2013 Cayenne diesel TV

[SteveNdebbie]

Sandy?..,Sandy?....Nice going guys. You scared her away from the forums! [emoji79] Well, Happy Halloween Sandy [emoji316]

[jcl]

Originally Posted by uraljohn

Idea! Maybe a new Federal Regulation that requires any vehicle towing a trailer of any kind be required to "Cross the Scales" located along all major Highways. ….. This would be a game changer. Just sayin, IMHO.

The concept exists for commercial vehicles.

For non commercial carriers, it comes back down to respecting axle weight ratings, and scales would help with that. Good idea to respect axle weight limits, and I don't recall anyone suggesting that they be ignored.

The discussion has largely been about tow ratings, and since they aren't covered by regulations, scales wouldn't seem to have a role to play.

[Countryboy59]

Originally Posted by uraljohn

Idea! Maybe a new Federal Regulation that requires any vehicle towing a trailer of any kind be required to "Cross the Scales" located along all major Highways. In my professional driving career(39 years) covering over 1.5 million miles driving Class 8 trucks (18 Wheelers) I have "Cross the Scales" thousands of times. If your overweight, you pay a fine. Last I checked it started at $100.00 and then 10 cents a pound for every pound over the max allowed weight. Your weighed by the axle. If your more than 10% over, you are not allowed to proceed until you lose some weight. That would severely reduced the idea of putting whatever you wanted behind whatever you drive regardless of how much overweight/capacity it might be. After a couple of $200.00 or $300.00 fines it might change some thinking. More than likely the vast majority of the folks out there towing the family camper have never Cat Scaled there rig. Most of the folks I have talked to since we purchased our Airstream in May, 2017 have never scaled. This would be a game changer. Just sayin, IMHO.

Yeah that would be awesome. Then all the overweight vehicles could stay on back roads like they do now. The lines at the weigh station would be miles long, but we could build extra lanes with all those fines. A perfect example of solving a problem that does not exist. If lots of laws make you feel better, Just fit all vehicles with transponders and cameras. Link it to checking accounts. Offer select insurance (or don’t require it) for those of us who don’t drive like idiots. Wouldn’t bother me a bit but my commute would soon become much less crowded. All of you legal eagles good with that? I didn’t think so. But keep complaining and we will certainly get it.

[pteck]

This will get lost and buried just like all the other opinions here. But perhaps it'll get some enterprising individuals to consider more specific details than the typical power, brakes, etc.

As largely non-technical people, we often conflate and confuse talking points, which has most everyone talking past each other. A common one is strength vs durability.

We know the stock unibody on typical passenger based vehicles are simply not up to the job, stock. Not hard to surmise, as it's not rated by the manufacturer. Has to be braced by shops like Andy's. And it's often said that after initial setup with WD, one may have to tighten by another chain link, shim, etc. as the structure takes a set, i.e. bends, distorts. That sure does not speak well to strength. A persistent owner might continue despite this minor detail.

Durability. Given the strength issue above, I would certainly question long term durability. Durability is very distinct from strength. Unibody stiffness is often confused with durability. Quite the opposite really. Very stiff without enough structure (aka unibody) will actually prematurely fail under repetitive loads. Structure flexibility is actually a durability asset. That's not all though...

Suspension. These nice fancy modern multilink suspensions that underpin passenger based vehicles are supported by many a rubber bushing. Every joint/link typically has one on account of NVH, totaling 30-40++ between the control arms, steering linkages, subframes, etc. Cars that don't tow, typically have many of these bushing begin failing at 100k miles. Making for a sloppy handling vehicle. Sure, she may tow well for the interim, but long term durability? Ever look into the labor and parts costs to refresh a suspension? I won't scare you, ask a friendly mechanic.

An an engineer and hobbyist that likes to wrench on many a vehicle, I wouldn't put my confidence in overloading a passenger based vehicle. Towing straight ahead is one thing. OEMs have to validate way beyond that, for stressful dynamic loads, and meet durability requirements. I'm not against modifying either, and I regularly do that with my vehicles. But I recognize the trade-offs and compromises, potentially to usable life, and I'll pay to play when hot-rodding vehicles.

