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Old 10-16-2012, 10:49 AM   #113
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[QUOTE=MaxTow;1215832]
Having gone through the search for a TV, I have found that the tow capacity is not that useful a number. It is almost always the payload that limits the operation of the vehicle. So having a standardized test methodology will certainly aid the public (and salesmen) in comparing vehicles.

So maybe I'll modify my original statement. The tow rating of a vehicle might certainly be set by the marketing department - but (if published) the GCWR is the real number of interest. Subtract the GVWR from the GCWR and this (in my opinion) is the true tow capacity.

[
The X5 has limited payload capability when coupled with heavy towing. At maximum load, assuming optimal distribution, there not much headroom before one exceeds the GAWR.

Maxtow

The trailer capacity is a worthless specification and also results in a lot of folks towing way over the limit for the payload and GVWR of the truck. It is used because it is simple and allows salesman and consumers to justify the towing of the large trailer that they really want. For example, my Tundra has a trailer tow capacity of about 10,000 lbs. When the consumer goes shopping for a trailer, he will consider all trailers that weigh less than 10,000 lbs. In reality, my 4,700 lb Tradewind results in my loaded Tundra actually being 60 lbs over the vehicle GVWR (6,900 lbs).

If there is going to be a towing spec. I agree that it should be the GCWR minus the truck GVWR. This still does not improve things much as it results in a trailer tow rating for my Tundra of about 9,100 lbs (16,000- 6,900).

The real limiting factor is the TV GVWR and the RAWR (rear axle weight rating). Payload needs to be calculated by taking a trip to the CAT scale and weighing the truck with all normal stuff in the TV with a full tank of gas. Then subtract this weight from the GVWR.

Dan
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Old 10-16-2012, 11:50 AM   #114
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[QUOTE=TouringDan;1216015]
Quote:
Originally Posted by MaxTow View Post
Having gone through the search for a TV, I have found that the tow capacity is not that useful a number. It is almost always the payload that limits the operation of the vehicle. So having a standardized test methodology will certainly aid the public (and salesmen) in comparing vehicles.

So maybe I'll modify my original statement. The tow rating of a vehicle might certainly be set by the marketing department - but (if published) the GCWR is the real number of interest. Subtract the GVWR from the GCWR and this (in my opinion) is the true tow capacity.

[
The X5 has limited payload capability when coupled with heavy towing. At maximum load, assuming optimal distribution, there not much headroom before one exceeds the GAWR.

Maxtow

The trailer capacity is a worthless specification and also results in a lot of folks towing way over the limit for the payload and GVWR of the truck. It is used because it is simple and allows salesman and consumers to justify the towing of the large trailer that they really want. For example, my Tundra has a trailer tow capacity of about 10,000 lbs. When the consumer goes shopping for a trailer, he will consider all trailers that weigh less than 10,000 lbs. In reality, my 4,700 lb Tradewind results in my loaded Tundra actually being 60 lbs over the vehicle GVWR (6,900 lbs).

If there is going to be a towing spec. I agree that it should be the GCWR minus the truck GVWR. This still does not improve things much as it results in a trailer tow rating for my Tundra of about 9,100 lbs (16,000- 6,900).

The real limiting factor is the TV GVWR and the RAWR (rear axle weight rating). Payload needs to be calculated by taking a trip to the CAT scale and weighing the truck with all normal stuff in the TV with a full tank of gas. Then subtract this weight from the GVWR.

Dan
I completely agree that it's not a one-number solution to determine what you can pull. The auto manufacturers don't make it easy and car and RV salesman don't either. Either because they don't really understand, but also, it's not in their best interest financially.

GCWR - GVWR gives a more realistic upper limit. But as you indicate, it's still possible to overload the TV and a given axle. Individual axle overload can be controlled with a WD hitch in the case of a TT. Trips to the CAT scales are required to verify and dial it in.
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Old 02-20-2013, 11:05 PM   #115
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Something I hadn't realized...the note about not using weight distribution hitches is in the OEM hitch documentation, not the owners manual of the car. If the warning bothers you (as it did me for awhile), simply purchase an aftermarket hitch that does support weight distribution
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Old 02-21-2013, 08:02 AM   #116
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These last three postings are spot on ... information that many do not want to consider...for the safety of the driver/passenger in the TV and all the other vehicles in their vicinity. We are not pulling our AS with a truck because it is our preferred method of tow; rather, it is the method that keeps us under published limits ... just as I didn't fly an airplane which exceeded its operating limits.
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Old 04-04-2016, 04:41 PM   #117
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Wow, OK I've read through 9 pages on this subject as I've recently acquired a '12 BMW X5 Diesel..it's got a dealer installed hitch and wiring and it seems fantastic so far with our '59 Overlander 26'. The trailer weighs about 4,000 lbs loaded. The tongue weight, with full propane tanks, is about 325 lbs max. I can't even feel it back there, and all indications seem to point to letting the X5's electronics and stability control do the "anti swaying" on it's own. Am I on track here?
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Old 04-04-2016, 05:14 PM   #118
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I can't even feel it back there, and all indications seem to point to letting the X5's electronics and stability control do the "anti swaying" on it's own. Am I on track here?
Not in my opinion. If you have a light trailer, and a reasonable tongue weight for the trailer weight, you may be okay without trailer sway control in the coupling. I would use it though, myself.

