R-Class (W251) Produced 2006-2013: R320CDI, R350, R420CDI, R500

Who says a minivan can't tow...

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Mar 21, 2022 | 01:42 PM
  #1  
Tsumi's Avatar
Thread Starter
Super Member
5 Year Member
 
Joined: Nov 2017
Posts: 558
Likes: 114
From: San Francisco Bay Area
2006 R500
Who says a minivan can't tow...

... well, a minivan with the underpinnings of a Mercedes SUV.



Just brought this beauty home; 5.5 hours, including mountain passes, averaged 65-70 mph. Engine braking automatically kicks in when braking, which made things effortless on downhill sections. Probably weighed around 5500 lbs. Super stable, the only sign of trailer sway came from 20+ mph crosswinds. Averaged just over 13 mpg when cruising on flat land.

2006 R500 with airmatic suspension, using a modified OEM hitch. Two complaints: braking isn't as good as I would like as this one has the 330 mm front rotors with the 330 mm solid rear rotors, and a transmission issue during hill climbs.

For the braking, I am planning to upgrade to R63/ML63 brakes, which should be more than sufficient to stop this. Even the 350 or 375 mm front rotors with the 330 mm vented rears from the GL class would be much better, but I figured I may as well go all the way.

As for the transmission issue, it refuses to downshift on long hill climbs, even with the gas pushed all the way down, and the manual button shift doesn't work either. I have to lock it into an appropriate gear before the climb starts. Anyone know anything about this? I presume it is the transmission overheating. I plan on getting the Weistec transmission pan to help with this.
Reply
Old Mar 22, 2022 | 10:55 AM
  #2  
B34chBum's Avatar
Senior Member
5 Year Member
Liked
 
Joined: Mar 2017
Posts: 258
Likes: 50
R320, Astro, JSW, ST4
Yes, really nice tow vehicle - even with a Curt hitch and 'Sport' package (rear air ride only).
That is, when everything is working right

Just curious, do you have/have you tried the Sport setting on the transmission?
Reply
Old Mar 22, 2022 | 11:08 AM
  #3  
Tsumi's Avatar
Thread Starter
Super Member
5 Year Member
 
Joined: Nov 2017
Posts: 558
Likes: 114
From: San Francisco Bay Area
2006 R500
I leave it in sport mode all the time.

I have found a couple of X164 threads that describe this behavior, so I'm pretty sure it has to do with transmission temps. It locks it into a gear until it cools down.
Reply
Old Mar 23, 2022 | 03:59 PM
  #4  
Tsumi's Avatar
Thread Starter
Super Member
5 Year Member
 
Joined: Nov 2017
Posts: 558
Likes: 114
From: San Francisco Bay Area
2006 R500
So I took a look at my radiator setup and it does not have the additional transmission cooler. Looks like that will be something I will be retrofitting in the near future. If that's still not enough to help, I'll be getting the Weistec pan with an additional cooler.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 01:29 PM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE