelbase for backing up in tight spots and was fine with driver and passenger pulling the boat, but you could really tell adding 2 or 3 passengers pushed it to items limits and was taxing it considerably.

With my GL550 recently needing a fuel pump, my father-in-law offered his 2016 GMC Seirra 1500 double cab 5.3L with 8-speed Auto. I was very curious to see what it would do since it was built for this type of duty. Hooking up the boat was easy as it had multi-pin options and it had no problem with tongue weight. Parked on the street in looked the part. Driving around the neighborhood it felt fine and capable. Once on the road, I started noticing how much more you could feel the boat behind you. The 5.3L certainly was down on power. The braking was subpar, but I noticed that even empty there was just no bite. All in all it reminded me of pulling with my old Audi Q7. I am sure a 6.2L model would help with power, but don't think the braking or suspension would be helped much.

The air suspension in the GL550 really does a great job of eliminating those random tugs you feel as you pull. The 5.5L delivers plenty of power and the air suspension really works wonders for towing. After all of this, I really question the crowd that says the Tahoe/Yukon/Suburban is the way to go for family tow rig. Maybe it would be different if I was pulling something bigger than my Yamaha 212x which is 21 feet long and 5000+lbs with boat/trailer/gas/gear.

 

Those crowds seem to think unibodies will fall apart with any bit of load. That said, the Suburban/Expedition Max are in a size class of their own for SUVs, so they have that advantage. Also, it is a bit of an unfair comparison as the GM 5.3 is the base engine and the 6.2 is more comparable to the Mercedes 5.5. Also the GM 8 speed is known to be a terrible transmission.

But yes, I fully agree the large German SUVs are far superior to their American counterparts for towing.

 

The GL550 does look tiny in front of the boat, but braking, handling, and stopping at great with it behind it.

Yeah - shocked how much the 5.3L sucked. I was expecting more from a Truck I guess. All my neighbors say my GL550 is too small to tow that boat and I need a pickup like they have. Then you find out all of them opted for the weakest motors and some of them have lower
tow ratings even in a half-ton

 

Yep... the ignorance of the Americans when it comes to towing is amazing. The GL is the same size as a Tahoe, and larger than a 1/2 ton short bed regular cab. Additionally, most, if not all, 1/2 ton trucks are capped at 5k lbs without weight distribution. SUVs can do 6-8k without weight distribution, generally due to a shorter distance between the hitch and rear axle.

Europeans had trailer sway assist since the early 2000s as part of the ESP. Americans didn't have that until mid-2010s as I recall.

 

The larger size of a full size truck or Suburban is definitley an advantage in terms of "oh shoot" moments... normally. However, in the case of the Merc, the stability control program that works with the braking system to keep it under control is absolutely fantastic. I pushed mine, on purpose, to "get the feel" for it. I did hard, emergency swerve type maneuvers around 50mph to get the system to activate. It worked so well, I had to do it a couple times to make sure it was correct!

Generally speaking, I haven't been overly impressed with the 5.3L and it's power. It just doesn't have enough low end torque and needs higher RPM's to do the job. BUT, I will say, that if a truck/Sub was ordered with the optional rear axle gear ratio option, it does make a difference compared to the standard issue ratio. But still, the 6.2L is noticeably better.

 

 

The weight of the tow vehicle (relative to whats being towed) plays a major role in stability of the combination. GL550 is heavier than a Sierra 1500, and the big V8 in GL550 is very powerful. Air suspension and precise steering makes GL very stable. And the brakes on the GL are just fantastic. The benefit of trucks and body on frame SUVs is that you can put a stout hitch on those and apply serious weight distribution, whereas you cannot do that on a unibody vehicle (The hitch unibody connection cannot handle the weight distribution forces). So, if the tongue weight is not a lot (true for boats, not necessarily true for RV trailers), a unibody vehicle has a more car like ride. But if you are towing heavy, trucks are the way to go (for a variety of reasons, not just the hitch).

 

Mercedes tow bars are very robust. I wouldn't worry about using weight distribution up to the rated tow rating. BMW hitches on the other hand... they're pretty flimsy until you get to the most recent generations.

 

Correct. Mercedes hitches are the best I've seen on unibody vehicles. They are overbuilt. But for heavy tongue weights (e.g., 1000#), you need a proper class 4 hitch, and those can only be attached to a frame.

 

I have a Silverado 2500 HD with the 8.1 L gas motor and it will tow anything like it's nothing. A 1500 series is an emergency tow vehicle in comparison and you're fair in knocking it - you'll have a cushy ride but will feel the load bucking and tugging at every turn. I routinely pull 12,000 lbs with the Silverdong and it's just built to take that kind of abuse.

I have also towed a 6000 lb camper with my GL450 and that was less of a confident experience - I felt every buck and tug, even with a weight distributing hitch. I will probably tow up to 3-4000lbs with it but no more without exceeding my comfort factor. The airnott rear bag theoretical load limit also keeps me from towing more with the GL.

