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Marty P View Drop Down
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Direct Link To This Post Topic: tow vehicle question
    Posted: 15 Jun 2019 at 10:10am
I am loking at a 190, but the model doesn't matter much since weights are close. i have a Mercedes Metris which most people never heard of. It is like a small Sprinter, bigger than a minivan and smaller than a full size van. Anyhow, it is rated for 5000.00 pounds tow capacity, and that should be adequate, I believe, but it is a four cylinder, pretty peppy and decent efficiency. I wonder if anyone has any thoughts on whether towing would be difficult or not with this setup. Appreciate any thoughts, and like this forum. Good resource.
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podwerkz View Drop Down
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Direct Link To This Post Posted: 15 Jun 2019 at 10:36am
I would NOT recommend this....a four cylinder engine and no tow-haul mode as far as I know. Is it front or rear wheel drive? 

Fully wet and loaded with all your gear and supplies and provisions, an r-pod can get close to 3500 pounds in some situations, and then you will also probably have some gear loaded in the van.

Possible 'tail wagging the dog' situation.

I dont see that small engine being happy towing the r-pod up a steep mountain grade. 
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Direct Link To This Post Posted: 15 Jun 2019 at 11:01am
I had to look up the Metris but after doing so I’m not going to jump to the conclusion that it won’t tow a 190 just because it’s a 4 cylinder. The Metris has a GCVWR of over 11000 lbs and a cargo capacity of 1800 lbs. Engine peak torque is 258 ft lbs, which is right there with the v6s if not higher. And the final drive ratio and trans gear ratios are similar to my Highlander. It’s rwd with a 126 inch wheelbase which is good as long as you’re not planning off road adventures.

So, assuming that you’re not simultaneously planning on loading the van heavily while towing it will tow, but with 208 hp the turbo 4 cylinder will be busy and it won’t tow fast. Whether that is acceptable or not is a matter of personal opinion. Not too many years ago that hp to weight ratio would have been considered rocket like, now not so much. It’s still better than most if not all class A rvs though.

One thing to check for would be whether it’s receiver hitch can take a weight distribution hitch, which you’ll probably want,
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Direct Link To This Post Posted: 15 Jun 2019 at 5:07pm
Is it the larger cargo version of the Metris? I ask because that one has 135" wheelbase, which would be better. I'm going along with offgrid on this one. I'm not going to say not recommended, but it looks better than many other tow vehicles that I've seen. Do not think of a turbo-4 like a normally aspirated 4.
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Direct Link To This Post Posted: 15 Jun 2019 at 9:48pm
I did a little digging also and the Metris rating for about 5000 pounds is limited to 12% grades (which is relatively steep) at up to elevations of about 3000 feet. 

Hmmm...it's possible I suppose, to find long grades of 12% at sea level, but you really gotta hunt for them. More likely they will be at much higher elevations with a noticeable drop in engine output.

There is a warning that the speeds while towing should not exceed 100 km/h, about 60 mph. This might just be a CYA type of warning.

They also limit the 'power supply' to the trailer at 240 watts (about 20 amps, more or less)...and there is a warning that the 'power supply' is not to be used for charging a trailer battery. 

They also note that there is no protection on that charge line for a starter battery discharge situation.

The Metris is listed as having an 18.5 gallon fuel tank, which will limit the towing range. Towing travel trailers typically reduces any vehicle's mpg to the 10-15 mpg range, assuming mostly flat terrain and no headwinds.

I'm sure the Metris is a fine vehicle, but I personally believe it will be out of it's 'comfort zone' pulling an r-pod with all the stuff we normally add for camping, unless the travel plans don't include steep mountain grades.


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Direct Link To This Post Posted: 16 Jun 2019 at 12:44pm
Originally posted by podwerkz

I did a little digging also and the Metris rating for about 5000 pounds is limited to 12% grades (which is relatively steep) at up to elevations of about 3000 feet. 


That 12% figure bothers me so I downloaded a Metris users manual to look at it. I couldn't find it in there, where did you see it?

The reason it bothers me is that the ability to climb a grade is going to be limited by the GCVW not the trailer weight. I would agree that loading a Metris and trailer to the GCVWR (11,600 lbs) and then climbing mountains would not be a good idea with that little engine.  But it should be easy enough to keep the actual GCVW down to something in the 9000 lb range which would give about a 25% improvement in hill climbing ability.  

The Metris alternator is rated at 190A which is quite good so I think it must be something else that is limiting the current through that connector to 20A, probably the conductor/fuse. Just running a separate 30A circuit from the Metris batter to the 7 pin connector (like all the rest of us do who don't have a prewired connector) would probably solve that.

If you look on the Metris forum there are folks who tow 4000+ lb trailers (including in the mountain west) with satisfactory results. The main criticism seems to be low hitch height. That forum would be good to be on to get answers from folks already using their vans for towing.  

I did find a spec that the Metris receiver can take a weight distribution hitch, and has a max of 500 lbs tongue weight (with or without wd).  Its very easy to exceed 500lbs tongue weight on a 190 so that should be considered. 

