Hi!
The GVWR, according to the inside of my door, is 7165.

The curb weight, according to MB that I emailed to double check is 5400- cant find the exact number for my particular vehicle anywhere and havent been to the scale yet.

Payload should then be 1765, right??

So why does the sticker inside my door say the maximum of all occupants and cargo is 1245?? That is QUITE a difference!

 

Gross vehicle weight (GVW) is gross vehicle weight, it doesn't matter how you get there. It is a rating from the manufacturer indicating the highest weight the body + chassis + powertrain can support and transport safely and reliably.

Exceeding GVW puts the tires, springs, body structure and transmission into a higher-than-designed loading condition. Operating the vehicle beyond GVW may be unpredictable, and at worst, unsafe. Damage may occur, or it may not.

If 500 lbs means something to you, you can go to a truck scale (Pilot, Flying J, Travel America, Petro, or some ag facilities such as grain elevators).

Measure your vehicle weight, and deduct that from GVW and you will know the remaining additional weight (payload, people, lead, feathers, bricks, etc.).

Fluids need to be topped up, and are counted in GVW. In other words, if you load a vehicle to GVW with an empty fuel tank, then fill the fuel tank, technically this results in an overload condition.

 

I wonder if the tounge weight of a trailer is also included in the formula?

 

Yes it is. Gross vehicle weight is the maximum of the two axle weights.

Front axle weight = lbs or kgs on the two front tires
rear axle weight = lbs or kgs on the two rear tires

GVW is GVW, it’s doesn't matter how you get there. It doesn’t matter if tongue weight is present or not.

GCW is gross combination weight which includes the weight of the towed device. GVW does not change when considering GCW. GCW is specified by the manufacturer, in large part, to match the towed load to braking and drivetrain (transmission) performance.

GCW = front axle weight + rear axle weight + weight of all towed device’s axles

It doesn’t matter if the vehicle is filled with helium and the trailer is filled with monkeys or gold boullion. Weight is weight.

 

Uh, yeah, thanks for that. (I understand GVW and regularly deal with loading machines drastically more complicated than the X166. )

I should have been more specific, and am wondering if if the apparently large difference between the interior passenger/cargo placarded limit and GVW is there to provide an allowance for tongue weight?

Combine the interior loading limit, empty vehicle weight, and tongue limit weight. All combined there suddenly is not the previously huge difference from GVW that the OP noticed.

The apparent discrepancy between GVW and interior loading limit is the heart of the OP's question, no?

 

Max payload for a 2014 GL450 is 1764 lbs. Max towing is 7500 lbs.

 

Yup, which brings us back full circle to Myszko's question.

FWIW, our 2014 GL350 has this placard on the driver's door:

"The combined weight of occupants and cargo should never exceed 1179 lbs."

 

Mine says 1168 lbs. But since its referring to tire load, I'm not concerned about it. I have XL tires and they can handle more than the combined weight of the vehicle (5800 lbs) plus 1168 payload between the 4 corners.

 

It's more than the tires, its also the air suspension you should consider. I once squeezed a whole pallet of wood pellets (2000lbs) in my ML and drove them 6 miles home squatting much lower than I've seen before. Could be just a coincidence but my right rear air suspension needed replacement months later.

 

Sorry this thread is almost a year old but it did not seem to fully resolve the OP's question so rather than starting a new thread I will add on to this and see if that generates a definitive answer.

I have the same question about the difference between PAYLOAD on a US 2020 GLS450 which I believe should be GVWR 7275# minus curb weight 5412# = 1863 (correct?).

Vs. what is on the door sticker which in my case is only 1301# so a difference of 562# .

Note I'm not sure whether the curb weight or door sticker numbers account for full tank of fuel or not. I assume they both do so apples to apples.

Either way, towing a trailer at the full hitch tongue weight limit of only 617 pounds, 1301#-617# = 684# does not leave a lot for pax and cargo. Average US male 200# and female 170# (!) = 370# . So you would only have 314# left for cargo. Maybe that's enough but it's not 1863#.

My question is whether the difference between payload calculation and the door sticker is 100% because the door sticker numbers are based on the weight limitations of the stock tires? So if you replace the stock tires with higher rated tires as poster above did, that you'd get the full payload back?

Or are there other explanations?

Seems that to realize the full 7700# towing capability of the 2020 GLS450 and carry a normal load of cargo, you would need to do 2 things...reinforce the weak hitch which seems mismatched at only 617# (should be at least 10% of the towing limit or 770#) AND possibly upgrade the tires... Reinforcing the hitch is not straightforward on a unibody vehicle, would depend on who does it and how and might void the warranty on the frame, suspension, transmission or engine if you have problems. Upgrading the tires would probably negatively impact the smooth ride.

Without those, the real towing capability is more like 6170 pounds because you need 10% of towed weight on the hitch to avoid trailer sway.

Thoughts?

 

Payload = GVWR - Curb weight.

The curb weight that Mercedes gave you is for a bare bone GL (without any option). You cannot find such a GL on a dealer lot, as everybody wants moonroof, heated seats, etc. Those options increase the curb weight (and reduce the payload). You can take your GL, with a full tank of fuel, to a CAT scale and weigh it. I have a 2012 GL 350, which I weighed. The yellow sticker on door says the payload is 1157#. The scale measurements say 1200#. Part of this small difference could be due to the scale error. GL 450 has a gas engine, which is lighter than the Diesel engine in GL350. So, I expect your GL to be lighter and have a higher payload (my guess would be closer to 1400#, but you need to weigh it to verify).

 

GL's hitch limit is 600#. Since a trailer's tongue weight should be at least 10% of the trailer gross weight, that limits you to a 6000# trailer. You can tow a 7500# boat trailer (those have lighter tongue weights, around 8%) and utilize the full 7500# towing capacity.

You will not find a single unibody vehicle with hitch limit of 800#. Unibody vehicles are not designed for forces applied by weight distribution hitches. You need a vehicle with a frame for that. I've seen a reinforcement done by a shop in Canada. I contacted them and asked them what would be the rating of the reinforced hitch? They would not provide an answer. Worse than that, they weld a brace between the hitch receiver tube and the axle carrier. The problem is that hitch receiver is attached to unibody, whereas axle carrier can move independently of the unibody. Axle carrier also is not designed to handle such forces and can crack, which is expensive to repair and can cause loss of control (some BMW sport cars had this problem years ago). GL is a very, very stable tow vehicle, but its not a pickup and is limited in tongue weight limit, and payload (what you can carry with you inside GL). It can tow a 6000# trailer very well, but thats the upper limit, in my experience, unless you are willing to give up performance (drive slower, etc), OR if you live in an area that if flat/cool and you only tow occasionally. For mountain towing, I would stick to 6000# (80% rule). I don't think changing tires would increase the payload. There are other limiting factors (suspension comes to mind).
P.S. I showed a photo of the hitch reinforcement to my service manager and he said part of my warranty would be voided. Your milage may vary.

 

Thank you, I tend to agree with you. While it would certainly be possible to make it work with the GLS450, after considering all the factors and discussing with my better half, we are about to pull the trigger on a used SD pickup truck designed for towing to replace our 17 year old 2nd car. Why?

