This M-Class tows an Airbus at the Stuttgart airport. Photo: Mercedes-Benz

"Extra safety in critical situations is guaranteed if the towing vehicle is equipped with ESP." Conti-Teves For towing the frame based W163 M-Class may be preferable over the unit-body W164, using the frame rails for towing instead of the body.

Towing Capacity

	Mercedes-Benz model		towing capacity incl. tongue weight	maximum tongue weight	speed limit
USA	ML320 (W163) ML350 ML430 ML500 ML55 AMG		5000 lbs Class III	500 lbs	55 MPH - 88 km/h applies to all vehicles with trailers in CA VC 22406
	ML350 (W164) ML500 ML320 CDI/BlueTEC ML63 AMG ML550		7200 lbs Class III (starting MY2007?)
	G500 (W463) G55 AMG		7000 lbs Class IV	700 lbs
	GL450 (X164) GL320 CDI/BlueTEC GL550		7500 lbs Class III + IV	600 lbs
	GLK350 (X204) GLK350 4MATIC		3500 lbs Class II	350 lbs
	R350 (W251) R320 BlueTEC		3500 lbs Class II (starting MY2009)	350 lbs
Germany	A-Class L	2205 lbs - 1000 kg1	at least 4% of trailer weight	50 MPH 80 km/h applies to all vehicles with trailers 62 MPH 100 km/h applies to tow vehicles with 4 wheel ABS
	W114 W115 SL (R107) 1975 S-Class (W116) W201	2650 lbs - 1200 kg
	190E C-Class (W202) CLK W123 SL (R107) 1983 SL (R129) S-Class (W126)	3305 lbs - 1500 kg	165 lbs - 75 kg to 220 lbs - 100 kg
	CL E-Class (W124) E-Class (W124) T-model stick E-Class (W210) E-Class (W211) S-Class (W126)2 S-Class (W140) stick	4190 lbs - 1900 kg	167 lbs - 76 kg
	V-Class	4410 lbs - 2000 kg
	E-Class (W124) T-model auto E-Class (W210) 2 S-Class (W140) auto S-Class L (V220) S-Class (W221) R280 CDI (W251) R320 CDI R350 R500 R63 AMG	4630 lbs - 2100 kg
	G270 CDI (W463) G400 CDI G320 G500	2850 kg - 3360 kg	140 kg
	ML230	6615 lbs - 3000 kg	275 lbs - 125 kg
	ML270 CDI (W163) ML320 ML350 ML430 ML500 ML400 CDI ML55 AMG ML280 CDI (W164) ML320 CDI ML420 CDI ML350 ML500 ML63 AMG GL320 CDI (X164) GL420 CDI GL450 GL500	7715 lbs - 3500 kg	300 lbs - 135 kg

¹ trailer brakes required over 880 lbs or 400 kg
² with special permit (meaning it's fine for the occasional horse trailer, but not for every day use)

Trailer brakes are required above 1655 lbs or 750 kg. Electric trailer brakes require a brake controller.
Many boat trailers have surge brakes, not requiring electric controllers.

Handling and braking response in commercial vehicles
Jack-knifing is also a danger when tractor trailer combinations are braked in extreme situations. This process is characterized by loss of lateral traction at the tractor's rear axle, and is triggered when overbraking on slippery road surfaces, or by extreme yaw rates on mu-split surfaces (with different friction coefficients at the center and on the shoulder of the lane). Jack-knifing can be avoided with the aid of antilock braking systems (ABS). -- Bosch (1998)

Tow hooks for the W163 M-Class
W163 M-Class (1998 to 2005) OEM Hitch (made by Oris) and harness install instructions (1.3 MB pdf) Mercedes part number Q6-31-0002

Draw Tite Hitch for W163 M-Class (1998 to 2005) install instructions (305 kB pdf)
All pdf files provided by Charles Alt. Thanks!

The wiring harness plugs into the connector in the M-Class.
Q-6-54-0013 harness with three inbound plugs
Q-6-54-0014 PCB Assembly connects to 2 of those
Q-6-54-0015 outside Pollak Plug
Q-6-84-0033 bracket for outside plug
Part numbers provided by Peter in Arizona

If you also want to install a brake controller, follow these instructions:
W163 M-Class (1998 to 2005) Brake Controller Wiring (104 kB, pdf)

Pollak USA trailer plug pink right turn signal gray backup lamp red + power fuse 18 white taillamp orange stop lamp; or brake controller brown - ground green left turn signal

Trailer Hitch Installation info on off-road.com

Oris Automotive
They build the factory hitches for the M-Class.

Brenderup Real Trailers
"The World's Easiest handling Full Sized One and Two-Horse Trailers. Available in the United States since 1982."

Advanced Accessory Systems / Brink

Champion Trailers/Classic Mfg

New M-Class (W164) with Trailer Stability Assist (TSA)
The factory-fitted package of measures will in future include the new Mercedes-Benz Trailer Stability Assist (TSA). This is an extra function incorporated into the ESP® Electronic Stability Program that is designed to offer drivers even greater safety when towing a trailer. TSA is capable of detecting the dreaded fishtailing motion swiftly and nipping it in the bud effectively. To do this, it uses the ESP® program's own sensory system and initiates precision brake applications at the front left and right wheels individually and alternately to stabilise the car/trailer outfit. TSA will be added to the specification of the M-Class from late August 2005.
from a Mercedes press release dated July 7, 2005.

Trailer Brake Controller Installation in new ML, R and GL
A dealer technical bulletin (DTB) dated Mar 9, 2007 with number T-B-31.19/07d describes how to install an Electric Trailer Brake Controller. The bulletin is for the new W164 M-Class and X164 GL, but might also work for the W251 R-Class.
Four wires are required to operate the electric brake controller. These four wires can be found on a plug tie wrapped to the harness leading to the diagnostic plug under the dash. On early production vehicles until December 2006 the plug was stuffed behind the rear SAM (see the green plug X58/28 in the picture above) and sometimes difficult to locate.

rameder Anhängerkupplung (Germany) kupplung.de
They have a tow hook for the new W164 M-Class.

Hidden Hitch makes a trailer hitch for the R-Class with 3500 lbs capacity. Part number 87413.

Draw-Tite model 75470 for the R-Class also has a 3500 lbs capacity.

shoptalk

Schleppen macht den Kohl fett.

Wolfgang's MB Page