Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Towing travel trailer with Model Y

Webeevdrivers

Active Member
Jan 2, 2017
2,351
4,105
Canada
Did you actually watch the video? It’s only 12 minutes, and the first two minutes are unnecessary for anyone familiar with the Model 3. Skip that and get to the part where Andy Thomson of Can-Am RV (in London, Ontario, Canada) talks about towing with a Tesla. That guy is extremely knowledgeable and experienced.

The Model 3 shown towing in that video has a hitch installed by Can-Am. It is nothing like the typical 2” hitch Tesla installs on the X and Y or that I had installed on my 3 for a bike rack. The hitch shown in the video is attached to the car frame at multiple points and can be seen in the trunk subfloor area. It is also a weight distribution hitch. With that hitch the 3 can easily and safely tow the 6,000 lb Airstream shown.

The only discussion of range in that video is Thomson saying that while towing that trailer the 3 has a range of about a hundred miles. When I tow my Alto with my X at 55mph on a level, dry road with no headwind my range is about 140 miles max. I typically drive for 2 to 2 1/2 hours, meaning about 120 miles, and then stop to charge. It’s nice to take a break from driving, have a snack and a bathroom break and maybe a quick snooze (because I have my kitchen and bathroom and bedroom with me!).

Other than that the video does not discuss range or long distance travel. The guy who made that video is not a Tesla or EV owner and may not fully appreciate how important fast charging and the Supercharger network is. It’s hard to grasp until you have owned a Tesla and experienced it on a long trip. Thomson mentions “charging for an hour” and again he doesn’t understand that you never spend that much time at Supercharger. 30 to 40 minutes max is what it takes. I almost never charge to 100% while towing; typically 90 to 95% and of course I don’t start from zero.
The first link I posted, A “Safari Condo” is not an apartment in the Serengeti… , on that page right after the section “Is the teardrop trailer shape an advantage” (answer; no) is a section titled ”Why I chose the fixed roof Alto”.

Here is what I wrote:

Is a “teardrop” trailer shape an advantage?​

Safari Condo claims “…the aerodynamic shape of the Alto, developed in a virtual wind tunnel, creates 75% less aerodynamic drag than a traditional travel trailer. This factor, along with its lightweight, makes the Alto readily towable by most compact cars and small SUVs.” And at about 1,800 lbs, the 17 ft Alto is definitely a lightweight compared to other trailers in its size range: the Airstream Sport 16 weighs nearly 2,900 lbs. Many Alto owners tow with 6-cylinder Subarus and other small vehicles.

My conclusion was that while the retractable roof Alto certainly has less drag than a “traditional” box-shaped trailer, and the low weight does make it towable by smaller vehicles with more modest engines than a Ford F-250 for example, the sharply sloping rear roofline is probably not an advantage. An engineer with aerodynamic experience informed me that air flowing across the trailer roof peak would tend to separate from the roof as it sloped sharply downwards and then would interact with the air coming off the sidewalls, creating turbulence and acting like “twin parachutes” that would increase the energy consumption of the tow vehicle compared to a more gradually sloping roof. A Canadian RV dealership with extensive experience towing a variety of trailers, including every version of the Alto, said that the R series trailers offered no noticeable energy savings compared to the 95” tall F1743 fixed roof version. It was also clear to me that the Model X was a suitable tow vehicle, since Canadian Model X owners Rolf and Silke Sommerfeld were towing their Alto across Canada and back!

Why I chose the fixed roof Alto​

So I turned my attention to the F1743 model, which still features a generous amount of window area all around while offering more storage and most significantly, an enclosed bathroom. As I compared it to other trailers on the market in the 15 to 19 ft size range, I realized that the 17 ft Alto F1743 had numerous advantages. In a very compact size it provides a queen size sleeping area aft that can be left made up all the time if desired because there is also a very usable two-person dinette table forward which converts to a single bed as needed (with just the two of us, we’ve never had the need for that). The kitchen counter space includes a sink and two-burner stove, lots of storage below and more storage above along with an optional microwave. The 12V 4.3 cu ft refrigerator is positioned below a generously-sized clothes closet. The compact bathroom has a toilet, shower and a small cabinet. Additional storage is available below the sleeping area and dinette seats. Exterior hatches provide easy access to the same storage areas.

