Model X Travel Trailer Consumption Analysis

[idoco]

Yes, I got that. Sorry, I didn't phrase it well. What I meant was "is it yours that you'll be hauling across the country?" And congratulations. I definitely have some camper envy. It's going to be gorgeous!

Oops...yes it ours. We actually own it as of ten days ago. Headed out to actually take possession. One week to drive out from the east coast. Then we'll meander back over the next four weeks.

 

[aesculus]

I've got some data from two trips I recently took with rentals.

I've got @noahsw data and will be pouring over it after I get 3.1 out the door, hopefully this week.

 

[JimVandegriff]

I've got some data from two trips I recently took with rentals.
We just pulled the trigger on a Winnebago Minnie Drop 170K! http://www.tacomarv.com/default.asp...Year&d=D&floorplan=bunkhouse&fr=xAllInventory

Beautiful Minnie Winnie! Looking forward to hearing about your adventures. Jim

 

[ecarfan]

It looks like the Bowlus Road Chief can get by with a pf = 10, Airstream = 20 and some other users have reported they needed a pf=30 to match the consumption on less efficient trailers.

I’ve changed my EVTO profile to a Power Factor setting of 20 (I was using 10) and I will report back after my next towing trip with my 17ft Alto, which won’t be until the end of May at the earliest (having solar and new batteries installed in my trailer right now).

I can probably help you out with some Bowlus data in a couple weeks since we're towing one back to the East Coast from Las Vegas with our X90D. I'm logging it via TeslaFi so should have decent data.

Very cool, I look forward to your report!

 

[ecarfan]

2013 Jayco Jay flight SLX 185RB
(https://www.jayco.com/files/downloads/prod_brochure_filename_193.pdf). 2800 dry weight. Slight upwards slope on the trailer nose, otherwise not aerodynamic at all. I was mostly driving along I-5 in Washington State. Range was a little better than half (620 Wh/mi) in ideal conditions going 55mph (no wind, no elevation change, ~50 degree temp). Standard ball hitch without brake controller worked fine. Only felt a little sway when giant semis passed me

I was interested to read about your towing that 20 ft, 3000+ lbs trailer (when loaded with water and other stuff) with no brake controller and I assume no weight distribution hitch (?) based on your use of the phrase “standard ball hitch”. I searched the web to see what kind of brakes that trailer has and found “electric drum” on this page Full Specs for 2015 Jayco Jay Flight Swift SLX 185RB RVs | RVUSA.com . Were they “surge” type brakes that automatically activated at a certain deceleration level?

WA state law appears to require trailer brakes for trailers over 3000 lbs gross weight or when gross weight of the trailer exceeds 40% of the weight of the tow vehicle (a Model X with two adults plus their stuff would be approaching 6000 lbs) based on my reading of this page RCW 46.37.340: Braking equipment required.

Your energy usage on I5 in Washington is roughly similar to what I experienced towing my 17 ft 1600 lb Alto on that highway in late February but I had significantly colder average temps, around 35-45F.

 

[noahsw]

WA state law appears to require trailer brakes for trailers over 3000 lbs gross weight

Yes, I was made aware of this law when I bought my trailer. The two rentals never mentioned this!

 

[KJD]

Any thoughts on how the Airstream Basecamp energy consumption would compare with towing the Sport model?

Same question on the Airstream Nest.

 

[idoco]

Early estimates from our return trip pulling the Bowlus. I'll eventually post the TeslaFi numbers.

Model X90D pulling trailer 485Wh/mi (early estimate for flat and 55mph)
Estimated range pulling trailer 170 miles

See below for more details:
Tin Poodle: We haven't run out of gas...yet...

 

[ecarfan]

Any thoughts on how the Airstream Basecamp energy consumption would compare with towing the Sport model?

Same question on the Airstream Nest.

It’s primarily about the frontal area of the trailer and the shape, the weight of the trailer is of little influence when towing on level ground.

Airstream Sport frontal area: 96” x 108” (including AC unit on roof) and it has fully radiused corners which reduces drag.

Airstream Basecamp frontal area: 84” x 105” . The Basecamp does not have radiused corners like the Sport, but it has less frontal area and the front is curved along the vertical axis, which is helpful.

The Airstream Nest frontal area: 85” x 114” (including AC unit on roof). It has fully radiused corners but they are a sharper radius than the Sport.

I suspect energy usage will be similar for those three trailers. So far I have not seen anyone post Wh/mi numbers for the Basecamp or Nest.

If you are in the market for a trailer to tow with your X, consider the Safari Condo Alto F21114 and F1743 Towing with your X? New Alto model: 21 ft lightweight camper trailer

Alto F-series frontal area : 86” x 96”

So it has the smallest frontal area compared to those three Airstreams, and it weighs far less. It has a significantly curved front end along the horizontal axis, but no radiused corners. When towing my F1743 I can achieve under 500Wh/mi at 55mph, level road, no rain or headwinds, 70F air temp.

 

[idoco]

Cool. If you feel inclined I would love to see your logs. You can send them to [email protected].

Check your email.

Some analysis here: Tin Poodle: Final stats...and stats...and more stats...

 

[ecarfan]

@idoco thanks for your latest blog post at Tin Poodle. You wrote:
——————————
Best "MPG" 369 wH/mile (East side of continental divide)
——————————

What’s that a significant elevation loss?

You are getting great Wh/mi numbers with your Bowlus. Do you have any long distance trips planned for this summer?