I'm not specifically knocking the Cayenne. I have and wrench on Porches, and love them. The Cayanne is probably a bit more suited than most unibody SUVs. It's not my first choice, especially as an owner obviously has the funds to purchase a different more suitable choice. Doesn't mean an HD truck either, as that's far from my second choice.

[Pillow]

Originally Posted by Tom_T

Allessandra,

CanAm has gone to 30' AS with CayTDI - see "Hitch Hints" article starting on pg. 6 -

http://rvlifemag.dgtlpub.com/?i=2546

This!

I have towed a good handful of setups over the years and would stay away from a 250/2500+ series truck at all costs for a mixed use vehicle for recreational trailer. With a good WD hitch you are all set for most applications.

We tow mostly with the wifes Escalade ESV now and it is effortless. I suspect a Cayenne with the power and capability would be effortless as well.

Dont under think it, but dont over think yourself into some ridiculous rig that is complete garbage for a daily.

For those who have not driven a Cayenne, you should take the opportunity. It will make you rethink what an SUV should be.

[gypsydad]

Originally Posted by jcl

The payload sticker on the door is a starting point, but it isn't the end point. I would pay far more attention to the axle weight ratings printed on the door label. They have a legal basis, and the comments you are quoting are about the legal aspect

Payload is often reduced, on the door sticker, from what the vehicle is designed to carry, simply because there are some restrictions in where you can physically carry that load. If the trunk is physically located behind the rear axle, published payload can be greatly reduced from the vehicle's potential capacity simply because of the placement of the load (due to the design of the vehicle). So now, consider the use of a WD hitch, properly set up. You get around the rear axle rating limit (which is by itself a hard stop, in terms of a real limit) by shifting weight to the front axle, which has room, all while not exceeding the total load that the vehicle can safely handle.

This isn't being a daredevil, it is engineering.

Now you've done it! Suggesting "engineering" is only understood by a few folks, perhaps? (My early major was mechanical engineering, BTW!)

But the Legal question or liability for modification of a vehicle lies on the owner, right? I think we asked this earlier in a "few" other posts on this topic. here on the Forum..."will the business who "modifies" your sports SUV stand behind you with liability insurance, should you get into an accident of any kind, if you are over Mfg. loading spec's." Seems most folks who are happy with their modified TV don't really care anyway, so it all becomes just a moot point... (but still makes for a good argument!)

[Tom_T]

Originally Posted by EarlM

Don't fall prey to the support of breaking the towing requirement of the vehicle manufacturer. There are lots of folks on here who would tow a big trailer with a Tonka toy.

The tow capacity of your Cayenne is around 7500 pounds---end of story the trailer you are considering will exceed that amount empty with out water, food, clothing etc.

Ask you selling dealer, you will hear all the B/S stories but the fact is the legal limit to tow is 7500 Lbs.

I have a 33 foot Classic and had a 30 foot Classic and would not tow either with my 2018 Cayenne.

I use a 3500 GMC Denali Diesel single rear wheel and enjoy the ride.

Another consideration is the legal tongue weight on the Cayenne.

Your trailer will exceed that also.

Best wishes

Earl

Allessandra -



Check with other Cayenne owners in your local PCA &/or POC Porsche club(s) to ask about their towing experiences, as well as contacting Andy Thompson at CanAm (call/email), & the links to the Hitch Hints article & Cay/T-reg/Q7 owners' topic link on here which I gave you in my prior post above.


Also - do get a good weight-distributing + anti-sway hitch. We got a Hensley Cub for our 3500 lbs wet & loaded vintage kin Avion T20, but you'd need their larger capacity Hensley Arrow or Pro-Pride or one that Andy used on the CayTDI in the article, or something else that he recommends.



Also - if not done yet, do get the "fix" done on your TDI at the dealer - it's a no cost to the owner recall due to the VW DieselGate settlement



.



Earl & Allessandra -



The factory tow rating on ALL Cayennes is 7716 lbs, as stated here, & the HW is 770 lbs load bearing/non-WD (IIRC WD is over 1000 lbs.). Look at the sticker on your factory tow hitch for the actual factory Porsche & German TUV tested ratings for your respective Cayennes (TUV is like our US-DOT doing the SAE/ASTM tow rating test, sorry I don't recall the J number for that test offhand).



