Our towing experience with GL320CDI
Thread Starter
Senior Member
Joined: Jul 2007
Posts: 297
Likes: 4
From: Bay Area CA
2014 GL 350 blue tec
Our towing experience with GL320CDI
Past summer we were trying to decide between a Yukon XL and GL 320 CDi.. there were many posts on this site which cautioned about towing anything heavy with GL.. I was concnerned but went ahead and bought the GL anyways. Well this morning I finally had the opprtunity to tow my boat, total weight 7000 lbs , maybe a bit more.. It was absolutely a pleasure towing with GL 320CDI.. As a matter of fact, I think it tows even better than Yukon XL (we have owned Suburban and Yukons for 10 years). Under that "refined" and "sophisticated" personality is an absolute beast. Lots of torque, real smooth riding (love the air suspension). Towed our boat 200 plus miles ,,our route was a mix of small towns, freeways and highways. Average gas mileage per the on board computer 13.8 Mpg , same route without boat we get 20.8 mpg,, so not bad at all.. Infact 13.8 mpg is same as Yukon Xl on a good day.
Those wondering if this SUV is strong enough to tow, we were doing 75mph on freeway with engine rpms at 2100.. so plenty of spare power and torque. I have attached couple of pics of my set up . Our trailer has hydraulic surge breaks.
Those wondering if this SUV is strong enough to tow, we were doing 75mph on freeway with engine rpms at 2100.. so plenty of spare power and torque. I have attached couple of pics of my set up . Our trailer has hydraulic surge breaks.
Last edited by infamily; Oct 22, 2007 at 08:52 PM.
MBWorld Fanatic!
Joined: Apr 2007
Posts: 1,046
Likes: 1
From: Colorado Rocky Mtns.
'06 A6 & '08 GL550
Beautiful boat and it looks great with the GL.
Glad to hear you had a great experience and that your purchase was a wise decision. Enjoy every moment with both your toys!
Glad to hear you had a great experience and that your purchase was a wise decision. Enjoy every moment with both your toys!
MBWorld Fanatic!
Joined: May 2007
Posts: 2,244
Likes: 1
From: Scottsdale, AZ
2004 RX330, 2008 Scion xB, 2001 Honda Insight Hybrid, 2010 Toyot Prius v ATP
Newbie
Joined: May 2009
Posts: 8
Likes: 0
GL320
09 GL320
I have an 09 GL320 with the towing package, but need an electronic brake controller. The Benz dealer her in Greenville SC is clueless. I got the plug and pins, but I wonder if the vehicle has to be reprogrammed if I install a brake controller?
Anyone have experience with this?
Thanks.
Anyone have experience with this?
Thanks.
Super Member
Joined: Feb 2009
Posts: 711
Likes: 11
From: NW corner of CONUS
2008 GL 320 CDI, 2004 VW V10 Touareg TDI
I have an 09 GL320 with the towing package, but need an electronic brake controller. The Benz dealer her in Greenville SC is clueless. I got the plug and pins, but I wonder if the vehicle has to be reprogrammed if I install a brake controller?
Anyone have experience with this?
Thanks.
Anyone have experience with this?
Thanks.
A good proportional controller is adjustable with a knob or dial to activate the trailer brakes in proportion to the brake pedal pressure. To do this it must be mounted in easy reach of the driver.
Newbie
Joined: Mar 2009
Posts: 11
Likes: 0
From: New Jersey
GL320
I installed a Prodigy® RF Electronic Brake Control, for 1 to 3 Axle Trailers
Works Great had my dealer install it Plug & Play install.
http://www.tekonsha.com/product/acce...ontrols&#P3%AE
I tow the toys all over the country side with my GL320 tow's like a champ.
Works Great had my dealer install it Plug & Play install.
http://www.tekonsha.com/product/acce...ontrols&#P3%AE
I tow the toys all over the country side with my GL320 tow's like a champ.
I have an 09 GL320 with the towing package, but need an electronic brake controller. The Benz dealer her in Greenville SC is clueless. I got the plug and pins, but I wonder if the vehicle has to be reprogrammed if I install a brake controller?
Anyone have experience with this?
Thanks.
Anyone have experience with this?
Thanks.
Newbie
Joined: May 2009
Posts: 8
Likes: 0
GL320
Controller
Finally got the plug/pins from the dealer who initially told me there was no such thing. Picked up a Prodigy and soldered the pins, put together the plug and mounted it in about 30 minutes total. Looking forward to using my trailer again.
Thanks for the comments.
Thanks for the comments.