The other question is, does the Metris already have the tow package installed? There are multiple frustrated folks on the Metris forum trying to get that added aftermarket. 


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Direct Link To This Post Posted: 16 Jun 2019 at 1:09pm
https://moba.i.daimler.com/baix/trucks/vs20/en_GB/index.html#../../../trucks/vs20/en_GB/manual/subchapter_17_125.shtml:ID_58ae2522f5ca4873351f19157ec3b00d


If this link only gets you close, click Technical Data, then Vehicle Data, scroll to the bottom.

It's in metric values, but of course, 12% Imperial is 12% Metric.

Tongue

Also, here is a source for towing information with the Metris at higher altitudes:


I'm sure people are doing it...but I would not...having spent that much money on the van, only to thrash the little engine near maximum RPM trying to climb up long mountain grades. 

If the plans are to keep the rig mainly on flat, non-challenging terrain, then I won't make a lot of noise about it. 
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Direct Link To This Post Posted: 16 Jun 2019 at 3:04pm
OK, I see. You're looking at the GB (Great Britain) manual. That's why all the numbers are different than the US specs and are presented in metric. Also, there must be some kind of gradient climbing/desending spec in the GB towing certification process that doesn't exist in the US.  Here's the US manual. 


None of that shows up in this version. There's definitely something different in Britain because the same spec section in that manual calls out a "permissible max nose weight"  of 100kg which is only 220 lbs, and we know that the US tongue weight is listed at 500 lbs.

I think one thing that's going on in the GB version is that one of the specs is probably for climbing and one is for descending. Probably they want to limit climbing by GCWR and descending by trailer weight, with different descent numbers for braked and unbraked trailers. That would at least make logical sense. But I'm no expert of European towing specs and don't ever want to be. Disapprove

Assuming the British GCVW numbers are for climbing, a 4800 kg GCVWR is about 10,600 lbs and the 5700kg is an astronomical 12,600 lbs, more than the 11,600 lbs we see in US specs.  I wouldn't load things anywhere near either of those numbers if it was me, especially in the mountains.

Nor would I tow a 5000 lb trailer in the mountains with that vehicle, or with my Highlander either for that matter. The GVWR for a 190 is about 3800 lbs anyhow so even a fully loaded one isn't anywhere near 5000 lbs. 

Bottom line for towing, as always, know what your rig and each of its axles weighs, and the trailer tongue weighs, and stay well below the max ratings for each of those numbers, especially in the mountains. Use a good wdh and sway control, and drive carefully and keep your speeds down. 

And for sure, the little turbocharged 2 liter 4 cylinder engine is going to be working hard, no doubt about it. Its a personal decision whether or not you are comfortable with that. Just don't expect your fuel economy to be good just because its good running around town in a lightly loaded van. LOL



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Direct Link To This Post Posted: 16 Jun 2019 at 3:17pm
Originally posted by offgrid

OK, I see. You're looking at the GB (Great Britain) manual. That's why all the numbers are different than the US specs and are presented in metric. Also, there must be some kind of gradient climbing/desending spec in the GB towing certification process that doesn't exist in the US.  Here's the US manual.


Well that's where I had to go to 'dig up' the information as I mentioned earlier. And yes, I accessed the US version also. 

BTW, there IS a USA standard for towing, called J2807. If Mercedes publishes a towing rating in the USA that complies with the SAE J2807 standards, then the 12% gradient, horsepower, torque, handling, steering, cooling, gear ratios, brakes, etc are already figured in to the rating. I dont know if Mercedes complies with that rating or pulls the 5000lb rating out of thin German air,...but either way, it is what we have to go by. My Nissan Titan XD is rated using J2807, so I'm confident in it's towing capabilities.

https://fifthwheelst.com/SAE-J2807-Tow-Tests.html

http://www.rv-project.com/resources/j2807.php

(note the typo on that last page: 12% grade is 12 feet change in 100 feet, not 1000 feet.)

And of course European specs can be different, just as towing laws in the US vary from state to state for RVs...that's a whole 'nother kettle of fish.

But the motor/transmission combo is the same, as far as I know, although it might be rated differently due to emissions or conversions between hp and kw terminology.

What we dont know is: can the Metris tow 5000 pounds with a passing score using J2807 metrics? (see what I did there?) If it can, great, but I suspect it would be rated lower, maybe 3000 pounds, under J2807.

So it comes down to choice, I suppose. My choice would be to find a lighter, smaller trailer for the Metris, or replace the Metris with a larger SUV or pickup more suitable for the job.




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Direct Link To This Post Posted: 16 Jun 2019 at 6:54pm
Yes, I'm aware of J2807.

The thing that makes me more comfortable with the Metris is the high vehicle gross weight and the high GCVWR. There is around 2000 lb available there to apply toward the trailer weight as long as the van itself is kept reasonably light when towing. So even if the vehicle doesn't meet the spec at the 11,600lb GCVWR, at a more reasonable 9000 or so lbs it probably does OK.  

In the end, as you say, its a personal choice. If it was me and I already had a Metris in my driveway that was working well for my other needs, I'd give it a try and see how it performed before making a change. 
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