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Towing experience - Limited AWD

2359 Views 15 Replies 8 Participants Last post by  jseyfert3
tommyhp2 said:
PS: Has anyone towed 3500 lbs in the new hybrid AWD? How does it feel? The old ICE AWD can't tow that much, IIRC, that's why we got the FWD instead.

We have a Limited AWD and recently went on a trip to Myrtle Beach from northern WV. I installed the Eco Hitch and hooked up our 12x6' aluminum trailer (1000 lbs), loaded it with our golf cart (1200 lbs), full coolers, storage tubs packed with equipment, tools and camping stuff. the van was then loaded with four adults, two teenagers and luggage. Pretty sure we were at or a little above max GCVWR.

I just sold my '17 Ram 2500 Mega Cab diesel as our camper is now in its' permanent home at the beach and just didn't need that beast anymore. We used to live near Rapid City, SD and have driven though the Rockies plenty of times: Pikes Peak, Aspen, our favorite Dillon (that Dam town), etc.

  • Our route took us through and over some taxing areas for any tow vehicle; if anyone has driven from Mt. Airy, NC through Mt. Hope, WV, you know what I'm talking about.
  • The rear of the van sagged noticeably, but handled, braked, and performed well overall.
  • Our avg. highway speed was 65-75mph which the van was able to maintain even up the longer grades.
  • The engine noise was very noticeable as it was well into the PWR zone up hill and when the regen quickly maxed out going down. (this is all controlled by the ECU to maintain within operating limits, so I wasn't really concerned)
  • I think if I were to try this same setup on the Eisenhower Tunnels Approach, I could maintain 55-60mph without too much drama. Without trailer brakes, I'd reduce speed considerably on the decent though!
- I purposely did not concern myself with economy on this trip as I wanted to compare the van with our V8 Durango which normally makes this trip. So, an equal time was my goal. - easily met.
  • The Durango averaged this trip (loaded/towing) at about 13mpg.
  • The Sienna made it to at 21mpg and from at 21.5mpg which was somewhat surprising being our home is 1200' higher than MB.

Overall, I'm pleased with the Sienna's towing, but will 100% be installing airbags in the rear springs before our next trip down.

- Do note that if you do tow much, you need to follow a more frequent maintenance schedule. (Eng. oil, front/rear transaxle fluid, etc.)

Happy towing,
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I had a WD hitch for a couple of my trucks. Yes, they do level the vehicle, but puts more stress on the receiver attach points and hangs down an additional 3-4 inches. I think the rear springs are too soft to safely use a WD hitch as the amount of weight you would need to transfer to the front axle to ride level would severely affect handling.
And if you're like me and load your trailer close to max, when you have a WD hitch some of the vehicle weight is transferred to the trailer also...
Well, sort of. I was going to say this was wrong, then stopped and did the math before answering. Turns out the answer is yeah, you’re increasing the load on the trailer axle over a trailer without WD, but this extra load is probably considerably less than the trailer tongue weight if you set up the WD hitch correctly.

See my attached math, including free body diagrams. Pardon my sloppy handwriting and somewhat disorganized work, it’s been a while since I took Statics in college and I had to clear some cobwebs from my brain to do this. On my example I used a 4000 lb towing vehicle that has 2000 lbs on each axle (no trailer), with a 1000 lb trailer set up with 10% (100 lbs) of tongue weight. For distances I used 10’ from the trailer axle to the hitch ball, 5’ from ball to rear axle, and a 15’ wheelbase on the tow vehicle. I used the assumption of maximum recommended weight distribution, which is making the front axle of the tow vehicle weigh the same with the trailer as it was with the vehicle unloaded.

With these weights and distances, a vehicle towing a trailer with no weight distribution would have 900 lbs on the trailer axle, 2133 lbs on the towing vehicle rear axle and 1967 lbs on the front axle.

Using weight distribution to bring the front axle back to 2000 lbs, the trailer axle would be 933 lbs and the rear axle of the towing vehicle would be 2067 lbs. So the towing vehicle would not be level, since it has extra load in the rear, but as mentioned you do NOT want to use WD to bring the vehicle completely level, since to do so would load the front axle more that it is loaded with no trailer.

You can then use airbags or stiffer rear springs to keep the rear of the towing vehicle closer to the non-trailer ride height. But the WD hitch would help considerably on its own.

You would have to severely improperly overuse WD to actually make the rear of the vehicle lighter than it is without a trailer.

Summary is that the appropriate use of a WD hitch will greatly help with maintaining tow vehicle angle, but not completely eliminate it, you need airbags or different springs for that. But the primary purpose of a WD hitch is to put the weight back onto the front axle to maintain traction and steering, and doing so will add some weight to the trailer axle but not anything that’s concerning, at least in this example.

As @floridanative said, it doesn’t matter how soft the springs are, using WD will still help considerably, because you will always have less weight on the rear axle with a WD setup than without. Spring stiffness has nothing to do with the weight that are applied to the axles, only the vehicle sag. And if you have half the weight difference on the rear axle with linear springs, you have half the sag (assuming the WD is adjusted to keep the front axle at the weight it was without a trailer).

If anyone has any questions on my math, let me know. Statics is fun, and pretty straightforward. I started doing this and initially couldn’t remember how to do it, before my teachers voice came into my head, repeating what he drilled into our brains during Statics: “the sum of the forces in the Y direction equals zero. The sum of the forces in the X direction equals zero. The sum of the forces in the Z direction equals zero. The sum of the moments about any point equals zero.” After I remembered that it was super easy, especially as we only have 1 direction the forces are acting in for this calculation. Dynamics is where it gets really interesting though, because for accelerating objects the sum of the forces and/or moments does not equal zero…luckily we don’t need to worry about that here. 😂
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I guess it depends how much you are towing. I’m not saying airbags are bad by any means. I’m saying the best setup would be a WD hitch and airbags, since airbags will only correct vehicle sag. Airbags don’t transfer any weight so even though the van may ride close to the non trailer ride height, the front axle will still have less weight that it did before towing. A WD hitch is the only way to keep this from happening.

To be fair, I haven’t towed much with a Sienna yet. Just Uhaul trailers when I moved. I have towed many thousands of miles with a 2013 Honda Pilot and a camper weighing approximately what it did (~4500 lbs), and a decent amount with a 2020 Silverado 1500 and a camper weighing considerably more than it did (~8500 lbs). Neither had airbags but both had WD hitches.

I thought the reason for leveling a trailer was for ground clearance, and on multi-axle trailers to keep from loading the trailer suspension poorly. And on the towing vehicle side a massively unlevel vehicle was a sign of overloading and/or the need for WD. Why would not being in the same plane cause stability issues?

As another point, the 4th gen Sienna manual says to use a sway control device on trailers over 2000 lbs, and since sway control is most commonly (though not exclusively) combined with WD, may as well just use WD when towing heavy trailers with the Sienna. It’s definitely going to help sag a lot, plus as mentioned will keep the front axle loaded properly, which will also help vehicle stability and steering.

EDIT: I guess my main points are that you said WD will overload the front axle and trailer. It won’t, if properly setup. And you said WD won’t help with sag. It will most certainly help with sag, without overloading front or trailer axle. It won’t completely eliminate it without overloading the front axle, yes. I agree with you there.

It’s not either air bags (or other suspension help) or WDH… the correct answer is “both”. Just stiffening the suspension without WDH is not going to be as good as a stiffer suspension with WDH.

Yes, exactly. Well stated.
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