Trending Topics
Member
Joined: Aug 2008
Posts: 210
Likes: 13
From: Louisville, KY
2014 Black SLK 55 AMG, Black 2015 GL 550, 2011 Blue GLK 350
I have pulled a +/- 5000 lb 22 ft. center console boat with a 07 ML 320 CDI and an 08 GL 320 CDI. The torque is incredible. I have passed Suburbans and Expeditions pulling similiar sized boats on long steep hills going 75 MPH and they pass me later on the flat road as I maintain speed and they cant on the hills. I simply love the power and economy of the GL 320. I average about 12 MPG pulling the boat as it has a very high T-top that has significant drag. I pulled the same rig with a V8 Explorer that got 8 MPG. I have a tandem axle trailer with surge disc brakes on all 4 wheels. No problems stopping at all. Very comfortable ride due to the air ride suspension.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: May 2007
Posts: 2,244
Likes: 1
From: Scottsdale, AZ
2004 RX330, 2008 Scion xB, 2001 Honda Insight Hybrid, 2010 Toyot Prius v ATP
Super Member
Joined: Aug 2007
Posts: 603
Likes: 0
From: Spicewood, TX
2008 GL 320, 2007 Silverado LTZ C3500 Duramax Turbo Diesel
I had a 11,000 lb. (2 x 5500lb axles) utility trailer with surge brakes. We liked it because we didn't need to put controllers on all the crew trucks. I don't know if I would go any heavier than that.
Senior Member
Joined: Dec 2006
Posts: 405
Likes: 1
From: Scottsdale, AZ
2007 GL320 CDI, 2001 TJ Rockcrawler, 2005 Scoobie STI
Surge brakes are a fine option... Especially for boat trailers that get dipped in the water where the brake wiring would corrode quickly from the exposure to moisture.
However, electronic brakes are superior, if for no other reason than the fact that you can actuate them independently from the vehicles brakes using the controller...
In the case where you have a badly swaying trailer, using the vehicles brakes can actually exacerbate the problem and possibly result in a total loss of control... In that situation, you can apply just the trailer's brakes, independently, using the controller and it will bring the sway under control.
Surge brakes only work in conjunction with applying the tow vehicles brakes or downshifting the tow vehicle's transmission.
However, electronic brakes are superior, if for no other reason than the fact that you can actuate them independently from the vehicles brakes using the controller...
In the case where you have a badly swaying trailer, using the vehicles brakes can actually exacerbate the problem and possibly result in a total loss of control... In that situation, you can apply just the trailer's brakes, independently, using the controller and it will bring the sway under control.
Surge brakes only work in conjunction with applying the tow vehicles brakes or downshifting the tow vehicle's transmission.
Super Member
Joined: Aug 2007
Posts: 603
Likes: 0
From: Spicewood, TX
2008 GL 320, 2007 Silverado LTZ C3500 Duramax Turbo Diesel
Surge brakes are a fine option... Especially for boat trailers that get dipped in the water where the brake wiring would corrode quickly from the exposure to moisture.
However, electronic brakes are superior, if for no other reason than the fact that you can actuate them independently from the vehicles brakes using the controller...
In the case where you have a badly swaying trailer, using the vehicles brakes can actually exacerbate the problem and possibly result in a total loss of control... In that situation, you can apply just the trailer's brakes, independently, using the controller and it will bring the sway under control.
Surge brakes only work in conjunction with applying the tow vehicles brakes or downshifting the tow vehicle's transmission.
However, electronic brakes are superior, if for no other reason than the fact that you can actuate them independently from the vehicles brakes using the controller...
In the case where you have a badly swaying trailer, using the vehicles brakes can actually exacerbate the problem and possibly result in a total loss of control... In that situation, you can apply just the trailer's brakes, independently, using the controller and it will bring the sway under control.
Surge brakes only work in conjunction with applying the tow vehicles brakes or downshifting the tow vehicle's transmission.
Junior Member
Joined: Jan 2010
Posts: 54
Likes: 0
From: SW Washington
07 GL320 CDI
first post and I want to revisit this thread...
Strongly considering an 07 GL320cdi to replace the expedition. We'd like to use it for a little local towing like we did with the EX. We tow an enclosed race trailer and its not real heavy (maybe 6500# loaded), but toolboxes, etc make the tongue a little heavy-- approx. 700-800 lbs. We have a weight distribution receiver for the EX and its worked fine. My concern has been using the WD receiver with the GLs hitch and if it would be able to handle the load.
Any experienced users out there?