 

[JimVandegriff]

Quick data point from this past week: Model X 90D pulling 22 ft Airstream Bambi Sport trailer (about 4000 lbs) with Draw-tite hitch having replaced the Bowsal hitch, 260.3 miles travelled with the trailer, 156 kWh used, 599 Wh/mi. Terrain was rolling hills, no rain, 0 net elevation gain or loss. We went up the coast of California to the Humbug Mountain state park in Oregon, camped for a week, and came home. It was extremely relaxing and fun. We charged at the Crescent City supercharger each way, and at the campsite with the Tesla 14-50 adapter used with the campsite electrical box. Talked to lots of folks about Tesla at the campsite (including some brand new model 3 owners). Thoroughly enjoyable trip. It is clear to us that electric vehicle consciousness is beginning to permeate the culture (much more awareness and acceptance of electric powered vehicles among the other campers.) We are thinking of heading to Lassen in June.

 

[idoco]

@idoco thanks for your latest blog post at Tin Poodle. You wrote:
——————————
Best "MPG" 369 wH/mile (East side of continental divide)
——————————

What’s that a significant elevation loss?

You are getting great Wh/mi numbers with your Bowlus. Do you have any long distance trips planned for this summer?

Over 3000 feet loss. Plus went slower because of construction, traffic, and downhill switch back curves.

Planning on short trips (< 600 miles) remainder of summer. No big trips until next year.

 

[KJD]

Quick data point from this past week: Model X 90D pulling 22 ft Airstream Bambi Sport trailer (about 4000 lbs) with Draw-tite hitch having replaced the Bowsal hitch, 260.3 miles travelled with the trailer, 156 kWh used, 599 Wh/mi. Terrain was rolling hills, no rain, 0 net elevation gain or loss. We went up the coast of California to the Humbug Mountain state park in Oregon, camped for a week, and came home. It was extremely relaxing and fun. We charged at the Crescent City supercharger each way, and at the campsite with the Tesla 14-50 adapter used with the campsite electrical box. Talked to lots of folks about Tesla at the campsite (including some brand new model 3 owners). Thoroughly enjoyable trip. It is clear to us that electric vehicle consciousness is beginning to permeate the culture (much more awareness and acceptance of electric powered vehicles among the other campers.) We are thinking of heading to Lassen in June.

Jim thank you for the stats. What was your average speed on this one ?

 

[JimVandegriff]

Jim thank you for the stats. What was your average speed on this one ?

Avg speed generally in the 50-55 mph range. We went a bit slower on the Newton P. Drury scenic parkway through Prairie Creek Redwoods state park (for the fantastic view of the old growth redwoods through the windshield).

 

[AltoGrayhound]

Bonjour everybody from Quebec home of my AltoF1743 ! I have travelled 3 times in June. 665mi + 134mi + 436mi. Average 572wh/mi + 619wh/mi and 634wh/mi. It is in line with the numbers exposed by you all. I have peak at 877wh/mi with front wind and heavy rain and low of 564wh/mi for a 224 mile trip with no wind. All at 55mph. As posted earlier, I want to add a box between the two. I found a program in Europe where you can analyse the air drag of a profile. It gives a video of 10 to 60 seconds. See the screen shot. I started a prototype box with coroplast see picture attached. First step to try it on the road see if it is worth the investment to do it in aluminium. What % will be the increase if there is one. Appreciate your input.

 

[AltoGrayhound]

ohm

Bonjour everybody from Quebec home of my AltoF1743 ! I have travelled 3 times in June. 665mi + 134mi + 436mi. Average 572wh/mi + 619wh/mi and 634wh/mi. It is in line with the numbers exposed by you all. I have peak at 877wh/mi with front wind and heavy rain and low of 564wh/mi for a 224 mile trip with no wind. All at 55mph. As posted earlier, I want to add a box between the two. I found a program in Europe where you can analyse the air drag of a profile. It gives a video of 10 to 60 seconds. See the screen shot. I started a prototype box with coroplast see picture attached. First step to try it on the road see if it is worth the investment to do it in aluminium. What % will be the increase if there is one. Appreciate your input.

@om

@idoco thanks for your latest blog post at Tin Poodle. You wrote:
——————————
Best "MPG" 369 wH/mile (East side of continental divide)
——————————

What’s that a significant elevation loss?

You are getting great Wh/mi numbers with your Bowlus. Do you have any long distance trips planned for this summer?

Bonjour Ecarfan. I put a post on this thread. not if you saw it.

 

[AltoGrayhound]

This informative document was shared with me on the Airstream Forums in response to some questions about the Model X -- travel trailer linkage distance. It includes much more information that is applicable to our topic, and I found it fascinating.

Regarding the linkage question, the yaw angle (angle of air travel across the roadway) changes the coefficient of drag significantly. This situation is exacerbated by hard edges on the trailer and by the tow vehicle-trailer gap. See the following diagram (apologies about the resolution) for the effects at yaw angles up to 20° (source: Hammache, Michaelian, Browand). This provides support for radius edges like on the Airstream and also minimization of the gap between the tow vehicle and travel trailer.
View attachment 209358

Bonjour Ohmman, put a new post on the thread not sure if you saw it. appreciate your input. AltoGrayhound

 

[j-rho]

Something to consider, there may be greater potential gains by attaching something to the back/trailing portion of the trailer, than between car and trailer. I'd interpret the steady red color above the car and between car and trailer as attached flow, which is good - it starts to get bad at the top of the trailer, and the big maelstrom back behind the trailer is what's most costly.
Maybe do some experiments extending the trailing edge out more, see how it looks. You could probably draw something that kept flow attached all the way to the rear, though it would be too long/unwieldy to be practical in use.

 

[AltoGrayhound]

Thank you j-rho for your follow-up. For the back of the trailer I was thinking of Vortex generator like AirTab. Any info on efficiency and how to use it?