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One more thing to keep in mind. Comparisons between vehicles should include the type of structure they are built on. The Sienna is a unibody vehicle. The Tacoma is a body on frame truck. I would think the way a hitch is attached to the vehicle would make some difference. A ladder frame in a truck distributes the hitch "pull" along the strongest part of the frame. The mounting points for a hitch on unibody vehicle may not be built in the strongest part of the structure, nor has the same thickness of metal as a frame rail. The additional rails attached to "shinysideup"'s hitch and run further up the structure probably attest to this point.
 

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Structural differences do matter, which is one reason that the frequent comparisons to the Highlander (rather than the Tacoma) in this topic are particularly relevant. Unibody construction is not a serious limitation if attachment points are properly considered, as some unibody vehicles (e.g. Jeep Grand Cherokee) have much higher trailer weight limits than the Sienna or even the Highlander.

I think the Sienna's six welded-in nuts specifically for hitch mounting are much better than the minimal or non-existent hitch mounting provisions on many other vehicles.

I believe that the forward extension of shineysideup's hitch is primarily to handle greater downward force on the front mounting points due to high weight-distribution torque, and to spread the front and rear points further apart, again for weight-distribution torque. I doubt it really helps in the other directions, and since it is a guess-and-weld design by an RV dealer (not a structural design by anyone qualified) we don't really know if it helps at all (although it look reasonable to me).
 

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From the show us what you are towing topic:
jroden said:
I wish I snapped a picture... I met someone atthe campground the other day who was towing a 30 foot airstream w/ his Sienna, he was running the hensley hitch and airbags at about 30 psi. He said he had put 45K miles on the rig towing all over Canada, he said it towed really well. He said it was about 9000 lbs.

I think those airstrems slip through the air a lot better, but still that's pretty impressive.
Impressive, or scary. :eek:

I suspect another Can-Am RV special, especially given the brand of trailer (Airstream) and the use of a Hensley Arrow mega-dollar mega-hitch.

9000 pounds is consistent with a current 30-foot Airstream with full tanks and a bit of cargo; they have aluminum bodies, but they're not light.

The Airstreams have an aerodynamically good front (and probably lousy rear), and they are relatively low for their length. These are features which have been discussed here as making a heavy trailer more acceptable for towing.
 

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Discussion Starter · #44 ·
Brian, take a minute and go to airstream.com/why-buy/index.html There is a video of an airstream and a conventional trailer being towed through a pylon slalom. The end result is scary. I know, I know it could be a setup, after all it is from the airstream manufacturer. :eek: On an aerodynamic note, check out www.johnbridge.com/travel_trailer_aerodynamics.htm You've gotta admit, 45000 miles of towing and the sienna is still kicking ;D. Guess I don't have anything to worry about in terms of reliability... You are correct about my hitch mods, they are for increased transfer ability (thus improving steering, which is always a good thing). Before I had the hitch mods done I had 800lb bars to test tow with. When I bought my rig it came with 1000lb bars... (weight distribution bars that is...) I will take a pic of my setup the next time I hook up. Took my brother for a ride with my rig the other night... he was VERY impressed with the towing traits (he drove transport truck for several years). Guess what? he has a new Hyundai minivan that might get the can am treatment in the near future, I'll make a camper out of him yet! (and his wife wants to also... happy wife, happy house!)

cheers,

shineysideup
 

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shineysideup said:
Brian, take a minute and go to airstream.com/why-buy/index.html There is a video of an airstream and a conventional trailer being towed through a pylon slalom. The end result is scary. I know, I know it could be a setup, after all it is from the airstream manufacturer. :eek:...
Thanks, I did. :)

The aluminum body construction seems entirely irrelevant to me. The Airstream floor (and thus mass) height is lower, the track might be wider, and the suspension might have higher roll stiffness, all of which would help. Also, Airstreams presumably still all have shock absorbers, and my guess is that the "typical" comparison trailer does not; shocks help in transient situations, and these tests exist to create transient conditions.