While the German TUV, EU & UK areas' authorities still prohibit WD hitches (& so the owner manuals must state so), here in the US & Canada we do allow it, so the WD or Distributed wt. rating for the Cay/VW/Audi, BMW, MBZ, etc. Euro SUVs' hitch rating DO apply.

.



Earl -



I think that you're giving Allesandra some misinformation on the tow rating of Cayennes, so I suggest that you read the sticker on your own Cayenne's hitch to see what the actual factory/TUV/US-DOT rated capacities are for the vehicle.


While some are suggesting exceeding tow ratings on here - I & most others are not, but rather to work within the actual WD ratings, & to properly set-up & adjust her trailer & it's loading to work within those limits.



The Cayenne is a far more stable TV platform with a lower center of gravity & better braking - than are the overly jacked-up full-sized 1/2 & 3/4 ton pick-ups & SUVs by the Big 3 & Toyota/Nissan.



Unfortunately, they have gone to attracting to 20-30-something off-road & cool truck hotshots - to the detriment on either work, TV or everyday use trucks - by putting in suspension extensions of 12-24" that adds nothing to suspension travel & leaves the truck beds above belt level for loading/unloading, & a ludicrous climb up into the cab!



Remember that you can affect your AS's HW by how you load your trailer, with heavier items & tanks over or behind the trailer's axles, & can easily see the affects & play around with loading using a Sherline Hitch Scale (or sim.) to get it within the listed WD HW for a Cayenne.



And unless your `18 Cay is the Turbo V8 - it only has the 3.6L or 3.0L TT V6 (gone to 2.9L in 2019 MY IIRC), & its HP & Torque would be more of an issue on grades with towing your larger ASs - than would her TDI or any V8 Cay.



VW/Porsche/Audi screwed up on the DieselGate - so those 3.0L TDIs are gone here in the USA as a new model, & they'll probably drop all diesels worldwide soon.



Unfortunately Porsche had dropped the normally aspirated V8 CayS in 2015 MY - which was the best MPG Gas V8 for towing (good HP/TQ too). It would get 13-17 mpg while towing - nearly what the TDI got while towing, but without the higher maintenance costs of any diesel powerplant by any maker.



Porsche has followed the pack in going with smaller turbo powerplants to meet the upcoming CAFE & EU fleet MPG targets/Limits, rather than keeping the normally aspirated V8 as the CayS, then adding the 3.6/3.0/2.9L V6 TT as the Cay SC or some other sub-model.



Many of my fellow PCA Zone 8 Cayenne owners have been successfully towing equally heavy race/concours car trailers with their Cays since 2004 with great success, & those trailers are far less aerodynamic than an AS - whether open or enclosed.



So your fears are unfounded - go to RennList website & talk to other local PCA &/or POC members who do tow with their Cayennes, if you doubt me!



Also, try hitching up you Cayenne to the 30' classic & give it a test run, before you unknowingly claim that it cannot be done safely.



.


Big truck types -



Keep in mind that the mid-sized V8 & TDI powered SUVs/CUVs which are tow rated up to 7700-8000 lbs., can have a much higher power-to-weight ratios as well as equal or better net useful load (GVWR - Curb Wt. + HW) than the bigger & heavier 1/2 & 3/4 ton trucks - while being much more comfortable & fuel efficient.


The stock base Ford F150 is only rated for 5000 lbs towing, while Allessandra's Cayenne 3.6L TDI is rated for 7716 lbs. - as are ALL Cayennes/Touaregs - including the base Cayenne/Touareg gas V6 3.6L (except the Hybrid's, which are reduced by battery wt., & the longer 3-row Audi Q7s, reduced by the added wt. of longer & 3rd row body).


That is 150% of the base F150!


Moreover, the 5.0L V10 TDI Touareg in the video below clearly out pulled the Chevy 2500 or 3500 Duramax 6.9L in the Diesel match-up in the video below.

https://www.youtube.com/watch?v=k62gW3Se5e0

Also, as I stated above - the Cayennes & other lower CG SUVs are more stable TV platforms, are far more comfortable than juggling your kidneys on a long trip - & you won't need a step stool to load/unload the cargo area or climb way up into the cab.



