BMW X5d and Weight Distributing Hitch

[MaxTow]

As has been mentioned on this thread already, one needs to decide if they are comfortable pushing the design ratings on a TV, or living within the specifications.

While I am not an automotive engineer, I am an electrical engineer. In the design of telecommunications equipment, we will push the specifications of components in certain areas, but this is generally a) in consultation with the manufacturer b) based on considerable direct experience and c) validated with significant testing.

Neither are generally available to the individual car buyer.

As such, I like to live within the design specifications as I feel the consequences of being wrong are too significant.

A few more thoughts (these are my options based on experience in a design engineering field) -

• There has been mention of tow ratings being marketing driven numbers rather than based on design specifications - I don't buy this. For a company like Ford and their F-150, there is simply too much at stake to release an under spec'd truck. Now I can guarantee there will be a group of conservative engineers at Ford who 'simply cannot believe the reckless specifications being published', but there will be a balance of conservative and more aggressive engineers and a balance will be achieved.
  
• Tow ratings and payload ratings are derived to keep the vehicle safe over the life of the vehicle and under dynamic load. Forces applied to a loaded vehicle at speed in tough conditions are considerably higher than the forces at rest. We don't know how much margin is built into the design - but living within the specs again gives me some comfort. I also want that margin as my vehicle ages and rust starts to set in. If you live in an area with no rust, or plan on trading your vehicle often this is much less of a concern.
  
• Work vehicle manufacturers will spend considerably more time testing their products under towing conditions as compared with Minivan or high end Sport utility manufacturers who have very few customers interested in this application. It's not money well spent for these manufacturer. This gives me more confidence in the design of the work truck to live up the rigors of towing.

Now back to the OP's questions of the suitability of a BMW X5. As in most vehicles, I don't look at the tow ratings, but at the payload as a starting point. The X5 (Canadian Spec) X5 35d has a maximum payload of 585kg (1290 lbs) If the intended application is pulling an Airstream with an 880lb tongue weight then this does not leave much for anything else inside the vehicle. If we allocate 350lbs for driver + passenger*, plus 50lbs for a hitch then we are at maximum payload. (plus watch any options, as they also eat into this payload specification)



The Mercedes SUVs look like a better choice as they have a higher payload rating. The GL350 has a payload specification of 725kg (1600lbs) which rivals most 1/2ton pick-ups.

*apologies to those folks that are considerably lighter...

[OrangeKid]

Originally Posted by MaxTow

[/LIST]

Now back to the OP's questions of the suitability of a BMW X5. As in most vehicles, I don't look at the tow ratings, but at the payload as a starting point. The X5 (Canadian Spec) X5 35d has a maximum payload of 585kg (1290 lbs) If the intended application is pulling an Airstream with an 880lb tongue weight then this does not leave much for anything else inside the vehicle. If we allocate 350lbs for driver + passenger*, plus 50lbs for a hitch then we are at maximum payload. (plus watch any options, as they also eat into this payload specification)



The Mercedes SUVs look like a better choice as they have a higher payload rating. The GL350 has a payload specification of 725kg (1600lbs) which rivals most 1/2ton pick-ups.

*apologies to those folks that are considerably lighter...

Where did you find the Mercedes payload spec? According to Consumer Reports the GL450 has a maximum load (different than payload spec?) of 1210 lbs and the GL320 (2009 model) has a maximum load 1155 lbs. I could not find a maximum load or payload spec listed on the Mercedes Benz site. I have checked many SUVs and most have a maximum load rating of between 1100 and 1400 lbs. According to the 2113 MB Owner's Manual the maximum tongue weight rating of the GL is 600 lbs.

[MrUKToad]

Maxtow,

Thanks for your very considered view on manufacturers' design ratings, the more input the better I think.

In terms of the means by which vehicle tow ratings are set then I'd again refer you back to the Truck Trend article, in which named figures from the manufacturers themselves say that it's more to do with marketing and competition. Indeed, the thrust of the article is to highlight the new SAE ratings system which is supposed to provide the market with proper and measurable methods of arriving at a tow rating, simply because tow ratings have been allowed to be set by marketing men and lost their true value.