Just as importantly, it is clearly made with care and to a high standard, with a very contemporary style. Lightweight materials are used throughout; the trailer frame, exterior walls, and interior walls are all aluminum, as is the floor. There is no wood anywhere; composites are used extensively and the only steel employed is in the axle, suspension components, and tongue. LED lighting is used throughout. The double-wall acrylic windows, made in the Netherlands, include built in adjustable screens and shades. The fresh, grey, and black water waste tanks are located beneath the floor for a low center of gravity. A small exterior hatch next to the freshwater hose connection conceals a shower head and hot/cold water controls for outdoor showering.

The Alto F1743 base dry weight of 1742 lbs is astonishingly light (and slightly lighter than the retractable roof Alto) yet Alto owners with years of towing experience report that the trailer design holds up very well over tens of thousands of miles of travel. In comparison, the 16 ft Airstream Base Camp weighs almost 2,600 lbs, lacks a permanent dinette area, and costs 15% more. The more traditional looking 16 ft Airstream Sport weighs nearly 2,900 lbs and offers a twin size bed (48” wide) instead of the queen size (60” wide) that is standard in the Alto, yet costs about 60% more.

The new 16.6 ft Airstream Nest caught my eye with its modern style, rounded corners, queen-sized sleeping area, and sink in the bathroom (only available in the Alto by special order). But it lacks a permanent dinette table, costs 60% more than the Alto F1743, and despite featuring a fiberglass body shell weighs a shocking 3,400 lbs! How is that possible; are the countertops made of concrete?

This is what we intend to tow. Opinions on its shape? Aerodynamics etc. I know nothing about this stuff.

D863AD10-7AD0-4E03-B4A1-6A42015664B6.jpeg
 

Zoomit

Active Member
Sep 1, 2015
2,245
4,276
SoCal
Opinions on its shape? Aerodynamics etc. I know nothing about this stuff.
I see these trailers and know there's no real aero engineering being applied to them. We're currently in the 1950's era of car design with respect to trailers--designers are drawing something that looks aerodynamic (teardrop) but isn't really. Sure it's better than a box, but as soon as the flow separates from the rear surface near the top, the remaining "swoopy" shape is just for looks, not function.

The TAB 400 trailer as shown:

Good:
  • Curved front and top surface
  • Wheels tucked inside and not protruding (much)
  • No large A/C or vent hood on top
  • No large roll-up awning on side
  • Blue box in front is good use of space that has no detrimental effect on aero

Bad
  • Flat sides with sharp corners meeting at the front, top and rear
  • Protruding blue trim on edge acts as a fence
  • Rear interior room is cramped to maintain the (basically useless) teardrop shape at far rear
This trailer has near "state of the art" aero, which is to say it's pretty bad, but better than a box. There's a lot of room in the RV trailer industry to improve.
 

ecarfan

Well-Known Member
Sep 21, 2013
19,350
14,016
West Vancouver, British Columbia
Rear interior room is cramped to maintain the (basically useless) teardrop shape at far rear
Agreed, and that is the aspect of the “teardrop” shape that I wish trailer designers would move past! It offers no benefit at all, only a long list of negatives.

Airstreams may be very heavy for their volume compared to an Alto but they do have nicely radiused corners all around and that is a good thing. If Airstream would pay more attention to weight and upgrade their overall quality I would be interested.
 

Zoomit

Active Member
Sep 1, 2015
2,245
4,276
SoCal
Agreed, and that is the aspect of the “teardrop” shape that I wish trailer designers would move past! It offers no benefit at all, only a long list of negatives.
To emphasize this more, here's a rough picture of what's going on with the airflow. It separates somewhere around 1/3 from max height and forms a wake behind the trailer full of turbulent air. This causes high base drag and is bad. The second picture has a modified TAB 400 with a raised back. The raised back reduces the adverse pressure gradient, due to the shallower slope, and allows the airflow to remain attached both further back and lower. Both the TAB 400 and a modified TAB 400 would basically have the same drag, but the modified version would have more useable rear interior space. This clipped teardrop shape is similar to the Alto F1743 pictured at bottom.
Screen Shot 2021-07-03 at 2.32.03 PM.png
 
Last edited:

DayTrippin

Member
Apr 30, 2021
710
675
Jax
It is basically like a Kamm tail design that way. For those who are unfamiliar with Wunibald Kamm, he was an amazing engineer and inducted into the Automotive Hall of Fame. There were a lot of cars that incorporated his designs principles.

There is a recent SAE paper on "Streamlined Tails - The Effects of Truncation on Aerodynamic Drag". Here is the abstract. It will help with the overall concept.

