Model X Travel Trailer Consumption Analysis

[ecarfan]

Energy usage data from today, towing my 2300 lbs (loaded) Safari Condo Alto F1743 trailer, on Hwy 101 in California;, 620 Wh/mi for Myers Flat to Ukiah (lots of hills), 509 for Ukiah to Petaluma (net elevation loss) and 575 for Petaluma to San Mateo. 55mph most of the time, sometimes slower. Temps ranged from 58 in the morning to 88 mid-day.

This was the return leg of a 10 day trip to the Humboldt Redwoods State Park area in Northern California.

 

[dmizock]

Does anyone have experience with, or is familiar with the Forest River R-Pod? We really love the layout of the the newer 2017/2018 179, and would love to know how it might do behind an X100D. Thanks.

 

[ecarfan]

anyone have experience with, or is familiar with the Forest River R-Pod? We really love the layout of the the newer 2017/2018 179, and would love to know how it might do behind an X100D.

I have not seen anyone post on TMC about towing that specific trailer.

It is about a foot taller and almost a foot wider than my 17ft Safari Condo Alto F1743, 3 ft longer, and over 1,000 lbs heavier. The overall shape is similar.

I can only speculate that it will require “significantly” more energy to tow than my trailer. How much more I can’t say. But it will be measurable, it won’t be trivial.

 

[JimVandegriff]

Does anyone have experience with, or is familiar with the Forest River R-Pod? We really love the layout of the the newer 2017/2018 179, and would love to know how it might do behind an X100D. Thanks.

Illijana and I were considering R-Pods, including the 179, when first looking for a trailer. We liked them, but decided to go for more room and a full bathroom. The R-Pods have some nice layouts, attractive price points, and seem very popular (which I translate to mean they have features that people like using.) I haven't towed one with my X though. Let us know what you decide. Jim

 

[Emersoj2]

It's worth noting that you're not likely to be fully drained on your existing pack and that most RV stops are generally longer than 12 hours. A 12 hour stop would be arriving at 7pm and leaving at 7am. That's more of an in-transit long driving day kind of stop. We typically arrive around 4pm and don't depart until 8am.

You can also charge at a higher current than 32A on a 14-50 in some cases, up to 40A. But at RV parks, I've heard about issues with the breakers handling sustained draw, so we do crank it down. Also, while the pedestals have separate breakers for the 30A and 50A connections, I understand that on the back end, they may be intended to supply a maximum of 40A to the entire pedestal. Since we have our camper plugged in as well as the car, I find it safest to lower the draw as you indicate.

Regarding storage in the 22 Sport, everyone likes to pack differently. We no longer hang clothing in the closet. Instead, we stack plastic sterilite bins with clothing for each member of the family, and one for dirty laundry. Under the bed goes things that aren't accessed as readily - your telescope might qualify for that. There is the storage under the benches (shoes, first aid kits, etc), and we keep one bin of pantry items in the shower.

Wouldn't the telescope be best stored in the Model X?

Ohmman, I was trying to look through the posts to see what trailer you tow behind the model x. I am thinking about getting a small trailer and was trying to get a good versatile trailer but also try to keep the best range too. Are the Rpods good for that? Thanks for your thoughts.

 

[ecarfan]

@ohmman tows an Airstream Sport 22.

Search the Model X forum for “towing” and you will find a lot of discussion. Someone recently posted somewhere asking if anyone was towing an Rpod with an X. I don’t believe anyone responded saying they were.

 

[ecarfan]

Here is some recent energy usage data while towing my Safari Condo Alto F1743, recorded while on a trip from California to New Mexico.