The vehicle trailer stability control system is not a sway prevention, it is a last resort recovery when the vehicle senses excessive sway. It would be like not wearing a seatbelt because you have airbags, or driving over a nail belt because you have run flat tires. You may get away with it, but it is a supplementary system, not sway prevention or control. I have had the BMW trailer stability control on two vehicles that I towed with, and I never got the TSC to come on, including when towing a large box trailer in the snow. It was nice that it was there in case there was excessive trailer sway, but I never got to that point.

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Old 04-04-2016, 05:42 PM   #119
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"The trailer weighs about 4,000 lbs loaded. The tongue weight, with full propane tanks, is about 325 lbs max."

Too light of tongue weight for stable towing as recommended by Airstream. You need no less than 10% or 400 lbs if loaded to 4,000 lbs.

A simple and effective w.d. hitch such as Eaz-Lift with an adjustable sway control bar attached to the hitch and trailer tongue is good anti-sway insurance, and allows you to restore any weight removed from your steering axle to ensure full control.
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Old 04-05-2016, 10:33 AM   #120
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Quote:
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"The trailer weighs about 4,000 lbs loaded. The tongue weight, with full propane tanks, is about 325 lbs max."

Too light of tongue weight for stable towing as recommended by Airstream. You need no less than 10% or 400 lbs if loaded to 4,000 lbs.

A simple and effective w.d. hitch such as Eaz-Lift with an adjustable sway control bar attached to the hitch and trailer tongue is good anti-sway insurance, and allows you to restore any weight removed from your steering axle to ensure full control.
Hmm..yeah that's a good point. It makes me wonder, though, why the original factory spec was 3850 lbs total and the tongue weight was 250 lbs, if I remember correctly?

Maybe they evaluated this over the last 50-60 years, lol
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Old 04-05-2016, 12:54 PM   #121
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Towing stability analysis uses trailer weight, tongue weight and also speed in the consideration. Less tongue weight would require a slower travel speed. Might just be possible that folks towed at 45 or 50 mph at the time your trailer was built. Pat
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Old 04-05-2016, 12:58 PM   #122
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I agree with PKI. Being from Europe, I am ok with towing at 50 mph, which is 80 km/h, a common speed limit when towing. This is one of the reasons, why European trailers are lighter on tongue.
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Old 04-05-2016, 12:59 PM   #123
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No kidding, these days on the interstate at 65 mph or so everything on the road passes us. Even a four-wheeler driving alongside in the ditch one time.

This is a generation in a hurry.
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Old 04-06-2016, 12:17 PM   #124
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Well, we have ripped out our black tank and toilet (in lieu of going the natural porta potty route) from the trailer's back end, and are planning a fresh water tank to go in under the front end shelf (behind the new pullout couch) so this weight distribution might just work perfectly soon
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Old 04-06-2016, 01:32 PM   #125
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Hmm..yeah that's a good point. It makes me wonder, though, why the original factory spec was 3850 lbs total and the tongue weight was 250 lbs, if I remember correctly?
Apart from the towing speed issue, which is very relevant, there is another factor that hasn't been raised. It isn't just about the weight distribution front/rear (resulting in xx tongue weight) but about the distribution of significant masses relative to the distance to the axles. Two otherwise identical trailers at 4000 lbs, with 10% tongue weight, and the same overall length and axle position, just as an example) can have very different towing stability characteristics due to that weight distribution. If trailer A has the weight concentrated more over the axles, it will have a lower moment of inertia than trailer B, which could have significant weights at each end of the trailer (but the same resulting tongue weight). For a quick demonstration of the effects of moment of inertia, go on a playground merry go round, spin up to speed, and then alternately lean in to the centre and lean out. Your rotational speed will change. Or watch a figure skater tuck their arms in to their body to spin faster. This rotational inertia is a prime contributor to sway, as there is a pendulum at work.

Euro trailers typically tow at lower speeds, and have less tongue weight, but they also try to have all of the mass concentrated over the axles. Our 10-15% tongue weight rule is for typical North American layouts, which often have significant weights at the extremities, due to valuing floor plan convenience over towing performance.

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Old 04-13-2016, 10:20 PM   #126
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For what it's worth, my wife and I spent four months last year touring the national parks in our 2014 23FB with 2013 X5 TV, and it could not have gone better. The X5 (gas) was able to handle anything! Boy did we get weird looks from those with 3/4 ton pickups though. Peppered with questions at every gas stop, which got a little old.

We just traded up to a new lease on a 2016 X5d turbodiesel, and the dealer installed a new-fangled hitch (Invisihitch?) instead of the previous standard 2" square receiver. It's rated to 6,000#, with 600# tongue weight. However, the ball mount does not accommodate weight distribution system (WDS/sway control). Looking at an adapter plate that turns it into a standard 2" receiver so we can use the old ball mount and WDS ball.

New and old ball mounts:
https://www.dropbox.com/s/xpjx1q3w5f...Hitch.JPG?dl=0

Proposed adapter plate:
http://www.reese-hitches.com/product...r_Tube,2201172

Tried towing without WDS once and it was unstable at highway speeds.

So, to all those who want to tow with German engineering, I say go for it. Once I figure out the ball mount adapter issue with the new X5 hitch I'll post an update.
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