It's too bad that this marketing stuff doesn't include any hard data. The behaviour different is visually obvious, but the trailer specs are a mystery.

If the comparison basis is fair (that is, if the trailers are the same size, by some reasonable measure), then this illustrates that the full set of trailer characteristics are important, not just the weight. I still get back to the problem that if we don't know which characterstics are important, or what was assumed when the tow vehicle ratings were developed, we're guessing at what the "true" capacity might be with a specific design of trailer.
 

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Discussion Starter · #46 ·
Actually Brian, the airstream trailers brag about the torsion flex suspension that is the same as my trailer. ;) The video specifically states that the airstream was riding on a torsion flex suspension which seems to work quite well to me! I agree, the aluminum on an airstream is very much a love/hate thing for everybody. Airstream trailers are NOT light at all. I think an 18' airstream weighs the same as my trailer. They do have an aerodynamic shape though...as funny as it looks (to some)

There has not been big changes in trailer shapes for decades (the other trailer manufacturers are just as happy to stay with the status quo). There is two newer trailers being made recently... the bullet which actually has sloped sides and an aggressively angled front end, unfortunately it still ends in a box at the back of the trailer (crappy aerodynamics).

Not sure if you have seen the new earthbound trailer yet... This trailer has some big changes in it starting with an aerodynamic front and rear along with lighter weight (compared to conventional trailers) See it at earthboundrv.com I had the pleasure of being in the #4 trailer off the line... the thing has NO smell to it, no rubber roof a heat pump and a host of other improvements (and a $45000 canadian price tag!). My surveyor trailer has been "airing out" for over a year now... still has the new smell (yuck). I really don't like the off gassing that is STILL taking place... :(
 

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I think the trailer suspension is important, especially when pushing the control limits of the rig, and the rubber-sprung independent designs are all virtually the same... Except that Airstream gets them with shocks, and no regular North American suspension of this type has them available.
 

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shineysideup said:
::~snip!~::

Not sure if you have seen the new earthbound trailer yet... This trailer has some big changes in it starting with an aerodynamic front and rear along with lighter weight (compared to conventional trailers) See it at earthboundrv.com I had the pleasure of being in the #4 trailer off the line... the thing has NO smell to it, no rubber roof a heat pump and a host of other improvements (and a $45000 canadian price tag!). My surveyor trailer has been "airing out" for over a year now... still has the new smell (yuck). I really don't like the off gassing that is STILL taking place... :(
These look kinda cool. It'd be nice if maybe they had built-in solar panels on the roof or something...or maybe something that could harness the wind and collect all of that energy while it's being towed and in motion.
 

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So you all seem a little more open minded - much like myself. I have an '08 Sienna LE WITHOUT the "towing package" i.e. oil cooler. I desire to haul a 20/27 or 23/30 foot Trailmanor with dry weights of 2742 and 2915 respectively. These are pop-up trailers, so they tow easier than traditional trailers of equal weight. After scouring all the threads, it seems to me that the only reason my van is only rated to 1250 lbs (and all previous stock Siennas had 3500 ratings going back to 2004, including the 2007 which has my identical engine) is that Toyota is afraid that we'll have the tendency to push the engine to its capacity while towing and because the new engines have some added umph, they decided to add the oil cooler to prevent us from doing damage while taking advantage of the aforementioned "umph." My thoughts are to really take it easy while towing and possibly install an oil temp gauge since it's rather impossible to add an aftermarket oil cooler. How is my thinking? Am I nuts?
 

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goldlimnah said:
So you all seem a little more open minded - much like myself. I have an '08 Sienna LE WITHOUT the "towing package" i.e. oil cooler. I desire to haul a 20/27 or 23/30 foot Trailmanor with dry weights of 2742 and 2915 respectively. These are pop-up trailers, so they tow easier than traditional trailers of equal weight.
Aerodynamic drag is a significant factor, so I agree that the lower body of a pop-up (or the TrailManor folding system) means less sustained load and thus an "easier" tow. I would hesitate to count on this too much, since most pop-ups are still quite wide; my friends towing race cars on flat-deck trailers found that just the trailer fenders sticking out added lots of drag, and adding the car to the trailer didn't make much difference.