San Mateo, California to Casa de Fruta Supercharger 467 Wh/mi, 55mph, 75F, level road

Casa de Fruta to Harris Ranch Supercharger 504Wh/mi, 55mph, 83F, up over Pacheco Pass and down

SPEED TEST, same level highway and temp, different speeds:

Harris Ranch to Lost Hills 582Wh/mi, 55mph, 54F

Lost Hills to Bakersfield Supercharger: 649Wh/mi, 60mph, 55F

Bakersfield Supercharger to Santa Clarita Supercharger 546Wh/mi, 55mph, 65F, large elevation change (Tehachapi Grade)

Santa Clarita to Tustin 464Wh/mi

Tustin to Indio Supercharger 467Wh/mi, 55mph, 66F to 91F, no tailwind going through San Jacinto Pass

Indio Supercharger to Quartzite Supercharger 524Wh/mi, 55mph, 95F

Quartzite Supercharger to Wickenburg 605Wh/mi, 55mph, 100F

Wickenburg to Cordes Lake Supercharger 605 Wh/mi, 45-55mph, 89F (moderate net elevation gain)d

Cordes Lake Supercharger to Flagstaff Supercharger 657 Wh/mi, 35-55mph, 85F (two steep grades, large net elevation gain)

Flagstaff Supercharger to Meteor Crater RV Park 386Wh/mi, 60mph, 82F (42 miles downhill)

I have more data, but I think you get the idea. More about my trailer at A “Safari Condo” is not an apartment in the Serengeti…

 

[ohmman]

Here is some recent energy usage data while towing my Safari Condo Alto F1743, recorded while on a trip from California to New Mexico.

San Mateo, California to Casa de Fruta Supercharger 467 Wh/mi, 55mph, 75F, level road

Casa de Fruta to Harris Ranch Supercharger 504Wh/mi, 55mph, 83F, up over Pacheco Pass and down

SPEED TEST, same level highway and temp, different speeds:

Harris Ranch to Lost Hills 582Wh/mi, 55mph, 54F

Lost Hills to Bakersfield Supercharger: 649Wh/mi, 60mph, 55F

Bakersfield Supercharger to Santa Clarita Supercharger 546Wh/mi, 55mph, 65F, large elevation change (Tehachapi Grade)

Santa Clarita to Tustin 464Wh/mi

Tustin to Indio Supercharger 467Wh/mi, 55mph, 66F to 91F, no tailwind going through San Jacinto Pass

Indio Supercharger to Quartzite Supercharger 524Wh/mi, 55mph, 95F

Quartzite Supercharger to Wickenburg 605Wh/mi, 55mph, 100F

Wickenburg to Cordes Lake Supercharger 605 Wh/mi, 45-55mph, 89F (moderate net elevation gain)d

Cordes Lake Supercharger to Flagstaff Supercharger 657 Wh/mi, 35-55mph, 85F (two steep grades, large net elevation gain)

Flagstaff Supercharger to Meteor Crater RV Park 386Wh/mi, 60mph, 82F (42 miles downhill)

I have more data, but I think you get the idea. More about my trailer at A “Safari Condo” is not an apartment in the Serengeti…

Impressive numbers! With that 100D, you can almost reach anywhere.

 

[KirkNason]

Good point. I searched the site at www.teslaxcanada.ca but could not find a reference to their wheel size. Looking at the photos of their X they do not look like 22" wheels to me.

Those are 20" wheels.

 

[ecarfan]

Impressive numbers! With that 100D, you can almost reach anywhere.

Thanks, but sadly there are still intervals between Superchargers on major US highways that I’m not willing to attempt when towing my trailer. For example, Needles to Barstow CA is marginal. Based on my Model X profile in the EVTO app, it will take 90kWh at 55mph with my trailer. My concern is unanticipated headwinds. There is no place to stop and charge, even very slowly, along that 147 mile route.

 

[JimVandegriff]

Thanks, but sadly there are still intervals between Superchargers on major US highways that I’m not willing to attempt when towing my trailer. For example, Needles to Barstow CA is marginal. Based on my Model X profile in the EVTO app, it will take 90kWh at 55mph with my trailer. My concern is unanticipated headwinds. There is no place to stop and charge, even very slowly, along that 147 mile route.