Perhaps if Ford/GM/Dodge-RAM still offered more comfortable riding & reasonable height trucks/SUVs like they did in the 1950s thru early-2000's - with the jacked-up treatment as an option - then they might still be more reasonable TV options.



As it is, many of my colleagues in the construction industry are suffering higher workers' comp claims due to back, shoulder & other injuries due to their workers lifting into3-4 foot high beds!



How the heck is that reasonable or good automotive/truck design!?



We have rented both gas & diesel 3/4 ton F250/350s & RAM 2500s from Enterprise Truck Rental to tow our Avion - so I know exactly what a PITA they are to CLIMB up into an overly lifted truck, sit in uncomfortable seats, & have your guts juggled around for 800-3400 miles!



Nuff said - full-sized trucks today are just pompous jacked-up wastes of time IMHO!



Cheers!
Tom
///////

[Tom_T]

Originally Posted by gypsydad

Now you've done it! Suggesting "engineering" is only understood by a few folks, perhaps? (My early major was mechanical engineering, BTW!)

But the Legal question or liability for modification of a vehicle lies on the owner, right? I think we asked this earlier in a "few" other posts on this topic. here on the Forum..."will the business who "modifies" your sports SUV stand behind you with liability insurance, should you get into an accident of any kind, if you are over Mfg. loading spec's." Seems most folks who are happy with their modified TV don't really care anyway, so it all becomes just a moot point... (but still makes for a good argument!)

Gypsydad -



Will Ford on yours, or any other of the Big 3 & Toyota/Nissan, also "stand behind you with liability insurance" for their overly jacked up trucks' factory lift kits, if you roll it or lose control due to the taller trucks' higher center of gravity causing instability?


Will they stand behind you for medical &/or workers comp insurance if you &/or others injure themselves trying to load/unload that super high bed, or climbing up into the bed or cabin?


I can tell you that they do not from anything I've heard from friends & colleagues with those problems!



In all probability it would be far more likely to prevail in a liability case (full or partial), against the smaller company who installs or modifies any TV (including those on full sized trucks/SUVs & with mid-sized SUVs) - vs. trying to get anything from a major vehicle manufacturer, as a private citizen trying to go up against their fleets of high paid in-house & outside Legal Counsel!



Let's talk reality here & stop "the sky is falling" scare tactics!



Cheers!

Tom
///////

[Tom_T]

Originally Posted by pteck

We know the stock unibody on typical passenger based vehicles are simply not up to the job, stock. Not hard to surmise, as it's not rated by the manufacturer. Has to be braced by shops like Andy's. And it's often said that after initial setup with WD, one may have to tighten by another chain link, shim, etc. as the structure takes a set, i.e. bends, distorts. That sure does not speak well to strength. A persistent owner might continue despite this minor detail.

Pteck -



The mod which Andy's shop does is to distribute the hitch wt. further up to the front of the rear suspension, in order to avoid damaging the hitch itself - not the Cayenne/Touareg/Audi Q7 unibody structure.


Note that there are also many cases of similar hitch & receiver failures at or near the welded joints on the 1/2 & 3/4+ ton truck - whether a factory or aftermarket Reese, Curt, etc. hitch.


So the need for such modification in NOT just a Cayenne thing - it's really required on all hitches - especially with the added torque of a WD hitch.


IIRC Andy's shop also does similar mods for full sized pick-ups & SUVs as well, which consists of a steel tube extension from the forward end of the hitch receiver/tube, up forward on any TV to an appropriate attachment point on the chassis/frame.


So don't over play this as a smaller TV only issue - it occurs on all types & sizes of TVs & hitches.



Cheers!
Tom
///////

[Tom_T]

Originally Posted by jcl

A fact-challenged post.

While the recommended tow rating is 7700 lbs, that doesn’t necessarily represent the maximum tow vehicle capacity. It represents a Euro regulation of 3.5 metric tons as a cut off point for a different set of towing regulations in Europe.

The trailer under discussion weighs under 6000 lbs empty.

There isn’t a legal tow limit. We are discussing private vehicles, not commercial carriers. Show the regulation.

There is no such thing as a legal tongue weight. There is a legal axle load limit. They aren’t the same.



Just one of the issues....

jcl -

Good info on the 3.5 m-ton Euro towing limit.

