Mercedes ML350 Bluetec - How big a TT can I tow?

[Proteus]

New to this and need some advice. I have an ML350BTC as a tow vehicle. Plenty of power (455 ftlbs), and it has a 7200lb tow rating. I'm looking for a lightweight 25-28ft travel trailer with bunks (something like a surveyor sport, or passport). There is a huge difference in weight and construction..the ones I'm looking at come in right at 5000-5200lbs (delivered weight, from door sticker)

Question is, I've visited a number of RV dealers so far that seem to think you need you need a traditional truck to tow (although one changes his mind when I pointed out this was basically a fancy Jeep Grand Cherokee)

GVWR is 6504, RAWR - 3638, FAWR 3197, curb weight 5109.
This leaves me with a payload of #1395 (more than a "half ton" in truck speak). Tires are rated over 2100lbs each, so no issues there.
My hitch rating is low at 575lbs, since European standard is 8% on the hitch, not 15% like here. From what I understand, a good WD system will take care of that (locally, equalizer "four points" seems to be popular). Per the dealer, the MB has trailer towing software that automatically detects and corrects for sway.

So question is this: Can I safely tow something like:
Keystone Passport 2650BH (4950 dry, 470 hitch),
Coachman Captiva 270RS (4600 dry, 740 hitch, the WD should help here?)
or even a Surveyor cadet SC-280(4700, 504 hitch).

I know in Europe, people tow large boats and caravans with these, and even here in the US, the Airstream crowd tow the heavy 25-28ft models (and per youtube, apparently even the 7500lb 30fter!). At the same time though, there seems to be some great difference of opinion out there.

[sky_free]

Road Ruler wrote:

blt2ski wrote:
If a pickup had/has the same features the MB suv has from an anti sway etc setup, then they would be every bit as equal as the European SUV's! Marty

IMHO this is the "Quote of the day"

Will we ever see the day the average pickup would be designed with a high performance suspension, handling, tire pkg system like the high end Euro cruisers??

I believe the main hold back is the frames. They are too flexy to effectively react to the demands of IRS. Another reason is cost. There is so much profit in the pickups the way they are why make them more costly to produce as most folks driving them seem to be satisfied.

Sure there is a limit to what a Euro SUV is going to pull. The big dually pickups have the edge there.

Light duty 1/2 ton trucks are heading in that direction, but HD trucks can't for many reasons. Tires are the biggest one. Try putting E-rated 10-ply tires on your SUV and see how it handles. The tires on an HD truck are made to haul a heavy load, as is the huge heavy frame, large springs, and massive transmission (mine holds 18.5 quarts of oil). It's designed for a purpose and these components are going to make the handling and fuel economy worse than a luxury SUV. That's never going to change due to pure physics. Most modern trucks have anti-sway BTW.

[Road_Ruler]

blt2ski wrote:
If a pickup had/has the same features the MB suv has from an anti sway etc setup, then they would be every bit as equal as the European SUV's! Marty

IMHO this is the "Quote of the day"

Will we ever see the day the average pickup would be designed with a high performance suspension, handling, tire pkg system like the high end Euro cruisers??

I believe the main hold back is the frames. They are too flexy to effectively react to the demands of IRS. Another reason is cost. There is so much profit in the pickups the way they are why make them more costly to produce as most folks driving them seem to be satisfied.

Sure there is a limit to what a Euro SUV is going to pull. The big dually pickups have the edge there.

[NinerBikes]

25 to mph is a personal limit that I set. I am not a young spring chicken any more these days with my reaction times or eyesight. I like and enjoy uneventful drives to where I am going camping. I like taking my time. I like high MPG while towing. I'm Dutch, and I am almost as cheap as a Scotsman.

Just my belief that by driving slower and obeying the speed limit (oh and BTW, for all of you out of staters that visit here in CA, some folks need to read the speed limit road signs on Interstates, the speed limit is 55 for all trucks, including SUV's, with trailers, on Interstates, including I-10), it increases my reaction time.

While my Touareg is capable of such maneuvers, cones belong on a track or a race course, and are a poor substitution for the reality of trailering in a state like California, with 40 million people in the state, many of which don't read English, or perhaps don't belong here, or perhaps are stuck with double digit IQ's on our public roads, in uninsured vehicles with no drivers license. Trailering, so far, in the west, in any other state, is a cake walk, compared to trailering anywhere through Southern California's Metropolis mess. Sad that I live here, weather is great, the people, not so much anymore.

