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Old 10-16-2015, 02:04 AM   #21
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Originally Posted by Ohiobrits View Post
I believe the difference in vehicle tow rating is the (tow)rating of the receivers fitted in Europe v US. The US version is rated lower than the Euro version (bono is probably right in that it is 6000lbs not the 6600 I stated) The vehicle that it is bolted to is the same (obviously).
It is true that the receivers are different.

The base vehicles are the same (all built in one place) but specific equipment can be different. An example is the smaller engines offered in Europe, which have correspondingly smaller differentials. Those smaller engines make less heat, and so have smaller cooling systems. Some BMW E70 diesels sold in non NA markets had rear differential failures, and while it may be a coincidence, BMW went to a larger differential after two years of production. The North American models always had the larger differential.

In considering a new F15 X5, I was playing around with payload, GVWR, and tow ratings. I noted that for Euro and North American versions of the same vehicle, I could find models with the same published GVWR, to the kg. This was by selecting engines that were common between the markets. I then went to the parts books for each model, and compared them to see what was different, with the Euro model having a larger published tow capacity. I was interested in cooling systems, transmission, differentials, and so on. I matched the vehicles up right down to part numbers. That isn't to say that they don't have different computer programs (since they do) and that might be a factor, but the things that I worried about looked good. I was not going to use the Euro hitch (no WD, tongue weight limit) so I would use a North American dealer-supplied hitch, with reinforcement.

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Old 10-16-2015, 02:16 AM   #22
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I would really love to know.

Are there ANY differences in manufacturing? Something about right vs left hand drive? Different bolts from different suppliers for US vs Euro versions? Some analysis of general road conditions/expectations? Driver habit studies?

I can't imagine it's arbitrary even though it sounds that way. If t really were arbitrary why change the rating at all? ��
An anecdote. An earlier X5, in this case a 2003 E53 model. The door sticker did not mention tow rating. The owner's manual did not mention tow rating. It did talk about GVWR (no GCVWR), and it did talk about roof rail load rating, but not towing. Zip.

There was no factory hitch offered, but there was a dealer supplied BMW hitch, which in my case I installed myself using the BMW tech info. There was a full page in the instructions about applying the weight capacity sticker when installing the hitch. This hitch had a 6000 lb rating, 600 lb tongue weight max, max offset for drop and extension from the pin, 1600 lb rating with no brakes, and 3200 lb rating (IIRC) for off road use, presumably related to bounce. But all of this was a hitch rating, not a vehicle rating. It was widely regarded as the vehicle rating, but was simply a result of the decision by BMW NA to outsource a 2" square receiver hitch to a Northeastern US fabrication shop. I think the decision to design that receiver for 6000 lbs instead of the 7700 lbs the vehicle was designed for was very arbitrary, given that the receivers used the same mounting bolts. BMW even went cheap on the instructions; the ones that came packaged in the hitch box showed the Euro swan neck style hitch.

I can imagine the product meeting at BMWNA, which is a marketing organization, not the product engineering and development group. "We need a hitch. What type? Make it a Class III" (which is what they advertised it at). Some product development person went back to his desk, and did research on what a Class III hitch was. He decided it was 6000 lbs, and that was that. Having worked with German design engineers, I can imagine that if they wanted to make it 7701 lbs there would have been no way, but as long as they were under the vehicle design number, they were fine.

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Old 03-19-2016, 10:16 PM   #23
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It took me a while to get to CAT scales, but finally I got there:

Total weight of the vehicle with passengers and cargo: 6,080 lbs
Rear axel: 3,240 lbs
Front axel: 2,840 lbs (I just deducted 6,080 – 3,240, as they said they could not weight front axel… do not ask why)
Approved gross vehicle weight (per manual): 6,261 lbs
Remaining payload: 181 lbs

I had 2 passengers in the back who weigh total 450 lbs and would not travel with us when towing. This gives me more less 650 lbs payload available. I expect that the trailer which I will be towing will have tongue weight in the range of 800-900 lbs, so I might be 150-250 lbs over approved gross vehicle weight.
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Old 03-20-2016, 09:29 AM   #24
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The Airstream literature tongue weight of our 2015 23D was 720 pounds with a GVW of 6,000 pounds.

After all of our extensive modifications and installing a Hensley Arrow hitch, the camping ready tongue weight (all our stuff and food) with full fresh water and full propane in the two 30 pound steel tanks is 928 pounds with a total scaled weight of 6,068 pounds.

By careful placement of the Honda 2,000 watt generator, air pump, camping chairs,and grill etc inside the Mercedes ML320 CDI (competitive model to the X5) we do not exceed the axle and tire ratings of the car.

We tow at 55 mph and follow the advice of the yellow caution speed limit signs. The decrease in fuel economy to go 65 mph is significant (nearly 25%) and there is a lot more wear and tear on both the driver and the vehicle.