Where I do agree with you is that certain vehicles, pick-ups especially, are tested in towing situations, quite often to the point of breaking them - it's the market they serve and as you say, a company like Ford cannot get it wrong. It's also true that other vehicles such as SUVs and Minivans are not tested much, if at all, to see how they tow. The bulk of buyers in the market for an SUV or minivan don't want to tow so it's wasted money for the manufacturers. Ask for a tow rating, though, and they'll offer you something well within the vehicle's capacity but won't, indeed can't, back that up with any meaningful data other than tire and axle loadings which, incidentally, are set by the manufacturer of the part, not the vehicle's manufacturer.

Better minds than mine have set up towing systems that go beyond the published design specification for a given vehicle, including the X5 as originally mentioned by the OP. Testing and real world experience has proven that these systems work so in my view, shouldn't be ignored when looking for a tow vehicle and trailer combination. However, if you're not happy to go beyond the manufacturers' recommendations then all is well and you'll still find that match of TV and TT that you require.

[Road Ruler]

Originally Posted by MaxTow

Now back to the OP's questions of the suitability of a BMW X5. As in most vehicles, I don't look at the tow ratings, but at the payload as a starting point. The X5 (Canadian Spec) X5 35d has a maximum payload of 585kg (1290 lbs) If the intended application is pulling an Airstream with an 880lb tongue weight then this does not leave much for anything else inside the vehicle. If we allocate 350lbs for driver + passenger*, plus 50lbs for a hitch then we are at maximum payload. (plus watch any options, as they also eat into this payload specification)

Yes, with our car we are in the same boat with a limited payload capacity.

But the beauty of having a good sized Airstream with a generous payload capacity is that most of the goods we carry go in the trailer, not the TV. This arrangement works great for us.

[sierrafun]

Originally Posted by OrangeKid

Where did you find the Mercedes payload spec? According to Consumer Reports the GL450 has a maximum load (different than payload spec?) of 1210 lbs and the GL320 (2009 model) has a maximum load 1155 lbs. I could not find a maximum load or payload spec listed on the Mercedes Benz site. I have checked many SUVs and most have a maximum load rating of between 1100 and 1400 lbs. According to the 2113 MB Owner's Manual the maximum tongue weight rating of the GL is 600 lbs.

Hi OrangeKid,

I found the Mercedes Payload specs by calling Mercedes corporate and speaking with their customer service department. They then researched the information with the engineering department and provided me with the information. Attached is a spreadsheet I created which outlines not only the GL's payload but others as well. PLEASE NOTE THE MODEL YEAR of the vehicles I researched. This is especially important for the Toyota Sequoia as the payload changed in the 2011 and 2012 models.

Hope this helps you

Kindly,

[Bill M.]

Nice job!

[TouringDan]

Sierrafun

Great job on all the TV specs. After looking at all the results on your spreadsheet, I don't feel so bad knowing that I am towing my 66TW and am over my GVWR (6900 lbs) by only 60 lbs.

Dan

[Road Ruler]

.......and it boggles my mind that a large, Hemi, quad cab Ram that weighs almost twice as much as our mid size sedan can only carry 150lbs more than our car. What's wrong with this picture???

[sierrafun]

Thanks so much Bill and Dan for the nice compliments

@ RoadRuler:
Please keep in mind that the Dodge Rams I specked (both 1500 and 2500) are 4x4 and also top of the line in terms of trim (Laramie Limited).

This is important to note because the payload and tow ratings increase with the 4x2's and also fewer bells and whistles.

Being a lady, I tend to like bells and whistles in my SUV's & trucks which is what I specked for all the vehicles in my spreadsheet

[MaxTow]

Originally Posted by OrangeKid

Where did you find the Mercedes payload spec? According to Consumer Reports the GL450 has a maximum load (different than payload spec?) of 1210 lbs and the GL320 (2009 model) has a maximum load 1155 lbs. I could not find a maximum load or payload spec listed on the Mercedes Benz site. I have checked many SUVs and most have a maximum load rating of between 1100 and 1400 lbs. According to the 2113 MB Owner's Manual the maximum tongue weight rating of the GL is 600 lbs.

Pulled from the Canadian Mercedes Benz site:

Mercedes-Benz Canada - Facts & Figures - Technical data

[MaxTow]

Originally Posted by MrUKToad

Maxtow,

Thanks for your very considered view on manufacturers' design ratings, the more input the better I think.