As to the sway, it is inconsistent, and in my mileage, seems to be a combination of factors, all at once. Big Buses, going very fast 80 to 85 mph, think Van Hool, with huge frontal areas and a big bow wave, in Utah, where the speed limit is 80 and folks do 10 to 15 over that, on a whim, with cross winds out of the NW, with the driver straying closer to the right of their lane, seem to be the worst. Big rig trucks that are sleepovers with sloped noses are a non issue.

I can tell you, professional big rig drivers are much better about staying left in their lane when passing travel trailers, part time motor home drivers seem to be clueless as to the affect of the bow of their wind waves on travel trailers, doubt they were schooled on driving them, or they are not very observant.

I have driven both with and without the WDH, if my front end didn't come up 1" and rear end sag 1 3/4", I'd do without the WDH, the Touareg drives for some reason, much better without it, the trailer is free to react to the cross winds without being all tightened up and pushing the front end into the Bots Dots.

The Touareg, from what I have been told, has all the fancy anti sway software, brain power, brakes, and X,Y,Z yaw sensors built in to it... it comes off the same production line as the Cayenne and Audi Q7... it's just shorted on all the deluxe bells and whistle features on the interior, in the Sport model. For $40,000 for a diesel, at year end sale prices, it was hard to say no.


Basically, I really just don't enjoy driving in stiff cross winds. I get conservative, and get off the road then, I've seen too many blown over big rigs, 5th wheels, TT's and motorhomes on highway 395 in Eastern California on my way from L.A. to Mammoth Mtn or Bridgeport... way, way, way too many.

As always... YMMV.... these are my observations.

PS, the aerodynamics of a box, and an AirStream, is not a fair comparison... the Airstream is 4x to 6x the price or more of what I paid for my Palomino. The cD of an Airstream is much lower, and has much less flat surface for a bow wave to have an effect. When I bought the 21 footer, for $13,000, brand new, near MI, I got what I paid for, I don't have the right to expect much more from it when towing. If it ever got broken in to, or stolen, I wouldn't worry too much about insurance or the loss. An Airstream is another story... for that kind of money, I'd be looking into a 5th wheel instead.

[blt2ski]

If a pickup had/has the same features the MB suv has from an anti sway etc setup, then they would be every bit as equal as the European SUV's! Until that time comes, then for smaller trailers, these SUV's are killer. For larger trailers, one is stuck with the heavier duty light duty trucks.

I would also agree that ninerbikes has a setup issue with the trailer. He should not have had any issues with those side winds, unless it is his issue, not the rig as a whole. I've driven in 30-50 mph sidewinds. Yeah, a bit interesting, I did slow a bit depending upon the winds, how they were hitting etc, but nothing to say I felt out of control per say. Altho it is a bit interesting when one gets moved a whole lane buy a side gust, as I did going across I205 from Portland to Vancouver with what was probably a 60-80 mph gust. I was not the only rig that moved 1/2 to a full lane either!

Marty

[Road_Ruler]

Proteus wrote:

I certainly understand those who say that trucks are better for towing and hauling, .but they're no fun at all to drive in the daily commute, or for a family.

Pickups will get you by but if you want the ultimate in performance and control you will not get anything better than a properly set up Mercedes, BMW, Porsche, or T-reg in the SUV format. Check out the way the Porsche man handles the out of control TT. Advance to the 130 point in the vid below.

http://smg.photobucket.com/user/CF105/media/ASPerfVideo.mp4.html

[Proteus]

I agree. I had very little trouble with crosswinds in the ML. Maybe the hitch wasn't setup correctly?
I certainly understand those who say that trucks are better for towing and hauling, .but they're no fun at all to drive in the daily commute, or for a family.

[Road_Ruler]

NinerBikes wrote:


My TV is a 2013 VW Touareg TDI Sport. 240 HP, 406 ft lbs. Tongue weight 300 dry on a 21 foot 7.5 ft wide TT that weighs in at 3700 dry. Bought the Touareg with factory hitch, 7700 lbs, limited by the unibody construction on all engines. Tongue weight is 770 lbs, max.

With propane, battery, etc, I run a 600# Equalizer Hitch. I probably have 300 to 400 lbs on board the trailer.