The setup takes patience, but is worth the effort.
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Old 03-20-2016, 04:50 PM   #25
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I will be buying Jayco trailer with 650 lbs dry tongue weight. I am planning to remove the battery from to tongue and move it to inside the trailer in the back (switching to lithium battery) and also I will travel only with one propane tank.

I will have Propride installed, so I will not need that much tongue weight to have the setup stable.

These are the plans... will see how it works in a couple of months.
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Old 03-20-2016, 05:16 PM   #26
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I will be buying Jayco trailer...
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Old 03-20-2016, 05:36 PM   #27
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In my experience with owning, racing and paying for BMW's for the last 25 years you might want to look elsewhere for a tow vehicle. It's like making something do what it is not really set up for. Can you do it ? Sort of.
X5's based on what model and tires you have on it are engineered with negative camber. One of the reasons they handle so well. Some have more than others. Some based on your options - sports pkg, tire and wheel setup, runflat tires have more or less negative camber.
I towed a race car on a open trailer with total weight of 4,000 lbs from Durango, CO to Virginia International Raceway in 2005. When I got into Erie, PA I noticed a funny noise as I drove slowly down a off ramp. Upon examination, I saw the rear tires had become bald on the inside shoulder. Cord showing and everything pretty ugly. I was then stuck in Erie, PA for two days waiting for special tires which they all need. Not fun. BTW the race went in much the same way. But besides the point.
I would say if you are towing short distances and back on a infrequent basis, you can probably get away with it. Would not do it with the runflats, if you have them.
Too stiff a sidewall. Too much heat generation. Too expensive to replace,can't be repaired, etc.
I bought a 2015 1500 RAM oil burner which is excellent. 18mpg on a 1,800 mile tow last summer. It hardly knows my 25' Safari is back there. Cost $33K loaded. Probably still worth that now.
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Old 03-20-2016, 06:06 PM   #28
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Re: my post above.
I was towing with a 2004 X5 4.6 with sports pkg, staggered 20" wheel and tire combo.
Had a friend that towed open trailer with a Z3 racecar. With a X5 3.0. Mostly local around Ohio. Did OK.
Also a longer wheelbase also adds stability to the tow. Coming down a hill pulling a 7,500 lb load is a handle under braking. The AS wants to shove the rear end of a short wheelbase tow vehicle towards the outside of the turn.
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Old 03-20-2016, 08:48 PM   #29
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-- snip -- I saw the rear tires had become bald on the inside shoulder. -- snip -- Would not do it with the runflats, -- snip -- Too stiff a sidewall. Too much heat generation. -- snip --
DHoover - We have 20K on our run flats and they are not showing uneven wear or excessive heat build up. The only problem with the BMW as a tow vehicle is that it is not embraced by BMW for that purpose and therefore, requires significant investigation to define and implement a stable and safe setup. You will note that BMW also does not embrace the off road world.

Have to admit, not sure why run flat stiff sidewalls and light truck stiff sidewalls would not be similar solutions to add towing stability. Might be a good discussion for the tire engineers. Pat
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Old 03-20-2016, 10:57 PM   #30
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I am not saying the runflats are a bed passenger tire. I have put a lot of miles on them myself.
I'm saying they are not a tire I'd like to tow with with the addition of tongue weight compressing the rear suspension. Which changes the contact patch, overall spring and rebound rates and chamber. They have been engineered (and you will see a star on the side wall) specifically for that BMW. And in the operating environment based on BMW specs.
I agree they do not embrace the off road world. But it's not marketed to replace a Jeep Wrangler.
Have you been towing your AS with it ?
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Old 03-20-2016, 11:10 PM   #31
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My experience with several BMW vehicles over the past few decades (and with two of them towing, an X5 and an X3) is that premature wear on the inner part of the rear tires is not particularly related to camber, but is very related to too much toe in on the rears. With excess toe, the tires scrub constantly, and with wider tires such as 20's they can wear very quickly. Camber gets (wrongly) blamed because people can see it from the rear. They just can't see the toe in as easily.

Adjust the toe to the minimum of the BMW spec for your vehicle. Not just into the (too wide of a) range they spec, but to the minimum of it. Works wonders.

As to additional tongue load impacting rear tires, it is always worth checking that you are within designed axle loads, and tire load ratings. With those two in mind, and correct inflation pressures, I wouldn't worry about the rear tires any more than without a trailer, as you will be within the BMW design spec.

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Old 03-20-2016, 11:17 PM   #32
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Dhoover, I think the tires are the last issue I may expect when towing with my X5. I believe that good alignment makes a lot of difference. In order to get as much as possible from tires on X5 you need to get toe to minimum (0.00 - 0.02).