Significant aerodynamic drag reduction is obtained on a bluff body by tapering the rear body. In the 1930’s it was found that a practical low drag car body could be achieved by cutting off the tail of a streamlined shape. The rear end of a car with a truncated tail is commonly referred to as a Kamm back. It has often been interpreted as implying that the drag of this type of body is almost the same as that for a fully streamlined shape. From a review of the limited research into truncated streamlined tails it is shown in this paper that, while true for some near axisymmetric bodies, it is not the case for many more car-like shapes. For these shapes the drag reduction from an elongated tail varies almost linearly with the reduction in cross section area. A CFD simulation to determine the drag reduction from a truncated streamlined tail of variable length on the simple Windsor Body is shown by way of confirmation.
 
  • Like
Reactions: Zoomit

Webeevdrivers

Active Member
Jan 2, 2017
2,351
4,105
Canada
Thank you for the opinions. We like the trailer and the layout and it should be a good fit for us. We have been RVing for 30 years but we have changed how we camp and small is important now. Ferries, small sites, and towing with a Y or an X is in our future. We have an x on order but are leaning towards the Y now.

Thanks again.
 

Zoomit

Active Member
Sep 1, 2015
2,245
4,276
SoCal
It is basically like a Kamm tail design that way.
Yes-- A Kammback or Kamm tail is a truncated teardrop, but that assumes the teardrop was an optimized shape with minimal separation. The typical "teardrop" trailer shape is one-sided and has an extreme slope at the rear leading to separation. It is not an optimum shape to form the basis for a Kammback.

Here's an obviously unrealistic version of a more optimized teardrop. Cut that tail off, and you get the modified version I showed above.

Screen Shot 2021-07-03 at 3.49.08 PM.png



One more question. Would adding vortex generators help. Those little plastic thingies?

Maybe a little, though not worth the pain to size and locate correctly and install. You can't just slap them on and expect a benefit. To be effective, VGs need to be designed for the shape and vehicle speed. If too big, they just cause separation further forward and higher up the body, leading to increased drag. If too small or too far back, they do nothing.
 
Last edited:

Webeevdrivers

Active Member
Jan 2, 2017
2,351
4,105
Canada
Yes-- A Kammback or Kamm tail is a truncated teardrop, but that assumes the teardrop was an optimized shape with minimal separation. The typical "teardrop" trailer shape is one-sided and has an extreme slope at the rear leading to separation. It is not an optimum shape to form the basis for a Kammback.

Here's an obviously unrealistic version of a more optimized teardrop. Cut that tail off, and you get the modified version I showed above.

View attachment 681193




Maybe a little, though not worth the pain to size and locate correctly and install. You can't just slap them on and expect a benefit. To be effective, VGs need to be designed for the shape and vehicle speed. If too big, they just cause separation further forward and higher up the body, leading to increased drag. If too small or too far back, they do nothing.

Thankyou. We live in BC and we’ll be doing most of our camping here. Speed limits are rarely over 90 KMH and the reality is with all the small towns slowing us down to 50 KMH. I doubt the average speed will be much over 70 KMH. Just a guess but at those speeds aerodynamics plays less of a factor. Talking to a Y driver in the next town over with a small teardrop, he says he commonly sees consumption rates of 350 watts per km. It will be interesting to see how it works out. We have a 6 week trip planned out thru the interior following the old gold towns, on the fairy over to Vancouver island, up the island, on the ferry again on the inside passage to prince Rupert and then tour the caribou back towards the Okanagan. 3400 km and about 850 of that is floating. :). I think our longest day is 173 kilometres. Can’t wait. Unfortunately it will have to wait until next May.

Thanks again.
 

ecarfan

Well-Known Member
Sep 21, 2013
19,350
14,016
West Vancouver, British Columbia
We have a 6 week trip planned out thru the interior following the old gold towns, on the fairy over to Vancouver island, up the island, on the ferry again on the inside passage to prince Rupert and then tour the caribou back towards the Okanagan. 3400 km and about 850 of that is floating. :). I think our longest day is 173 kilometres.
Your trip sounds great! The low average speeds will indeed help you a great deal. You may not be able to do 173km without charging once so check out PlugShare for charging options enroute.

I will be interested to hear from you about your Wh/km numbers after your trip. I recently moved to Vancouver and have two trailer trips planned over the next two months though they are all short; one to Whistler, one to Lund on the Sunshine Coast and one to Ucluelet on the west coast of Vancouver Island.

EV chargers are scarce on the Sunshine Coast. To do the 157km from Langdale to Lund I plan to stop and use the Tesla destination chargers at the Pender Harbor Hotel in Madeira Park. If they weren’t there I would have to make an overnight stop to charge before Lund.
 

