Does anyone have experience towing a heavy (7000+ lb) trailer with a GL320? I'm attracted by the fuel economy and range of the GL320, but it's a big step down in power from my Cayenne Turbo. I don't expect it to be zippy, but need it to tow the trailer up a mountain at a reasonable speed. Unfortunately, I can't wait for MB to get around to releasing the GL420, which would be perfect for my needs.

The Cayenne is great for power, but you need to keep a really close eye on the gas gauge when towing. I had to drop the trailer once and drive ahead for fuel near Nowhere, CO.

 

It is awesome...

Cayenne: 273 lb-ft Torque @ 3000 rpm

Cayenne S: 369 lb-ft Torque @ 3500 rpm

GL320 CDI : 398 lb-ft torque @ 1400 - 2800 rpm

 

I've gotten gas there before, too. The temperature was about 1. Kelvin.

Seriously, it sounds like the factory hitch and brain do wonders for towing stability, and a couple of people here have noted they don't even notice the trailer. How heavy are you planning on towing?

 

I will be wiring up my Prodigy Trailer Brake Controller this weekend and probably doing a few test tows next weekend. I am towing a 5000 Lb Jeep on a 1500 lb trailer so at 6500 it will be close to 7K.

 

I'll be right at the limit (7500 lb) on towing. My travel trailer is just over 6800 lb empty, so I always had to be careful to stay under the Cayenne Turbo's 7700 lb limit. I'll have to be even more careful with the GL.

 

The diesel is great for towing. The low end torque works wonders and the ESP for the trailer is a nice feature as well. I wouldnt worry too much if you're right at the 7500lb limit, but if you're planning on going over, why not just buy a F250 or Duramax truck?

 

Being close to the limit means not that the car can't tow it but that you're probably up against the brakes' limits. The suggestion of something more beefy for towing might be a good one for a travel trailer that's already only going to allow 700lbs loaded! (Sometimes being a pilot is useful for all that hard math.)

Ford are making a common-rail diesel for 2008, and thier F-550 (I think it was) will tow a zip code. (It really was some ridiculous numbers.)

 

There's no question a big diesel truck would make a better tow vehicle, but I've really been spoiled by the Cayenne Turbo. In addition to being a great tow vehicle, it's a pleasure to drive when you're not towing. I test drove the GL (not towing), and I'm sure it would make a very competent and safe tow vehicle. Unfortunately, the wife is very spoiled, and she declared the GL underpowered. We'll be keeping the Turbo a while longer despite its drinking problem (12 mpg city).

I'm expecting the GL420 will fit us better, and hoping they just offer the engine as an upgrade without all the mandatory options like on the GL550. The oversized summer-only wheels and tires on the Cayenne kept us from going some places in an otherwise excellent off-road vehicle. I hope Mercedes doesn't make the same mistake with the GL420. They should leave the oversized wheels as an option for those who want them.

 

when is the GL420 expected? I've been towing with my 03 ML500, and it's a breeze, but the rear gets too low to the ground for my taste. The loaded trailer is around 5,000lbs.
Is it easy to install a brake controller?