After owning my GL320 for many years, and having 135000 miles, I finally started towing a 6200lb+ , 27 ft end-to-end long travel trailer, and here are my thoughts. I am blown away of how well the vehicle tows, I went up and down Mt passes and the car is super stabile. I have a load leveling hitch and a sway stabilizer installed on one side. I am using the Prodigy RF wireless brake controller, so I did not have to mess with wires. I even strapped my dirt bike on the bumper, and had no issues! I could go 60 mph up a steep mt passes, and rpms were 2400. On the flat highway 19000 RPMs and 65mph is a breeze, you can barely tell the trailer is there. Sure, you don’t accelerate fast, steeper on -ramps will take you into the 3500 rpms to get up to speed, and stopping takes longer, but that is normal. The best part, my mpg is 13-14 when towing, with speeds 60-65mph. My camper neighbor on my last trip had a 2012 Silverado 25000 HD duramax 6.2L diesel, towing similar trailer and he said that his MPG was 13-14 – same as mine !!!? I am sure his mpg will stay the same with heavier trailer, and mine will go up, but still! One more thing, the problematic and often breaking air suspension works beautifully when it is working, it auto levels the rig and keeps is firm and stable – very nice! Mine is all replaced with Arnott on all 4, and I had to put a new compressor few years ago. Also, after towing , my car feel fast, no joke, it is faster, I think the towing blew out some carbon, or something.., not sure, but it feels snappier for sure. I don’t typically drive it long distance, and I know our engines like e the open throttle from time to time.

 

I have towed travel trailer a little bit longer and slightly lighter with my GL450. That was a rental travel trailer and that was the first time I was towing. About 1600 miles round trip.

Before towing, I was hesitating and asked in some RV forum, people there all told me that it was too short a wheel base to tow a trailer that long, that heavy, blah blah ... I sincerely believe in their kindness and know they wanted me to be safe. But after checking forums with GL owners with towing experience, I decided to go ahead.

The towing was very stable! Not even for a second did I feel any swing, nor was I bothered by wind or big trucks passing by.

GL's towing is mainly limited by its payload capacity (passengers, cargo in it, and tongue weight etc). But when everything is within its limit, it really tows well!

 

I will jump on this as well. My towing experience is first with the 320 and more recently with the 550 and I cannot sing enough good praises on how well this platform tows. I tow open trailer with usually a race car on it so the weigh is well within spec. The setup is very steady on highway and hassle free due to leveling suspension (best feature on truck if you tow!). The GL also maintains its comfortable ride. I would have slight preference for the diesel for towing obviously but can tell you the 550 is no slouch either. Just have to deal with worse MPGs. Oh and one more gripe is that the 550 doesn't like LED lights on the trailer so i had to buy a module to get them to work right. That's about it!

 

What I tow ... obviously easily. Must admit that unit once saw 90 mph passing an 18-wheeler in the Oklahoma panhandle, not a compliment to my intelligence.

This trailer has surge brakes but I've anyway retrofitted the wiring harness for electric brake controller to both this one and stepdaughter's GL450 for horse trailer towing. Both our vehicles are early '07 production which didn't include that wiring harness, but you can buy it from Mercedes and retrofit it.

 

I will have to agree with you. I drove a 25' travel trailer from Florida to Missouri in one day and it handled it amazingly! I only got about 12-14mpg however, I have 190k miles on the original DPF which I know needs to be cleaned. It automatically leveled itself and made it seamless to haul the trailer. I did not use any sway control or stabilizers and use the Tekonsha 90160 Primus IQ Electronic Brake Control and hooded it up to the already ran wires under the dash. I am guessing it was about 4500lbs with the trailer and all of the equipment and it felt like it was barely there. The only time I felt the trailer sway was on long downhills when a semi passed me. I just squeezed the manual brake on the controller and it immediately stopped swaying. I was really impressed with this little diesel and the luxury of it was hands down. In the picture, the car is on a slight incline. Once on level ground, it was as level as the road.

 

Love my GL320. 208k on the clock and still going strong. Granted i've done an obscene amount of repairs but I still love it.

 

I love the black color!
What kind of repairs have you done?

 

*deep breath* here we go:
Brake pads, rotors, front axles, front diff, oil cooler, egr, dpf sensor, EGT sensor, 3 injectors, transmission front pump, panoramic sunroof, front air shocks, driveshaft flex disc, and a countless number of other things ive forgotten.

The panoramic sunroof was the most costly ($4500) but luckily my glass insurance took care of it for a small deductible ($50). Its plastic and had cracks in it from sitting in the sun for 11 years. Was leaking water in to the rear wheelwells. Its a dealer only replacement item.

If you have not checked yours for cracks, do so soon.

 

My GL550 tows awesome. I tow a Yamaha AR210 with it. I get about 12mpg. I towed with ah Audi Q7 4.2L before this. It did fine, but got 8mpg and didn't have enough low-end torque. It required running 5th gear most of the time. (6 speed transmission)