 

Bucking and tugging =/= out of control. I just towed a 4000 lbs boat (total weight) 350 miles with our R500, and it was very comfortable. Some clunking is inevitable with the US hitch design.

 

The GL 550 can tow 7500 pounds?

 

An HD pickup is the ultimate tow vehicle and comparing GL550 to it is not fair. There are also lots of variations in 1500 (axle ratio, engine options, heavy duty payload package, air suspension, etc), and they perform very differently. A properly spec'ed 1500 can tow/haul more than a GL. Pickups are the financially reasonable choice if you tow heavy, too often, and tow in unforgiving terrain (pulling grades in the heat of the summer). A Tundra can tow for 100,000 miles and only requires regular maintenance. A shock absorber replacement on GL costs $1500. So, as always, there is no free lunch. The phenomenal ride quality of GL comes at a price. If you tow infrequently, and less than 6000#, then GL is a great choice -- Its probably the most capable (and comfortable) unibody vehicle out there when it comes to towing.

 

I agree a HD pickup is a different animal and if I did serious towing I would go that route. For me we have the GL550 because it is a good winter beater, good summer tow rig, and carries 7. The last thing being less important as my kids reach driving age. The GL550 is getting up
in age at 9 years old and has 140k on it. We bought it with 110k on it and have towed it a lot. I am impressed with how well it has held up. So far outside of maintenance, it has only had issues with bags going out in the rear and fuel pump. Replace the rear bags was one of the
easiest things I have done to a car. The fuel pump was a pain. I do change oil 2-3 times a year and do a transmission/transaxle/diff drain and fill once a year.

Not sure how much longer we will drive it, but I was thinking of a Tundra/Sequoia as a replacement. The GMC has me seriously questioning that plan and likely will just get another GL550/GLS550.

 

The current Tundra/Sequoia have the same outdated powertrain and design from 2007. It is finally getting a complete overhaul for 2022.

A newer GMC with the 6.2 and 10 speed or a Ford with the Ecoboost and 10 speed will be a better choice than the current Toyota offerings.

 

Some people have had problems with the hitch tearing where the receiver connects to the bar. I added some gussets to mine for piece of mind: https://mbworld.org/forums/gl-class-...ory-hitch.html It has held up fine, but I have probably only towed ~500 miles with it. With a boat/trailer combo that is near the weight limit, it tows it, but you definitely know it is back there. I don't mind pulling it locally, but wouldn't enjoy a longer trip.

 

Correct. But MB stopped putting those faulty hitches on GL in 2011. The replacement is very good/stout.

 

I think Toyota knowingly avoids cutting edge technology to offer unparalleled reliability. Toyota will never be the most efficient, most powerful, most refined, etc, but its usually the most reliable/durable.

 

Excellent. Didn't know they made a change.

 

I think the next gen will be pretty cutting edge, but they run with stuff a long time. I could actually see a new one Toyota if the new generation are as impressive as when the current generation rolled out.

I have no desire for GM/Ford products. My neighbor got a new Suburban this summer. Motor went out at 4k. It dropped a valve. Dealer said it is sadly not that uncommon. They stock the parts/engines.

 

that’s one thing that erodes my comfort factor when towing with the GL - I have not found one draw bar that fits without a lot of slop, or needing shims to quiet the knocking down.

point of my HD comparison was; if you’re gonna tow regularly get something built for it. I will probably tow with my GL but not more than 3-4000 lbs.

 

I'm waiting for Toyota to unveil the specs for the new Tundra so I can decide whether to wait for the new Tundra or buy a current generation one (Our GL350 is retiring from towing duties after 5 years of towing a 6000# camper). My only complaint with current Tundra is the 6 speed transmission. I think you need at least 8 gears for towing. I also really hope they keep the V8, at least as an option. Small displacement turbo V6 engines produce a lot of power/torque, but they have much less engines braking compared to a big V8, which is important for downhill towing. Also, while turbo V6 engines get better MPG driving around town, when under heavy load, they usually get worse MPG that big V8s.

 

You just hear the slop more on a GL because of the unibody construction. Body on frame isolates some of the noise through the body mounts.

The turbo V6 also generally have more torque than the big V8s, especially in the low RPM range. More power and torque = more fuel consumption.

 

Correct. Another problem I've seen with turbo V6 engines is over heating. I have never heard a Tundra or F150 with 5.0 overheat when towing. But I have read multiple reports of EcoBoost overheating when pulling grades in summer.

 

The day I visited the Mercedes test track in Unterturkheim— this is an oval track where the road goes vertical at one end—there was a vehicle towing a trailer on the track. It’s a high speed capable track … has to be to survive the vertical portion. Pretty much all Mercedes are “built for towing” (engineered for towing), but for USA only the SUVs can be factory equipped for towing. There are factory tow hitches for most of the cars for other countries.