In terms of the means by which vehicle tow ratings are set then I'd again refer you back to the Truck Trend article, in which named figures from the manufacturers themselves say that it's more to do with marketing and competition. Indeed, the thrust of the article is to highlight the new SAE ratings system which is supposed to provide the market with proper and measurable methods of arriving at a tow rating, simply because tow ratings have been allowed to be set by marketing men and lost their true value.

Where I do agree with you is that certain vehicles, pick-ups especially, are tested in towing situations, quite often to the point of breaking them - it's the market they serve and as you say, a company like Ford cannot get it wrong. It's also true that other vehicles such as SUVs and Minivans are not tested much, if at all, to see how they tow. The bulk of buyers in the market for an SUV or minivan don't want to tow so it's wasted money for the manufacturers. Ask for a tow rating, though, and they'll offer you something well within the vehicle's capacity but won't, indeed can't, back that up with any meaningful data other than tire and axle loadings which, incidentally, are set by the manufacturer of the part, not the vehicle's manufacturer.

Better minds than mine have set up towing systems that go beyond the published design specification for a given vehicle, including the X5 as originally mentioned by the OP. Testing and real world experience has proven that these systems work so in my view, shouldn't be ignored when looking for a tow vehicle and trailer combination. However, if you're not happy to go beyond the manufacturers' recommendations then all is well and you'll still find that match of TV and TT that you require.

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.

As for minivans and SUVs, you are correct - in the absence of significant testing, a manufacturer might decide to be ultra conservative in the specifications. However payload is something that all users need, so this is a detail that will get examined very closely both during design and system validation.

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.

My personal search ended with a Ford F-150 with the HD Payload package. This gives me a payload capacity of 2150lbs. But I want to be able to load up the truck with canoes, 4 people and a specialized bicycle and wheel chair for my son who has CP in addition to towing the AS. Is the truck ideal? No - I would like something more comfortable, and something that's not as big...but it fits my overall needs the best.

(BTW, we're changing from a '04 Toyota Sienna pulling a 20' SOB...kudos for pulling the AS with the Toyota. I'd love to see how that drives for comparison)

As for setting up 'underrated' vehicles for higher capacity towing - I can understand strengthening a hitch receiver for the forces involved. And towing more dead weight means more wear and tear on the TV's drive train - but that should not be a safety hazard (within limits) - just an issue of longevity. But I personally draw the line at overloading a vehicle.

Product testing is tricky business. To truly test design limits, one needs multiple samples and then test each to failure. This is not practical for anybody other than the manufacturer to replicate. So does this mean potentially passing up very capable tow vehicles that have ample margin for the job? Likely. But the point is, we (I) don't know which ones without the manufacturer's specifications.

[MaxTow]

Originally Posted by sierrafun

Hi OrangeKid,

I found the Mercedes Payload specs by calling Mercedes corporate and speaking with their customer service department. They then researched the information with the engineering department and provided me with the information. Attached is a spreadsheet I created which outlines not only the GL's payload but others as well. PLEASE NOTE THE MODEL YEAR of the vehicles I researched. This is especially important for the Toyota Sequoia as the payload changed in the 2011 and 2012 models.

Hope this helps you

Kindly,

Great Table!!

Be careful with calculating the payload capacity by subtracting the published curb weight from the GVWR.

The published curb weight will most likely be the minimum for the trim line being listed. Any additional options will add to this curb weight and therefore reduce the payload capacity.

In the case of my F150 recently purchased:

GVWR - Curb Weight = 2484lbs.

But by adding options such as the Max Tow package, running boards, etc, the maximum payload as listed on the label on the drivers door is 2150lbs.


Also - in the summation of payload requirements don't forget to add the weight of the hitch. In the case of a Hensly or Propride this is heavy at about 200lbs. Then of course there's the tongue weight of the AS (or portion there of if using a WD hitch)

[TouringDan]

[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

[MaxTow]

[QUOTE=TouringDan;1216015]

Originally Posted by MaxTow

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.

[morgandc]

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

[mefly2]

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.

[59ORLander]

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?

[jcl]

Originally Posted by 59ORLander

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.

Jeff

[dkottum]

"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.

[59ORLander]

Originally Posted by dkottum

"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