• As you point out, the actual weights and capacities of both the SUV and my trailer are different than specifications even when empty
  • I knew they would be different, but I didn't expect them to be this far off
• My trailer's total weight is not far off, but the actual tongue weight of 1145# is 30% more than spec 830# That's huge.
  • Even if I re-balance cargo, it would still be way over the GLS450 hitch spec of 617# especially when loaded.
  • I made the mistake of assuming the GLS450 hitch would be strong enough to handle at least 10% of it's 7700 tow capacity or 770# since 10-15% TW is what's recommended to avoid sway vs. 617# rating hat I finally found in an online owner manual.
• Additionally I misunderstood and thought that a WDH would help reduce the weight on the hitch, but I now know it does not
  • Even worse, I have read posts that say it increases the stress on the hitch due to torque and twisting, which seems to make sense
• So instead of an negligible excess 60# (830# spec tongue weight vs. 770# assumed hitch rating ) which I thought would be mitigated by a WDH, I have a significant excess of 528# (1145# actual tongue weight-617# actual hitch rating) that could be exacerbated by the WDH
• Which means that I would need to significantly reinforce the stock hitch to almost 2X it's rating
• With the borders closed indefinitely and living 1800 miles away in Utah, I can't get to Andy in Canada anytime soon.
  • If I could get to Andy it might be a different story!
• So I would be relying on someone local whom I don't know with much less experience, and no guarantees as you point out
  • Like you I saw pictures of the hitch reinforcements on unibody vehicles such as the Touareg and the potential tricky issues they raise
• I do not want to risk voiding the warranty on my GLS450
• Subjective, I really like the GLS and do not want to wear it out by towing a trailer at its limit up and down the mountains where I live

And of course the deciding factor was after explaining all this to my wiser, better half she simply said "that all sounds interesting...I'll drive the GLS, and you go get something for the trailer"

I really wanted to make the GLS work, but it was wishful thinking on paper vs. reality at every turn. If I had to do it all over again I would weigh the trailer and tow vehicle before buying them and also make a thorough list of what we would typically carry with estimated weights to confirm it would work.

Please correct anything that's wrong. Maybe will help someone else.

 

I think you are doing the right thing. 1145# tongue weight is not only near double the rating of a GLS hitch, but, IMO, is also WAY too much weight for its rear suspension. I'd think a pickup with solid axle would do better with that much weight than GLS with independent suspension (That much weight on an independent suspension, and you might lose control or jackknife when doing an emergency maneuver or hard braking). I think a HD truck would do even better than a 1/2 ton pickup for that tongue weight. Mercedes dealership charges $1200 to replace each rear shock absorber. You can overload them, but there is a price to pay.

I've have towed almost 5 years now with GL, towing a 6000# trailer. GL is as comfortable and stable a tow vehicle as you can find. The brakes are phenomenal. It certainly punches above its weight class. My next tow vehicle would be a pickup though. Sure, pickups don't have the silky ride of GLS (or its luxury/comfort), but you can buy a nice Tundra with half the price of GLS. Tundra's maintenance cost is also half GLS', and the repair cost is significantly less (that's if Tundra ever breaks). While GLS can tow a 6000# trailer as good as any pickup, pickups have higher tow rating and can tow heavier trailers. They also have more payload, higher rated hitches, etc. You are not at the limit of your vehicle, and don't have to constantly think about various numbers/limits. You don't have to modify a pickup.

There are other practical considerations. GLS is relatively narrow and you need tow mirrors. I HATE attaching clip-on tow mirrors (If I'm not careful, they would vibrate). With a pickup, they are wider and you get integrated tow mirror (such a relief). Also, I need to connect/disconnect the break controller for every trip. Again, pickup has integrated brake controller. Also, carrying the grill, firewood, chairs, fuel, etc in GL's trunk is not ideal. With pickups, you have a bed you can use. Having low range and lockers is also a plus for pickups (I know some GLS models have it). We were camping in a remote campground, and I was concerned whether GL's full time AWD is enough to get us to the state park or not. The cooling system in pickups is also superior to GLS. Comes in handy when you are towing up a grade in the heat of the summer.

In summary, I'll probably buy 1/2 ton (or 3/4 ton gas pickup) when our GL retires from towing duties. I believe a pickup is superior to GLS for towing duties (that's expected, as its designed for this). For everything else but towing/hauling, GLS is superior