You are sure right, ecarfan! Wow, remote from electricity without even any campgrounds to charge at. That stretch of I-40 could use another supercharger. Any alternate routes possible? Jim

 

[ecarfan]

You are sure right, ecarfan! Wow, remote from electricity without even any campgrounds to charge at. That stretch of I-40 could use another supercharger. Any alternate routes possible? Jim

I will be in Kingman AZ in a few days. The most direct way to continue west would be to go south to Needles, staying on I40. But instead I will go north to charge at Hendersen NV, then to Primm NV, and then to Barstow.

I have personal experience with unexpected headwinds adversely effecting range. It can be dramatic, and towing only accentuates it. And the Mojave Desert area can be very windy. I use the EV Trip Optimizer app to plan my trips, and it is very good. It takes weather into account, but weather forecasts are not perfect.

There is almost nothing on I40 between Needles and Barstow, but a possible Supercharger location would be Ludlow, which is essentially just a truck stop. But there is electricity. Just 4 Supercharger stalls there would be very useful. It’s not on Tesla’s “Find Us” page map, however.

 

[ecarfan]

I installed the Prodigy RF wireless controller too, well more like I said set me up and that is what the dealer install. I also "see 800+/wh mi at 60mph", at least during the cold weather. I have not yet tried it in warm weather. I am towing between 3,100 and 3,800 lbs.

This post was made in the thread about installing a brake controller, but I wanted to quote it here as it contains relevant and useful information. @TaylorJD appears to be towing a Little Guy Max (see Explore the Little Guy Max ) which has a total length of 21 ft and a dry weight of 3,140 lbs.

That trailer is similar in shape to my Alto F1743 (but almost twice as heavy) so I was surprised to read that at 60mph it requires over 800Wh/mi compared to the 600 - 650Wh/mi I get at that speed.

 

[bob_p]

Are there any trailer manufacturers doing aerodynamics testing or taking any measurements when they are designing their trailers? As more EVs enter the market, seems like someone will eventually figure out aerodynamics are an important factor.

A major factor in the higher energy consumption could be the difference in height. The F1754 has an exterior height of 8', while the Little Guy Max is 9' 1". Even though the Little Guy Max has a longer taper in the back, the extra foot of height could have a bigger negative impact on air flow.

 

[ecarfan]

Are there any trailer manufacturers doing aerodynamics testing or taking any measurements when they are designing their trailers? As more EVs enter the market, seems like someone will eventually figure out aerodynamics are an important factor.

I’m not aware of any trailer manufacturers doing actual wind tunnel testing, but it certainly could be happening. It would be great if trailer manufacturers started taking aerodynamics seriously, but it will be many years before EV owners represent more than a very small fraction of the total market of trailer buyers.

A major factor in the higher energy consumption could be the difference in height. The F1754 has an exterior height of 8', while the Little Guy Max is 9' 1". Even though the Little Guy Max has a longer taper in the back, the extra foot of height could have a bigger negative impact on air flow.

Good point.

The Little Guy Max has a frontal area of 109” x 84” = 9,156 sq in

The Alto F1743 has a frontal area of 95.5” x 86” = 8,213 sq in

The Little Guy Max has an 11.55% greater frontal area. But at 60mph it uses over 800Wh/mi whereas I use less than 650Wh/mi* at the same speed. So the greater frontal area is only part of the explanation. I believe the shape of the two trailers explains much of the difference. The large weight difference also makes a small contribution.

*In fact, just this morning while traveling from Gallup to Holbrook NM at 60mph I got 529Wh/mi. But that route had a net elevation loss of about 1,400 ft.

 

[bob_p]

To estimate the impact on energy consumption, you probably also need to take into account the profile of the Model X - since it's already displacing air.

The X has rounded surfaces, optimized to reduce drag.