At this point, in 2 years, I have 16000 miles on it. I will not trailer if cross winds are much over 25 mph, I pull over. No equalizer hitch will help you in a cross wind if a big rig blows by you at 80 mph while you are doing 55... 21 foot of wind sail leaves you with sweaty hands and white knuckler moments, too much hinge effect at the trailer hitch point with the SUV having a short wheel base. Allows the trailer in a cross wind to have a lot of leverage at the pivot point, where the two vehicles are joined.

Out west, there is no way I'd go much over 21 to 23 or 24 feet, with a 5000 # Touareg, Cayenne, or Q7.

Trailer is a Palomino Gazelle G21.

3.0 Liter diesel at 55 -58 MPH and 8 speed transmission averages 16.5 to 19 MPG. I seem to manage to find some tailwinds most of the time from Los Angeles to Yellowstone.

I do slow down a bit going up the steeper grades in CA, NV, UT,ID and MT. Retired, no rush, don't believe in pushing my motor hard going up hill doing a lot of work. I try to keep fuel consumption at no more than 4 to 4.5 gals per hour of diesel fuel being burned when going up hill. Function of speedometer, and instantaneous MPG in the dash keeps me from running hot. Don't burn the fuel fast if you want the heat dissapaition spread over a longer time.

Ninerbikes.... You really need to get your rig set up optimally. You have one of the highest rated TV's money can buy yet you are struggling with it because it is set up so poorly. PS... my ride is a Fuel 98. Luv it.

[sky_free]

NinerBikes wrote:

Proteus wrote:
Thanks, just for an update on this, we decided to rent for a while, and took a Nash 25c (not ideal) from Seattle all the way to Yellowstone and Glacier. The trailer loaded was about 6200lbs, so within the 7200lb tow rating, and we used an equalizer 4 points wd hitch and prodigy bc. We did everything from broken roads, to long stretches on the plains with 40mph crosswinds, and did some nice long steep sections, including the continental divide.

So, this combo worked, but it wouldn't recommend it . The Nash rides high, isn't that aerodynamic and has a bouncier off-road suspension. The weight itself was fine..the diesel has plenty of torque (455) so pulling was never an issue, and was great for engine braking too. Going steep uphill on the long I-90 stretch over the divide, the little engine was working hard I had to slow to 50mph in sections (normally kept at 60-65). Trailer sway in crosswinds was noticeable, but the trailer mode in the AWD corrected everything nicely. Rain, thunderstorms, no problem, just slowed down some.
Oh, and I averaged about 13mpg towing (vs my normal 30 highway, not too shabby). I would NOT do this with a gas model. The diesel makes a huge difference. Note that the Jeep Grand Cherokee is basically the same thing. I have to say, was pretty funny seeing the occasional guy in pickup truck gasp as we passed them 🙂

Bottom line, I'd say a 4500-5000lb dry trailer is fine. I would make sure it has a proper (not bouncy leaf spring) suspension, and rides lower to the ground. It's a modern SUV and needs a modern trailer to go with. Airstream would also be great, but they're not family friendly (we need a bunkhouse.

My TV is a 2013 VW Touareg TDI Sport. 240 HP, 406 ft lbs. Tongue weight 300 dry on a 21 foot 7.5 ft wide TT that weighs in at 3700 dry. Bought the Touareg with factory hitch, 7700 lbs, limited by the unibody construction on all engines. Tongue weight is 770 lbs, max.

With propane, battery, etc, I run a 600# Equalizer Hitch. I probably have 300 to 400 lbs on board the trailer.

At this point, in 2 years, I have 16000 miles on it. I will not trailer if cross winds are much over 25 mph, I pull over. No equalizer hitch will help you in a cross wind if a big rig blows by you at 80 mph while you are doing 55... 21 foot of wind sail leaves you with sweaty hands and white knuckler moments, too much hinge effect at the trailer hitch point with the SUV having a short wheel base. Allows the trailer in a cross wind to have a lot of leverage at the pivot point, where the two vehicles are joined.

Out west, there is no way I'd go much over 21 to 23 or 24 feet, with a 5000 # Touareg, Cayenne, or Q7.

Trailer is a Palomino Gazelle G21.

3.0 Liter diesel at 55 -58 MPH and 8 speed transmission averages 16.5 to 19 MPG. I seem to manage to find some tailwinds most of the time from Los Angeles to Yellowstone.