goldlimnah said:
After scouring all the threads, it seems to me that the only reason my van is only rated to 1250 lbs (and all previous stock Siennas had 3500 ratings going back to 2004, including the 2007 which has my identical engine) is that Toyota is afraid that we'll have the tendency to push the engine to its capacity while towing and because the new engines have some added umph, they decided to add the oil cooler to prevent us from doing damage while taking advantage of the aforementioned "umph." My thoughts are to really take it easy while towing and possibly install an oil temp gauge since it's rather impossible to add an aftermarket oil cooler. How is my thinking? Am I nuts?
This reasoning makes sense to me.... but you may still be nuts. ;)

Just to be clear... the TrailManor proposal is apparently to exceed the Sienna's limit for towing without the package, but not the limit for towing with one; it is strictly a drivetrain concern, not related to structure or handling (since the package is only the cooler, which affects only the engine). This is cutting it close, since with those dry weights the loaded trailer will be right up to the 3500 lb level, and a family large enough to want that much trailer will likely mean a passenger and in-the-van cargo payload also pushing the GVWR.
 

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Run a quality synthetic oil and enjoy your vacation.


goldlimnah said:
So you all seem a little more open minded - much like myself. I have an '08 Sienna LE WITHOUT the "towing package" i.e. oil cooler. I desire to haul a 20/27 or 23/30 foot Trailmanor with dry weights of 2742 and 2915 respectively. These are pop-up trailers, so they tow easier than traditional trailers of equal weight. After scouring all the threads, it seems to me that the only reason my van is only rated to 1250 lbs (and all previous stock Siennas had 3500 ratings going back to 2004, including the 2007 which has my identical engine) is that Toyota is afraid that we'll have the tendency to push the engine to its capacity while towing and because the new engines have some added umph, they decided to add the oil cooler to prevent us from doing damage while taking advantage of the aforementioned "umph." My thoughts are to really take it easy while towing and possibly install an oil temp gauge since it's rather impossible to add an aftermarket oil cooler. How is my thinking? Am I nuts?
 

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The Sienna can pull a house off it's foundation. We've done some heavy towing (at least 3500) up steep grades where we had to downshift into 1st to hold 25mph. Sienna still runs great, no worries.
 

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goldlimnah said:
So you all seem a little more open minded - much like myself. I have an '08 Sienna LE WITHOUT the "towing package" i.e. oil cooler. I desire to haul a 20/27 or 23/30 foot Trailmanor with dry weights of 2742 and 2915 respectively. These are pop-up trailers, so they tow easier than traditional trailers of equal weight. After scouring all the threads, it seems to me that the only reason my van is only rated to 1250 lbs (and all previous stock Siennas had 3500 ratings going back to 2004, including the 2007 which has my identical engine) is that Toyota is afraid that we'll have the tendency to push the engine to its capacity while towing and because the new engines have some added umph, they decided to add the oil cooler to prevent us from doing damage while taking advantage of the aforementioned "umph." My thoughts are to really take it easy while towing and possibly install an oil temp gauge since it's rather impossible to add an aftermarket oil cooler. How is my thinking? Am I nuts?
I tow a 3200 lbs hybrid with mine and it's exactly the same as yours, it tows great and I anticipate no problems. I met someone at the campground towing a 30 foor airstream w/ a hensley hitch at 9000 lbs, they had towed all over canada for a couple years w/ the setup. I think they had an aux trans cooler and airbags, that's about it.

266 is a lot of horsepower, the wheelbase is long and the track is nice and wide. It's really a nice tow vehicle.
 

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I had emailed Uhaul and asked them if their hitch receiver (the one I bought-78270) was capable of accepting a WD hitch. They said yes, it is capable for WD hitches and that if I installed a WD hitch, my towing capability increases 500 lbs. to 4000 lbs. max. weight. I find that interesting...
 