Re runflats – I do not believe in advantages of having runflat, so as soon as I am ready to change the tires, I will be changing to no runflats. Regardless, I do not understand why towing with runflats would be worse than with non runflats… I am new to towing, but I think that lower profile should be better than higher profile, stiffer sidewalls would be better than softer…

BTW, runflats may be repaired… unless the nail is too close to the sidewall… like regular tires. It is only BMW saying that you cannot repair. Of course, if you drive longer distance without pressure, there could be internal damage and I would not put this tire back on the car.

There is another user of this forum towing 8,000 lbs 31 feet AS trailer with BMW X5 E53. I think a good hitch (Hensley or Propride) is minimizing potential issues of short wheelbase.

I will check how my setup works. Bottom line is that I am not going to drive a truck. I would change the trailer, if my setup does not work. The next TV will be Mercedes GL or BMW X7 (will see in 2018 what BMW has to offer).
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Old 03-20-2016, 11:56 PM   #33
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Dhoover - We have over 16K miles towing Glimmer with Bimmer. The contact patch is addressed with correct tire inflation pressure and the air suspension maintains correct ride height. We have not had the problems you describe. Pat
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Old 03-21-2016, 06:59 AM   #34
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To the OP: It seems everything (tow rating, hitch rating, GVWR, axle ratings, and short wheelbase TV) points to a mismatch between your TV and trailer. If I may, I'm going to suggest something to you.

Rent a whitebox trailer for a few days. In the Norhteast, you can rent them for $120 a day (not a huge investment). Pick a camper thats within your vehicle's manufacturer ratings (6000# trailer weight, 600# tongue weight). Pick a shorter camper (say, 27 ft not 34 ft you plan to tow). Go for a short camping trip to assess your TV's abilities. Pick a road that that has some inclines/declines. Assess the pulling/stopping ability of your BMW. Drive in a windy stretch of the road to get an idea of the stability of the combo.

After the trip, assess your BMW and decide whether its a match to tow a much heavier, much longer trailer. FYI, anyone can hitch up their TV to a monster trailer in their driveway, post a photo to an online forum, and brag about their TV. Nothing replaces a real world test.
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Old 03-21-2016, 09:45 PM   #35
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I have noticed that BMW is using the same payload across all X5s.



The suspension is basically the same in 35i, 35d and 50i, and there is 300 lbs difference between the approved gross vehicle weight between 35i and 50i.
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Old 03-22-2016, 12:16 AM   #36
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Air forums will never provide consistent, experienced advice on setting up this combo. Contact the hitching experts at Can-Am Airstream in London, Ontario who have specialized in this work for over 40 years.

They especially like the towing qualities of the X5. They also especially like the towing qualities of Airstreams, but you're heading in a different direction. They have experience there as well and can help you.
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Old 03-22-2016, 07:39 AM   #37
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Thanks Doug. I was in contact with Andy and reinforced the hitch according to his advice. It just too far from California, but I would go there without hesitation to get everything ready for towing.
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Old 03-22-2016, 09:11 AM   #38
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Took my 2007 Mercedes ML320 CDI to CanAm in October of 2012 to have the factory installed receiver reinforced and while there they also pre-bent and shortened the Hensley Arrow stinger. Dropped by again on the way back from the East coast dealer to fine tune the Hensley with the 23D. Andy really knows his stuff and his employees are a joy to be around.
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Old 03-22-2016, 11:45 AM   #39
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Bono - A common payload rating makes sense from an engineering perspective. The drivers for a different engine choice are fuel economy, performance, and initial purchase price. By keeping payload the same, that is one parameter which is not confusing to the purchaser, contributes to the precision of German engineering, and slightly reduces the sea of BMW option choices. Noting the differences in axle capacity leads one to the possibility that each of the models is configured with specific components based on performance and weight parameters. After all BMW does build "The Ultimate Driving Machine".

Unfortunately, what is missing is a clear indicator that the vehicle is over designed for the marketed capacities. The positive is that the chassis is a refinement of prior models and there is experience which indicates an absence of problems on any of the X5 models when used for towing. Your experience may vary, but you have certainly done considerable due diligence to establish the best configuration for your rig.

Remember that a conservative approach, active driving, and actual towing experience are also required to achieve a safe towing experience. The steering is quite sensitive on the F15, so take care not to over correct if you feel a wiggle from a passing vehicle. Also note that the cruise control on the F15 activates the brakes when the rig is over the speed setting. Normally that is a good thing, but in a down hill section the cruise control rides the brakes, which is not a good thing. So go active and control your descents.

When you get the rig, travel safe. Until then, keep learning. It all helps. Pat
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Old 03-22-2016, 01:58 PM   #40
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switz, thanks. I will ask Andy whether they can fine tune ProPride stinger for me.

PKI - I am not engineer maybe therefore the same payload across all X5 s does not make sense for me... apart from making this easy for BMW to print the same stickers with the payload. I checked a few suspension components for different engine versions are they appear to be the same. Therefore, IMO 35i should have 300 lbs higher payload than 50i.

I have E70, not F15 and the light steering on F15 is one of the reasons
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