Webeevdrivers

Active Member
Jan 2, 2017
2,351
4,105
Canada
Your trip sounds great! The low average speeds will indeed help you a great deal. You may not be able to do 173km without charging once so check out PlugShare for charging options enroute.

I will be interested to hear from you about your Wh/km numbers after your trip. I recently moved to Vancouver and have two trailer trips planned over the next two months though they are all short; one to Whistler, one to Lund on the Sunshine Coast and one to Ucluelet on the west coast of Vancouver Island.

EV chargers are scarce on the Sunshine Coast. To do the 157km from Langdale to Lund I plan to stop and use the Tesla destination chargers at the Pender Harbor Hotel in Madeira Park. If they weren’t there I would have to make an overnight stop to charge before Lund.
Ucluelet is gorgeous. You’ll love it.

I think 173 kilometres should be doable with no issues. But there are a few BC hydro and Fortis stations along the way and two of them are trailer friendly. We have a Chademo adapter. We’ll report back with results next May. Can’t wait.
 

Spenny818

Member
Apr 26, 2012
114
84
Peterborough, ON
This is what we intend to tow. Opinions on its shape? Aerodynamics etc. I know nothing about this stuff.

View attachment 681134
My parents just purchased a 2018 TAB 400 they intend to tow with their Y. I am heading up there this weekend to help with getting everything setup for their maiden voyage, and will post photos and consumption stats for you afterwards.
 

Webeevdrivers

Active Member
Jan 2, 2017
2,351
4,105
Canada
My parents just purchased a 2018 TAB 400 they intend to tow with their Y. I am heading up there this weekend to help with getting everything setup for their maiden voyage, and will post photos and consumption stats for you afterwards.

Looking forward to your results. I suspect our speed limits are a little slower than Ontario’s if my memory serves me correctly. (Lived there for a few years). Just a heads up. The [email protected] hitch weight gets lighter the more water you put in it. Tank is ever so slightly behind the axle. Don’t go to light on the hitch weight or it will get squirrelly. Take pictures if you can. Bring extra links for the safety chains in case they are tight.

Thank you in advance.

John.
 
  • Helpful
Reactions: SmartElectric

Flybuddy

Member
Jul 12, 2020
344
349
Fort Myers FL
Has anyone tried towing a Jayco SLX7 174BH. Looks like it's right at the edge of capacity and/or over if you load it to it's full rated capacity.
I had towed a Jayco 19XUD with the Y. The Y has plenty of power and weight doesn't seem to impact the wh/mi once you're moving. Aerodynamics play a bigger role as you can see the affect on wh/mi when towing into a headwind vs a tailwind. The one issue I had with the 19XUD was the actual tongue weight (vs what was listed by Jayco). I wound up going to a Retro 135 which is 1000 lbs lighter and 100 lbs less tongue weight. Interestingly, given the similar aerodynamic footprint (similar frontal area), the wh/mi is not that much different.
 

Attachments

  • IMG_7937.JPG
    IMG_7937.JPG
    463.7 KB · Views: 21
  • Like
Reactions: SmartElectric

Flybuddy

Member
Jul 12, 2020
344
349
Fort Myers FL
What was your Wh/mi, and at what speed? Thanks.
Sorry, that was a year back and I'd have to dig through a lot of old posts to find the numbers, I can tell you that I do remember that it was less than 50 wh/mi between the 2 campers. I also remember calculating that max range would be right around 100 miles (no reserve) for the Jayco 19XUD and about 120 for the Retro 135. Speeds between 55 and 60 for both.
 

Araman0

Member
Apr 18, 2018
298
460
Seattle
A couple tricks I use for lowering our tongue weight:
  1. Replace the factory lead acid batteries with a lithium phosphate or lithium iron battery. This can be expensive, but will shave off 50lb or more from the tongue.
  2. Go small with the propane tanks. If your unit comes with two tanks, obviously go down to one. We also ditch our standard 5 gallon tank for a 1 gallon tank during Summer months when heating isn't a factor and we just want to cook or have hot water. The 1 gallon tank easily lasts a long weekend and plenty more for us. We also store the tank inside the trailer over the axis or near the rear when moving, but be careful if your tongue weight starts to go below 10% of the trailer weight as the trailer can become unstable.
  3. Sometimes I wonder about replacing our power jack with a manual crank jack. This would likely reduce weight and honestly a crank jack is just fine with us.
 
  • Informative
Reactions: DavidAsheville

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top