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That really means the hitch can handle the 4000lbs if you use WDH. The sienna's tow ratings don't change, just the hitch capacity. Toyota doesn't specify a difference. My GVWR on the trailer is almost 3800lbs. We probably approach that when it's fully loaded. We use a Reese Trunion WDH. The Sienna doesn't have a problem with that, in my opinion. I've towed up very steep inclines at campgrounds and the sienna ran up it in second gear at 2000rpm. I was scared of slowing down and dropping it into first gear in case I couldn't get it started up the slope again. Smelled a bit at the top, but no i'll effects. Next time I would start in first gear from the bottom.

jh818 said:
I had emailed Uhaul and asked them if their hitch receiver (the one I bought-78270) was capable of accepting a WD hitch. They said yes, it is capable for WD hitches and that if I installed a WD hitch, my towing capability increases 500 lbs. to 4000 lbs. max. weight. I find that interesting...
 

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tcp said:
That really means the hitch can handle the 4000lbs if you use WDH. The sienna's tow ratings don't change, just the hitch capacity. Toyota doesn't specify a difference.
Thank you, tcp. :)

The hitch receiver from Uhaul is a class 3 so it can handle up to 7500 lbs. Why then would they say you can pull 4000 lbs. with a WD? I looked on their web site and if you enter in your vehicle, it does say 4000 lbs. with WD. Hmmm.....
 

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jh818 said:
The hitch receiver from Uhaul is a class 3 so it can handle up to 7500 lbs.
Class 3 is up to 5000 lb, not 7500 lb, despite the confusing trash published by some companies.

jh818 said:
Why then would they say you can pull 4000 lbs. with a WD?
The hitch classes are just capacity ranges. A specific hitch has a specific capacity, which very often matches the top of one of the ranges, but in many cases does not. If the hitch is rated by its manufacturer for 4000 lb, then that's what can be towed with it.

Building a hitch for a Sienna which is strong enough to handle a 7500 lb trailer would be a waste of money and steel, since that is far beyond the vehicle's capacity. Yes, some people go beyond the ratings by the vehicle manufacturer, but for a mass market product the extra hitch strength would be just pointless.

Most hitches fit within product ranges, with many common components and design features across the range, and the same rated capacity for every model within the range, regardless of whether a load of that capacity would be suitable for the vehicle to which it is attached. For example, if Reese built a "Titan" range hitch by putting thick brackets matched to the Sienna's stock mounting mounts on the end of the usual Titan structural tube, they would probably rate it beyond 10,000 lb (beyond Class 4) - just like the other Titan models - even though towing such a trailer with it might rip the hitch right off of the Sienna... but the hitch itself would handle the load.

jh818 said:
I looked on their web site and if you enter in your vehicle, it does say 4000 lbs. with WD. Hmmm.....
Is that U-Haul's web site? (U-Haul often uses the same part number as the actual manufacturer of the hitch) While U-Haul is very good at running a rental equipment franchise, it is not a reliable source of towing information. The capacities for vehicles which are shown by their website seem to be unrelated to the authoritative ratings by the manufacturers of those vehicles. I can only assume that they calculate capacities in some way which is intended to be the highest value which a potential customer can tow for a short-term rental and not be displeased enough to demand a refund. Personally, I strongly suggest ignoring anything they say. They're a perfectly valid source of rented trailers, and even of the same towing equipment which is available from other retailers, but not of information.
 

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I've been reading this thread with great interest and also own a Canadian 2006 Sienna CE. I just bought a hybrid travel trailer with a UVW rated at 3277 lbs. I had a dealer install a class III Reese hitch with WDH rated at 5000 lbs and a brake controller (reese I believe).

I asked the dealer to look at the Sienna to see if it had the transmission cooler, and they said it did not. I'm pretty sure I read somewhere that all Canadian Sienna's had the tow package, which included the trans. cooler. Could anyone confirm this and tell me what I should be looking for (or pics of your Sienna) to confirm?

I've also heard I should I also drive the vehicle in 4th gear when pulling to trailer? I notice that when I pull the trailer, if I keep it under 100 KM/H, the RPMs stay around 2500. Anything over that (100 km), kicks it into alternating between 2500 and 3500 depending on the terrain. Is this putting excessive strain on the transmission.