I do slow down a bit going up the steeper grades in CA, NV, UT,ID and MT. Retired, no rush, don't believe in pushing my motor hard going up hill doing a lot of work. I try to keep fuel consumption at no more than 4 to 4.5 gals per hour of diesel fuel being burned when going up hill. Function of speedometer, and instantaneous MPG in the dash keeps me from running hot. Don't burn the fuel fast if you want the heat dissapaition spread over a longer time.

I wonder if your equalizer hitch is causing you problems with crosswinds? I was running almost the exact same trailer on the same Touareg with a cheap EAZ-lift 600 lb weight distributing hitch and friction sway bar. Towed for 2 seasons and never pulled over for crosswinds. One time I had an approx 50MPH crosswind for 150 miles on I-5 in February. The tumbleweeds were FLYING across the highway. I was more worried about hitting the huge tumbleweeds than sway. Not criticising your choice of hitch, but maybe something different will help you feel confident in winds?

[brulaz]

BenK wrote:

...
Marry that with variable displacement (cylinder deactivation) and the
MPG's will be very good running empty.
...

About 2/3 to 3/4 of our truck's mileage is towing a 7500-8000# TT with 64 sq ft of frontal area at ~62mph.

All this new gasser tech is wonderful. Love our EcoB with all the low end torque, and its HP is wonderful. But think that for mileage under load you need to go diesel.

[BenK]

If you were looking at a Touareg, then these also fit in that price range PLUS
has the MPG you desire

Price range, as long as you keep the number of bells and whistles down... :B


This is GM's new direct injection with cylinder deactivation (full
V8 down to V6 or V4). Don't know if GM offers this in their pickups...yet
GMs new 6.2 di seems to get great mpg



This is GM's small V8, but don't know if it has direct injection
2015 Suburban LT


Soon, there will be GDICI (Gasoline, direct injection, compression
ignition...no spark plugs), which will have very similar attributes
to diesel fueled

Marry that with variable displacement (cylinder deactivation) and the
MPG's will be very good running empty.

The reports to date also shows diesel like torque curves from start
to top end

Just have to wait...

[brulaz]

NinerBikes wrote:

...
My TV is a 2013 VW Touareg TDI Sport. 240 HP, 406 ft lbs. Tongue weight 300 dry on a 21 foot 7.5 ft wide TT that weighs in at 3700 dry. Bought the Touareg with factory hitch, 7700 lbs, limited by the unibody construction on all engines. Tongue weight is 770 lbs, max.

With propane, battery, etc, I run a 600# Equalizer Hitch. I probably have 300 to 400 lbs on board the trailer.

At this point, in 2 years, I have 16000 miles on it. I will not trailer if cross winds are much over 25 mph, I pull over. No equalizer hitch will help you in a cross wind if a big rig blows by you at 80 mph while you are doing 55... 21 foot of wind sail leaves you with sweaty hands and white knuckler moments, too much hinge effect at the trailer hitch point with the SUV having a short wheel base. Allows the trailer in a cross wind to have a lot of leverage at the pivot point, where the two vehicles are joined.

Out west, there is no way I'd go much over 21 to 23 or 24 feet, with a 5000 # Touareg, Cayenne, or Q7.

Trailer is a Palomino Gazelle G21.

3.0 Liter diesel at 55 -58 MPH and 8 speed transmission averages 16.5 to 19 MPG. I seem to manage to find some tailwinds most of the time from Los Angeles to Yellowstone.

I do slow down a bit going up the steeper grades in CA, NV, UT,ID and MT. Retired, no rush, don't believe in pushing my motor hard going up hill doing a lot of work. I try to keep fuel consumption at no more than 4 to 4.5 gals per hour of diesel fuel being burned when going up hill. Function of speedometer, and instantaneous MPG in the dash keeps me from running hot. Don't burn the fuel fast if you want the heat dissapaition spread over a longer time.

Thanks for that post. Very informative.
And your towing mileage #'s are just wonderful.

I looked long and hard at the Touareg when we had the old 4000# (56 sqft front wall) trailer.

But in the end went with the EcoB and only got 12mpgUS. Really wanted the bed of a pickup (and lower cost helped too). Now with the new 7500# trailer (64 sqft wall) and ~1100# tongue weight, the Touareg wouldn't have been enough anyway. But only getting 10 mpgUS now. 😞

Still looking for a truck with better mileage though ... will probably have to be a diesel of some sort. The gassers can get fair mileage unloaded (my EcoB gets 20mpgUS), but not so much when towing.