They also expressly prohibit WD hitches by law over there in the UK & most other European countries, which was apparently done back in the 1960s or `70's to protect the UK & European lighter weight trailer manufacturers, from the burgeoning US trailer makers coming over there with our generally heavier trailers of the day & using WD to accommodate them on Euro/UK vehicles.

Whether or not technically a "legal limit" - the Cayenne factory hitch stickers do list the factory ratings for trailer wt. & both hitch wt. non-distributed & distributed.

Another excellent feature of the Cayenne/Touareg/Q7 factory hitches from 2004 or `05 on - is that they are linked to the vehicle's electronics, so that whenever you put that tow bar into the receiver hole, it automatically puts the vehicle into tow mode & keeps it there until the tow bar is removed. So you automatically have the engine, transmission, transfer case, differential & brakes all in the tow mode mapping for them.

This is unlike the typical full-sized truck/SUV where you have to manually select tow mode every time you start/stop the engine, which is a PITA - especially if you happen to forget to do so!

Cheers!
Tom
///////

[Tom_T]

Originally Posted by EarlM

Sandy,

There seems to be some folks that are self proclaimed experts. It is your money and the safety of your family that is important to me not my EGO.

I would suggest you determine the actual weight of the trailer you are thinking about buying and add water and other necessities, weight is the final determining factor

Then ask your Porsche dealer to put in writing the maximum towing capacity and how much weight you can apply to the hitch.

Then ask your Airstream dealer if he will sell the trailer to you with it attached to the Cayenne.

Earl

Ummm Earl -



All Cayennes have their tow ratings both on the vehicle door sticker & hitch sticker, & in the owners manual (which I know many don't read anymore) - so I think that qualifies as "in writing" already done.



But - yes - she needs to match the trailer wt. as wet & loaded - & loaded to stay within the WD hitch wt. rating, which could include such strategies as putting the heavy items in the rear, &/or an appropriate AS approved trailer bumper bike rack & bikes, at the rear - in order to rebalance the HW to be within the limits.


For those ASs & other trailers with more than the normal 10-15% HW - it's usually because the manufacturers have put heavy stuff up front, &/or the owners have opted for extra batteries, larger LP tanks, etc. on the trailer tongue - causing a trailer to have a higher Hitch wt.


Apparently Lucille Ball isn't the only one to put heavy junk in the front of trailers! (refer the the movie "The Long Long Trailer" for this reference.)



Also of note - the Hensley & ProPride PPP-type of hitches don't need the 10-15% HW on the ball, due to their unique design with the balll/coupler enclosed within the articulating hitch-head - so a 7716 lb. trailer wouldn't need 772 - 1156 lbs HW - but the Cayenne is rated at 770 lbs. non-distributed HW with 7716 lbs trailer wt - which is 10%.



I don't know if that also applies to Blue Ox, Equalizer & some of the other WD hitches.


Cheers!
Tom
///////

[Tom_T]

Originally Posted by SteveNdebbie

Sandy?..,Sandy?....Nice going guys. You scared her away from the forums! [emoji79] Well, Happy Halloween Sandy [emoji316]

Maybe she went over to the Cayenne/Touareg/Q7 thread for a more friendly environment!?



Cheers!
Tom
///////

[rmkrum]

Originally Posted by Tom_T

---------------------snip------------------------


Also of note - the Hensley & ProPride PPP-type of hitches don't need the 10-15% HW on the ball, due to their unique design with the balll/coupler enclosed within the articulating hitch-head - so a 7716 lb. trailer wouldn't need 772 - 1156 lbs HW - but the Cayenne is rated at 770 lbs. non-distributed HW with 7716 lbs trailer wt - which is 10%.



I don't know if that also applies to Blue Ox, Equalizer & some of the other WD hitches.


Cheers!
Tom
///////

ANY hitch setup needs 10-15% of the trailer weight on the hitch...there is nothing about the ProPride or Hensley that makes an overly light hitch weight safe to tow. TW is about proper stability when towing--an articulating trapezoid design does not help you with an overly light tongue weight. The Hensley design hitches are there to eliminate sway, and I submit that too much rear loading (and a light tongue weight) can overcome even a Hensley design hitch system's inherent sway prevention--or send the whole rig out of control, or worse, break things...