The Sienne is rated to pull 3500, so I am under my limit (but not by much)...
 

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Jabba said:
I asked the dealer to look at the Sienna to see if it had the transmission cooler, and they said it did not. I'm pretty sure I read somewhere that all Canadian Sienna's had the tow package, which included the trans. cooler. Could anyone confirm this and tell me what I should be looking for (or pics of your Sienna) to confirm?
This appears to be either yet another reason to distrust dealers and question their competence, or just a miscommunication. The second-generation Sienna does have a transmission oil cooler (with or without the towing package), but it is internal to the radiator. If staff at the dealership don't know that and can't see it in a quick visual examination, they are incompetent; if they mean that there is no separate or additional transmission oil cooler, this may just be a failure to clearly communicate.

I suggest the Sienna Gen-II Towing Capacity topic for an exhaustive discussion of what is in the package; please note that 2006 is the early second-generation version, with the 3MZ-FE engine.

Jabba said:
I've also heard I should I also drive the vehicle in 4th gear when pulling to trailer? I notice that when I pull the trailer, if I keep it under 100 KM/H, the RPMs stay around 2500. Anything over that (100 km), kicks it into alternating between 2500 and 3500 depending on the terrain. Is this putting excessive strain on the transmission.
Excessive shifting up and down - known as "hunting" is both annoying and bad for the transmission, so I consider hunting a valid reason to shift down to the position which is just low enough to stop the hunting.

Jabba said:
The Sienne is rated to pull 3500, so I am under my limit (but not by much)...
Not under by much, but more importantly likely not under at all once fluids and cargo are loaded. In our 17' Boler, we add about 600 lb above unloaded weight to go on a trip, and while we carry some extra junk there are only two of us and I don't think our cargo is extreme. It seems likely to me that Jabba's rig will be slightly over the 3500 lb trailer limit.
 

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ou've got a transmission cooler. Look for two pipes that go into the radiator near the top on the driver's side. They are narrower than the main coolant lines. that's the transmission cooler. If the trailer has an unloaded vehicle weight of 3277lbs, that generally doesn't include fluids (water, propane) as well as things like the battery, awning, AC unit, etc. Check on the label inside one of the cabinets inside for the actual weight with those things installed. It has to be there and if it includes those items, even better.

All that being said, we have a very similar size and weight trailer that has a GVWR of 3750lbs. Guaranteed we had that thing loaded to that weight for our two week jaunt through British Columbia in August. Had the sienna loaded up as well with a roof pod in addition to everything inside. Ours performed extremely well in all the passes and mountain roads. Dropped to second gear on Kootenay pass between Creston and Nelson, BC. Never dropped below 80kms/h (48mph) up rogers pass in 33C heat. Total was 2000kms (1200miles) through some challenging, twisty mountain roads. temperature needle never varied. I ran a quality synthetic oil and emptied/refilled the transmission fluid after the trip. It was still clear and red with no smells. Your sienna will have no issues. Enjoy the camper!

Jabba said:
I've been reading this thread with great interest and also own a Canadian 2006 Sienna CE. I just bought a hybrid travel trailer with a UVW rated at 3277 lbs. I had a dealer install a class III Reese hitch with WDH rated at 5000 lbs and a brake controller (reese I believe).

I asked the dealer to look at the Sienna to see if it had the transmission cooler, and they said it did not. I'm pretty sure I read somewhere that all Canadian Sienna's had the tow package, which included the trans. cooler. Could anyone confirm this and tell me what I should be looking for (or pics of your Sienna) to confirm?

I've also heard I should I also drive the vehicle in 4th gear when pulling to trailer? I notice that when I pull the trailer, if I keep it under 100 KM/H, the RPMs stay around 2500. Anything over that (100 km), kicks it into alternating between 2500 and 3500 depending on the terrain. Is this putting excessive strain on the transmission.

The Sienne is rated to pull 3500, so I am under my limit (but not by much)...
 

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