Strongly considering an 07 GL320cdi to replace the expedition. We'd like to use it for a little local towing like we did with the EX. We tow an enclosed race trailer and its not real heavy (maybe 6500# loaded), but toolboxes, etc make the tongue a little heavy-- approx. 700-800 lbs. We have a weight distribution receiver for the EX and its worked fine. My concern has been using the WD receiver with the GLs hitch and if it would be able to handle the load.
Any experienced users out there?
Junior Member
Joined: Jul 2009
Posts: 24
Likes: 0
2009 GL320 Bluetec
No, the GL's hitch cannot take a 700-800 lb load. It is placarded to a limit of 600 lbs and believe me, they mean it.
You'll have to reinforce the hitch to carry that tongue weight. Get an experienced custom hitch company (hard to find these days). The load must be spread out to avoid overstressing the bottom pan of the unibody, and to make up for the very wimpy welded connections between the receiver box and the main tube.
Here's how we did it... YMMV
You'll have to reinforce the hitch to carry that tongue weight. Get an experienced custom hitch company (hard to find these days). The load must be spread out to avoid overstressing the bottom pan of the unibody, and to make up for the very wimpy welded connections between the receiver box and the main tube.
Here's how we did it... YMMV
MBWorld Fanatic!
Joined: May 2007
Posts: 2,244
Likes: 1
From: Scottsdale, AZ
2004 RX330, 2008 Scion xB, 2001 Honda Insight Hybrid, 2010 Toyot Prius v ATP
You'll have to reinforce the hitch to carry that tongue weight. Get an experienced custom hitch company (hard to find these days). The load must be spread out to avoid overstressing the bottom pan of the unibody, and to make up for the very wimpy welded connections between the receiver box and the main tube.
STP
Junior Member
Joined: Jan 2010
Posts: 54
Likes: 0
From: SW Washington
07 GL320 CDI
This is getting interesting...
I'm taking delivery of my GL today....I've seen some pics on this forum of pretty big loads pulled with these rigs. I'd like to do the same but I'm not sure. My old truck may get pressed back into service.
Based on what I've learned so far, the GLs hitch is not hooked up to an actual frame, but rather the unibody. This rig looks very capable on paper, but may not be as capable as a domestic SUV due to its design. Making major modifications to the factory hitch assembly seems like a liability disaster.
With any race car trailer, getting weight off the tongue is difficult. Your tools,tires,accessories are always up front and enclosed trailers are worse.
Does MB even recommend a distribution hitch regardless of weight? The weight distribution receiver spreads the load further forward on the tow vehicle, but puts a counter-clockwise/upward torsional load on the hitch, receiver tube, and vehicle mount location.
Iridium has an interesting hitch idea but I'm not sure I'm ready to take responsiblity for re-engineering this vehicle. What have others done?? Please keep the discussion going....
I'm taking delivery of my GL today....I've seen some pics on this forum of pretty big loads pulled with these rigs. I'd like to do the same but I'm not sure. My old truck may get pressed back into service.
Based on what I've learned so far, the GLs hitch is not hooked up to an actual frame, but rather the unibody. This rig looks very capable on paper, but may not be as capable as a domestic SUV due to its design. Making major modifications to the factory hitch assembly seems like a liability disaster.
With any race car trailer, getting weight off the tongue is difficult. Your tools,tires,accessories are always up front and enclosed trailers are worse.
Does MB even recommend a distribution hitch regardless of weight? The weight distribution receiver spreads the load further forward on the tow vehicle, but puts a counter-clockwise/upward torsional load on the hitch, receiver tube, and vehicle mount location.
Iridium has an interesting hitch idea but I'm not sure I'm ready to take responsiblity for re-engineering this vehicle. What have others done?? Please keep the discussion going....
Junior Member
Joined: Jul 2009
Posts: 24
Likes: 0
2009 GL320 Bluetec
Removing tongue weight by redistributing the load can be very dangerous. Tongue weight must remain in a safe range or the trailer can become unstable and/or sway out of control. Generally experts in the US recommend 8-12% tongue weight.
Mercedes has apparently designed their hitch for 8%, because the hitch is placarded for 7500 lbs total trailer weight and 600 lbs of tongue weight (8%). You will find that 600 lbs of tongue weight changes the steering characteristics of the vehicle dramatically (and I would say unsafely) without a weight distributing hitch.
STP, the hitch recall did not apply to 2009 and later model year GLs, but the welds to the main (round) tube are still inadequate in my opinion. Take a look at them yourself and see what you think.
Mercedes has apparently designed their hitch for 8%, because the hitch is placarded for 7500 lbs total trailer weight and 600 lbs of tongue weight (8%). You will find that 600 lbs of tongue weight changes the steering characteristics of the vehicle dramatically (and I would say unsafely) without a weight distributing hitch.