Don't know where you are getting this, but it's not in my ProPride manual...proper trailer loading in any case requires 10-15% weight on the tow vehicle...then enough WD bar tension to re-load the Tow vehicle fron axle to keep it on the ground properly...

As an example, my rig (yup the TV is a bit light) is VERY sensitive to WD, and will both porpoise and act badly when steering it if the WD is a little light. I have to tune my WD to the load to keep it stable on the front end--which is the point of WD, IMHO.

[pmclemore]

I would cheerfully pull my 30 footer with a cayenne, especially with a hensley hitch and set up by CanAm.

But I love my 2500 duramax because of all the other stuff I carry around. I believe I would have to be more disciplined without it.

Pat

[gypsydad]

Originally Posted by Tom_T

Gypsydad -



Will Ford on yours, or any other of the Big 3 & Toyota/Nissan, also "stand behind you with liability insurance" for their overly jacked up trucks' factory lift kits, if you roll it or lose control due to the taller trucks' higher center of gravity causing instability?


Will they stand behind you for medical &/or workers comp insurance if you &/or others injure themselves trying to load/unload that super high bed, or climbing up into the bed or cabin?


I can tell you that they do not from anything I've heard from friends & colleagues with those problems!



In all probability it would be far more likely to prevail in a liability case (full or partial), against the smaller company who installs or modifies any TV (including those on full sized trucks/SUVs & with mid-sized SUVs) - vs. trying to get anything from a major vehicle manufacturer, as a private citizen trying to go up against their fleets of high paid in-house & outside Legal Counsel!



Let's talk reality here & stop "the sky is falling" scare tactics!



Cheers!

Tom
///////

Yes, lets stay in reality. The sky is not falling....yet! But, your claims highlighted are a bit far fetched also...IMHO..
I know the big companies would stand behind their vehicles/trucks if something were to happen under "recommended" use conditions, should a part fail. (Trying to "load/unload" does not fall into the category I was referring to, Tom.) If you have some "experience" otherwise as you suggest, please share with us...

But, I know some folks get riled up about challenging their decisions on using a sports SUV...especially when truth about legal liability comes up...doesn't mean they are correct for suggesting that "shoe" fits all...reality happens; and better to consider all your options before jumping into costly modifications. We've all heard folks on here that talk about the "old sedan" that can do most anything...but that doesn't mean you should. No offense intended.

[jcl]

Originally Posted by gypsydad

Now you've done it! Suggesting "engineering" is only understood by a few folks, perhaps? (My early major was mechanical engineering, BTW!)

But the Legal question or liability for modification of a vehicle lies on the owner, right? I think we asked this earlier in a "few" other posts on this topic. here on the Forum..."will the business who "modifies" your sports SUV stand behind you with liability insurance, should you get into an accident of any kind, if you are over Mfg. loading spec's." Seems most folks who are happy with their modified TV don't really care anyway, so it all becomes just a moot point... (but still makes for a good argument!)

I was defining engineering as the practical application of science. I made no comments on individuals, just on the definition of what is being done. This can be contrasted with calling people "daredevils", which was posted above, and using scare quotes.

I have never modified a vehicle to tow more than its capacity. Improve handling through different tires, shocks, certainly, I have done that. I also have no issue with modifying a hitch receiver when it isn't strong enough. When you refer to modifying tow vehicles, some may be led to believe by your comments that the vehicle itself is being reinforced. Not so. Strengthening a receiver hitch is commonly done on everything from SUVs to one ton pickups (when the manufacturer supplies a receiver that flexes and thus doesn't adequately transfer weight back to the front axle). Lots of examples all the way up through RAM and GM products. Is that modifying a vehicle?

[gypsydad]

[QUOTE=jcl;2174957]I was defining engineering as the practical application of science. I made no comments on individuals, just on the definition of what is being done. This can be contrasted with calling people "daredevils", which was posted above, and using scare quotes.