The bigger diesels in the HD trucks are a bit overkill for us but tempting if they weren't so expensive. I maybe could match the EcoB's unloaded mileage and improve the towing mileage by 25%.

The RAM EcoD has similar engine specs as the Touareg, but doesn't have the payload we need. Like the Touareg it's just too little truck for our new trailer.

IOW there's now diesels available in the HD and light duty truck categories. What I would like to see is a medium duty ("heavy half") truck with a diesel. Maybe the Nissan with a 5L Cummins? We'll see ...

[NinerBikes]

Proteus wrote:
Thanks, just for an update on this, we decided to rent for a while, and took a Nash 25c (not ideal) from Seattle all the way to Yellowstone and Glacier. The trailer loaded was about 6200lbs, so within the 7200lb tow rating, and we used an equalizer 4 points wd hitch and prodigy bc. We did everything from broken roads, to long stretches on the plains with 40mph crosswinds, and did some nice long steep sections, including the continental divide.

So, this combo worked, but it wouldn't recommend it . The Nash rides high, isn't that aerodynamic and has a bouncier off-road suspension. The weight itself was fine..the diesel has plenty of torque (455) so pulling was never an issue, and was great for engine braking too. Going steep uphill on the long I-90 stretch over the divide, the little engine was working hard I had to slow to 50mph in sections (normally kept at 60-65). Trailer sway in crosswinds was noticeable, but the trailer mode in the AWD corrected everything nicely. Rain, thunderstorms, no problem, just slowed down some.
Oh, and I averaged about 13mpg towing (vs my normal 30 highway, not too shabby). I would NOT do this with a gas model. The diesel makes a huge difference. Note that the Jeep Grand Cherokee is basically the same thing. I have to say, was pretty funny seeing the occasional guy in pickup truck gasp as we passed them 🙂

Bottom line, I'd say a 4500-5000lb dry trailer is fine. I would make sure it has a proper (not bouncy leaf spring) suspension, and rides lower to the ground. It's a modern SUV and needs a modern trailer to go with. Airstream would also be great, but they're not family friendly (we need a bunkhouse.

My TV is a 2013 VW Touareg TDI Sport. 240 HP, 406 ft lbs. Tongue weight 300 dry on a 21 foot 7.5 ft wide TT that weighs in at 3700 dry. Bought the Touareg with factory hitch, 7700 lbs, limited by the unibody construction on all engines. Tongue weight is 770 lbs, max.

With propane, battery, etc, I run a 600# Equalizer Hitch. I probably have 300 to 400 lbs on board the trailer.

At this point, in 2 years, I have 16000 miles on it. I will not trailer if cross winds are much over 25 mph, I pull over. No equalizer hitch will help you in a cross wind if a big rig blows by you at 80 mph while you are doing 55... 21 foot of wind sail leaves you with sweaty hands and white knuckler moments, too much hinge effect at the trailer hitch point with the SUV having a short wheel base. Allows the trailer in a cross wind to have a lot of leverage at the pivot point, where the two vehicles are joined.

Out west, there is no way I'd go much over 21 to 23 or 24 feet, with a 5000 # Touareg, Cayenne, or Q7.

Trailer is a Palomino Gazelle G21.

3.0 Liter diesel at 55 -58 MPH and 8 speed transmission averages 16.5 to 19 MPG. I seem to manage to find some tailwinds most of the time from Los Angeles to Yellowstone.

I do slow down a bit going up the steeper grades in CA, NV, UT,ID and MT. Retired, no rush, don't believe in pushing my motor hard going up hill doing a lot of work. I try to keep fuel consumption at no more than 4 to 4.5 gals per hour of diesel fuel being burned when going up hill. Function of speedometer, and instantaneous MPG in the dash keeps me from running hot. Don't burn the fuel fast if you want the heat dissapaition spread over a longer time.

[Road_Ruler]

The Mercedes with the right trailer and right connection system is creme de creme.

Bluetec Mercedes and 30' Airstream

[Proteus]

Well, I agree you have to be careful with hitch weight, but that can be adjusted to a certain extent with a good WD system. The equalizer 4 points did the job, but we had to crank it hard. Note that mercedes likes about 8-10% on the hitch, NOT 15% used by domestic trucks. I disagree this relegates you to ultra lights though, as long as your base hitch weight isn't too high to start with. The Nash 25c admittedly was right at the limit. We had to load it heavily towards the rear otherwise it was notably harder to drive,