STP, the hitch recall did not apply to 2009 and later model year GLs, but the welds to the main (round) tube are still inadequate in my opinion. Take a look at them yourself and see what you think.
Junior Member
Joined: Jan 2010
Posts: 54
Likes: 0
From: SW Washington
07 GL320 CDI
Iridium, how did you attach the front bar in your modification? I'd like to know more..
Guys,
I haven't studied my hitch yet (to make real strength opinions), but the receiver tube on my 3/4ton's hitch is only welded in 2 points. My biggest concern is the attachment of the hitch to the unibody. I found the pics of the large twinhull fishing boat to be very interesting-- that tongue has to have weight in excess of 600 lbs and has no distribution components, all gravity. The air suspension does look pretty stout to keep the rig level under that weight.
I would really like to put my trailer behind the GL-- my old powerstroke isn't very comfortable in the 150 mile round trips to the track anymore. Perhaps a lighter trailer is in the cards....
thanks for the notes!
Guys,
I haven't studied my hitch yet (to make real strength opinions), but the receiver tube on my 3/4ton's hitch is only welded in 2 points. My biggest concern is the attachment of the hitch to the unibody. I found the pics of the large twinhull fishing boat to be very interesting-- that tongue has to have weight in excess of 600 lbs and has no distribution components, all gravity. The air suspension does look pretty stout to keep the rig level under that weight.
I would really like to put my trailer behind the GL-- my old powerstroke isn't very comfortable in the 150 mile round trips to the track anymore. Perhaps a lighter trailer is in the cards....
thanks for the notes!
Super Member
Joined: Feb 2009
Posts: 711
Likes: 11
From: NW corner of CONUS
2008 GL 320 CDI, 2004 VW V10 Touareg TDI
The automatic suspension leveling negates the need for a weight distribution hitch in most applications - unlike your Powerstroke or most other trucks. The hitch recall to repair/replace possible undersize factory welds should be adequate to handle the tongue loads specified. Keep in mind that total trailer weight (mass) is the controlling design consideration for the strength of the receiver. The rotational moment of inertia of the trailer about the wheel(s) axis contributes most of the load the hitch has to bear. (think of a road like the 'whoop-de-dos' on a motocross track)
Junior Member
Joined: Jan 2010
Posts: 54
Likes: 0
From: SW Washington
07 GL320 CDI
After having gotten this new acquisition in our driveway and looked closer at the hitch, I feel much better. The recall repairs were done quite well and was definitely not 'joe bob with a tig and a spool of wire'. This hitch is every bit as reinforced as the class IV hitch on the old truck.
Bearing in mind, I'm not doing cross country (or even regional) trips with this set up. Our Foretravel pusher pulls the trailer to the farther locations. This will just be for making day trips to local tracks.
My plan right now is to get the trailer over to the scales to confirm tongue weight. If below 650lbs, I won't worry about it. If over 675, then I'll think about how I could move contents around. Then I'll post pics of the GL pulling a 28' car trailer...
On the weight distribution bars, I still plan to use them (not heavily cranked up) to eliminate the 'hobby horse' fore/aft movement when going over the 'whoops'. The suspension will get a little workout.
Bearing in mind, I'm not doing cross country (or even regional) trips with this set up. Our Foretravel pusher pulls the trailer to the farther locations. This will just be for making day trips to local tracks.
My plan right now is to get the trailer over to the scales to confirm tongue weight. If below 650lbs, I won't worry about it. If over 675, then I'll think about how I could move contents around. Then I'll post pics of the GL pulling a 28' car trailer...
On the weight distribution bars, I still plan to use them (not heavily cranked up) to eliminate the 'hobby horse' fore/aft movement when going over the 'whoops'. The suspension will get a little workout.
MBWorld Fanatic!
Joined: May 2007
Posts: 2,244
Likes: 1
From: Scottsdale, AZ
2004 RX330, 2008 Scion xB, 2001 Honda Insight Hybrid, 2010 Toyot Prius v ATP
Is it true that the #$%@ thing is mounted to the $%$##^# unibody? Not the frame? Good greif! I need to look at this. I'm glad I've only towed basically "nothing" in a small open trailer. As for weight redistribution, that's the pilot in me - can't help it.
Junior Member
Joined: Jan 2010
Posts: 54
Likes: 0
From: SW Washington
07 GL320 CDI
Its even near the limit for the class 5 on the truck.The day before, I had the WD hitch apart and set it up for the GL. I started to set the trailer down on the hitch to check level and GL and the rear end kept sinking and sinking, so I stopped and lifted the weight back off. I figured then it was too heavy, but didn't know how much until yesterday.