I have never modified a vehicle to tow more than its capacity. Improve handling through different tires, shocks, certainly, I have done that. I also have no issue with modifying a hitch receiver when it isn't strong enough. When you refer to modifying tow vehicles, some may be led to believe by your comments that the vehicle itself is being reinforced. Not so. Strengthening a receiver hitch is commonly done on everything from SUVs to one ton pickups (when the manufacturer supplies a receiver that flexes and thus doesn't adequately transfer weight back to the front axle). Lots of examples all the way up through RAM and GM products. Is that modifying a vehicle?[/QUOTE]

Well, that's the million $ question here, isn't it? What, if any modification, is considered modifying the original vehicle beyond it's intended use. I know you can add a trailer hitch after market to just about anything, and pull a trailer...I've done it in my younger days to a full size van and also later to my Honda Pilot, to pull my boat. Never even considered if that was a problem on either of those vehicles..I just took it to the trailer shop, and they welded on a hitch to my frame, both times. I didn't even know if the hitch they put on was too small or not for the weight of my boat at the time...just trusted they knew what they were doing...and, maybe they did. No one here has been able to comment with any certainty weather there could be legal issues for modifying beyond the manufacturers recommended loading limits. Seems to me the owner is liable but if for some reason, a "weld" fails or a bolt breaks caused by overstressing something and the original vehicle is out of spec, who knows?

[jcl]

Originally Posted by gypsydad

Now you've done it! Suggesting "engineering" is only understood by a few folks, perhaps? (My early major was mechanical engineering, BTW!)

Sorry, I don’t understand the phrase “early major”. Does that mean your first degree, or courses that you took before moving on to something else entirely?

I think it is very obvious that engineering principles are not uniformly understood by all. Some here regularly confuse hp and torque. Others equate a given tongue weight to an equal addition to rear axle loads. Some think that 10-15% tongue load is an absolute, not considering the variables around towing speed, rotational moment of inertia of the towed vehicle, the fact that Euro trailers are designed for 5%, and so on. And let’s not even start on those who don’t understand four bar linkages, equating them to pixie dust in one epic thread.

[SteveNdebbie]

Originally Posted by jcl

Sorry, I don’t understand the phrase “early major”. Does that mean your first degree, or courses that you took before moving on to something else entirely?



I think it is very obvious that engineering principles are not uniformly understood by all. Some here regularly confuse hp and torque. Others equate a given tongue weight to an equal addition to rear axle loads. Some think that 10-15% tongue load is an absolute, not considering the variables around towing speed, rotational moment of inertia of the towed vehicle, the fact that Euro trailers are designed for 5%, and so on. And let’s not even start on those who don’t understand four bar linkages, equating them to pixie dust in one epic thread.

I didn’t do a very good job with my pictures but here’s the modifications to the receiving hitch.

[jcl]

Originally Posted by pteck

We know the stock unibody on typical passenger based vehicles are simply not up to the job, stock. Not hard to surmise, as it's not rated by the manufacturer. Has to be braced by shops like Andy's. And it's often said that after initial setup with WD, one may have to tighten by another chain link, shim, etc. as the structure takes a set, i.e. bends, distorts. That sure does not speak well to strength. A persistent owner might continue despite this minor detail.

Durability. Given the strength issue above, I would certainly question long term durability. Durability is very distinct from strength. Unibody stiffness is often confused with durability. Quite the opposite really. Very stiff without enough structure (aka unibody) will actually prematurely fail under repetitive loads.

This hasn't been my experience with several unibody tow vehicles (Volvo wagon, BMW X5, BMW X3).

I have never had to stiffen a unibody. I am not adverse to strengthening the factory receivers, which aren't typically built for WD equipment.

I have not noticed any loosening of the unibody structure, additional noises or creaks. I have been driving X model BMWs since 2003.

I have never replaced suspension bushings on either X model SUV despite towing use. Many others have, but I suggest it had nothing to do with towing, it seems far more related to the use of wide tires that put excessive loads on the suspension bushings. The X5 (E53 model) was originally designed for 17" wheels. 18" were standard on the V8 model. They offered 19", 20", and larger over the years. That is when suspension bushing failures started.


One of the better references for the E53 platform has been long term poster withidl. His 2001 E53 was used to tow a 31 Classic for many years. I believe he had 35,000 towing miles on it, and over 100,000 miles total. See this thread for his durability report:

http://www.airforums.com/forums/f463...ml#post1414015