Airstreams and Bowlus Road Chiefs also have rounded surfaces, plus the Road Chief has a tapered end, which should also help.

The Alto and Little Guy Max has square edges, which will increase drag a little.

The biggest impact on drag is likely the portion of the front of the trailer that extends beyond the profile of the Model X. Assuming both trailers are roughly the width of the Model X, the extra foot of height on the Little Guy Max is likely the because reason why energy consumption is much higher.

Again - would be very interesting to get some actual measurements... Though with the right modelling software, it should be possible to make a reasonably good estimate by building a software model of the Model X and trailer and then simulating air flow.

 

[NoBeard]

The biggest impact on drag is likely the portion of the front of the trailer that extends beyond the profile of the Model X. Assuming both trailers are roughly the width of the Model X, the extra foot of height on the Little Guy Max is likely the because reason why energy consumption is much higher.

Happy to see someone make this point, I was thinking the same but as my X is still about a week away so haven't towed with it thought it was not right to jump in just yet.
When I do have the X, I'm planning on towing one of these...

U-Haul Equipment specifications: 4' x 8' Cargo Trailer

They are shorter than the X and it will be interesting to see what the penalty is with this, since it will be well within the profile of the X and will be drafting it.

 

[aesculus]

Though with the right modelling software, it should be possible to make a reasonably good estimate by building a software model of the Model X and trailer and then simulating air flow.

Just a reminder for those using EVTO that it does have a High Profile Model X setting just for this purpose. If your trailer sticks up more than 2 feet above the Model X you should consider using it.

 

[ecarfan]

Just a reminder for those using EVTO that it does have a High Profile Model X setting just for this purpose. If your trailer sticks up more than 2 feet above the Model X you should consider using it.

Good reminder for everyone. Yes, I use that setting when planning my trips when towing. EVTO is invaluable!

I have been experimenting with the Power Factor setting in EVTO. I started out setting it at 30 but for the past few days have reduced it to 25 and am finding that is probably right for my trailer.

The Tesla in-car nav is not suitable for planning trips when towing. It assumes you will travel at the speed limit and it doesn’t seem to recognize when you are in Tow Mode and factor in the additional drag.

It would be great if Tesla could introduce a “Towing Calibration” feature: with your trailer connected, tow it for 10 miles on a level, dry, road at a fixed speed with no headwind. The car would then store that Wh/mi figure as your “Towing Energy Usage” factor. Then when selecting a navigation destination have an option to select “Towing”. The nav would then calculate energy usage differently based on that stored value. If upon the completion of the nav route the predicted did not match the actual energy usage, you could manually adjust the Towing Energy Usage factor value up or down, fine tuning it.

Tesla should hire @aesculus to work on that project. He could implement all kinds of fantastic improvements in the car nav! And also improve the Tesla app.

 

[ecarfan]

Here is some more Wh/mi data when towing my trailer from New Mexico to California this week. No noticeable headwinds, no rain. I’ve included net elevation changes for these segments as they have a strong impact on energy usage.

Taos to Albuquerque New Mexico 461Wh/mi, 45-55mph, 60-70F (1,700 net elevation loss)

Albuquerque Supercharger to Grants NM, 601Wh/mi, 55mph, 76F (1,100 net elevation gain)

Grants to Gallup NM, 500Wh/mi, 50-55mph, 69F (no net elevation change)

Gallup to Holbrook NM, 529Wh/mi, 60mph, 52F (1,500 net elevation loss)

Holbrook NM to Flagstaff AZ, 646Wh/mi, 60mph, 66F (1,800 net elevation gain)

Flagstaff to Kingman AZ, 473Wh/mi, 45-55mph, 66F (3,600 net elevation loss)

Kingman AZ to Henderson NV, 524Wh/mi, 55-60mph (1,400 net elevation loss)

Henderson NV to Baker CA 471Wh/mi, 55-60mph, 75F (900 net elevation loss, surprised energy usage was that low)