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Road Trip Experience + Roof Cargo Box Efficiency

My family and I just finished quite the road trip in our 2021 MY LR and wanted to share the experience and provide some more data on the efficiency impacts of a large roof cargo box. I welcome any questions.

Tl;dr:Absolutely bulletproof over 2500 miles on a trip from Pittsburgh to Cape Cod to Acadia, to Burlington, and back. Loaded Thule Motion XT XL on factory rails impacted efficiency by ~14% vs rails only. You can drive anywhere with a Tesla, don’t worry. ABRP is worth it. FSD only for long trips. I dare you to find a better car for a road trip.


Background:
I purchased my MY7 “Storm” in March ’21 at the lowest price it’s ever been at ($52,990 w/ hitch). Given the savings I did load up with accessories including the roof rail and a Thule Motion XT XL cargo box (plus mats and other fun stuff like a S3XY hat for the wife). I did not get FSD but I did subscribe to it for this trip only (coupled with an early trip, I put on 3500 miles during my 30 days of FSD). Despite a few issues at delivery, I haven’t had any notable issues.

The Trip:
I planned a trip with my family to visit Cape Cod, Acadia NP, and Burlington VT over a 10 day period. We live in Pittsburgh so we made 1 stop on the way to Cape Cod but none between Burlington and Pittsburgh. I won’t go into detail on any of those specific destinations, but highly recommended for family trips.

There is one specific destination that will surely gather some attention: ascending and descending Mt Washington. This is a really fun experience in an EV and my kids learned a lot about physics! For those of you not aware, it is an ~6K high mountain in New Hampshire with a 7 mile road that goes up it. I went from 70-53% SoC on the way up, and then gained 53-61% SoC on the way down. I only had to use the brakes briefly when someone slammed theirs in front of me, beyond that it was 100% regen. I did get a few questions from people on the way up and down, and happily answered them.

IMG_2456.jpeg


Driving Stats and Experience:
  • 2500 miles.
  • 2 days and 3 hours of total driving time over the 10 day trip.
  • Efficiency was 73.62% with 711.1 kWh total use
  • 284 Wh/Mile
Overall this car is a dream to drive. It is comfortable, all of the features make it awesome. Even simple things like cabin pre-heating help out a lot when you are trying to cool off after a hike. My kids did not use the third row at all, but they are 8 and 10 and could fit it in if needed. The Y has a lot of storage space, even without a cargo box. The frunk, sub trunk, and the side storage all make for a lot of options.

AP+ FSD: Autopilot is the best overall feature, significantly reducing driving fatigue and IMO making it a much safer experience. I did not get FSD with the initial purchase but subscribed for 1 month only for this and another trip of 900 miles. In terms of features, Summon is neat but a bit scary, auto lane change and navigate are awesome, traffic light simply OK. Not worth it for my typical 15 miles a day or less of suburban/city driving. However it is great for a road trip and will certainly subscribe again before my next one!

Cargo Box considerations:
The Thule Motion XT XL fits perfectly and is probably the largest cargo box you can put on a Y. I was really concerned about efficiency and put in some dire numbers to ABRP for planning. I didn’t need to worry, the impact was minimal and likely barely affected any charging stops. I compared 2 drives, one with and one without the box (but with rails).

Drive-NoBox:
  • 178 miles, I-75+Ohio Turnpike, mostly flat some moderate hills.
  • Average speed 71
  • Outside temp 82
  • Fan average 4.5
  • 275 Wh/Mile
Drive-Box:
  • 142 miles, NY Thru-Way I-90 mostly flat, some moderate hills.
  • Average speed 76
  • Outside temp of 74
  • Fan average 4
  • 313 Wh/Mile
This works out to a 13.8% hit, which is pretty minimal IMO. Given all of these factors, I highly recommend this setup for anyone traveling with a family or a lot of luggage.


Charging Stats and Experience:
19 Superchargers, $187
58* Travel Charges (*highly inflated due to Sentry Mode induced overnight tipoffs). These were mostly free, but some charged parking fees. In one instance in P-Town, MA, the charging parking fee was significantly cheaper ($1.50/hr vs $3.50/hr) than general parking.

I had no issues with Superchargers, all worked flawlessly and were located by something useful. I did not face any waits and at least half the time I was the only one charging. I got up to 250 KW at the V3. It is super convenient to charge an EV compared to a gas car because while it is filling up you can go to the restroom, buy a snack, stretch, etc. By the time we were back to the car from whatever we were doing it was ready to go. To put it in perspective, starting the first day we began a 2 hour movie on Netflix to watch whenever we got bored while charging. We only got halfway through it during the entire trip.

I did not seek out properties with chargers except in Acadia NP as there is no supercharger nearby. Thankfully the Seawall Motel has 2 Tesla Chargers + 1 J772 and when I was there I only saw 2 other EV’s (a 3 and S). Other than the Seawall, almost all of my charging was at Superchargers, with occasional exceptions where I found a random Sema charger or similar.

Route Planning:
I never felt like I was range limited. A little bit of planning with ABRP (including a subscription) helps a lot for planning, specifically estimating the time and what charging stops would be needing on multiple waypoint days. Also, I reset their calibration at the onset and it quickly learned how much the box affected efficiency (it had it me ~309 Wh/Mile at 65MPH). That said, the Tesla nav is all I really used on the road (+Waze on in the background to scan for cops and other hazards, it helped a LOT). It is solid and never led us into any bad situations.

Side note: my rated range is still ~325 miles, in the top 1% of Teslafi. This makes me highly suspect I have the 82 kWh pack.



Overall, I have never had a better road trip or daily driver than the MY7. For anyone on the fence about purchasing, go for it, you will be happy. I'm sure I could have driven more efficiently, but in the end we were all extremely comfortable and made great overall time. This is the best road trip I've had in my life and 20% of the time I was behind the wheel of the ultimate road trip vehicle.

IMG_2438.jpeg
IMG_2527.jpeg
 
Thanks for the data! Did you consider a trail hitch box? I’d love to see a comparison.
Yes, I considered it but was rejected for a couple of reasons:

1. Anecdotally have read that anything on the hitch hurts efficiency a LOT more than on the roof and I've noticed this a bit with my bikes
2. Avoid having to only use the pull in stalls during supercharging.
3. Ability to bring my bikes and have the cargo box
4. Having anything on the hitch messes with the ultrasonic sensors which annoys me, did not want that for an entire trip
5. Was confident from reading the reviews here and elsewhere than the Thule XL size would fit perfectly
 
I think you're right that bikes on the back are bad for aerodynamics, and thus consumption. However, I think I saw a test of a box being put there and that was either null or reduced consumption (!). A box would not create as much drag as bikes. I don't have a link handy so take as unverified information, for you to look up if you feel like it.
As aerodynamics are concerned, it seems that some are running the roof box reversed front to back and are seeing better aero. The thinner part of the teardrop shape should be in the back, not on the attack (front) side, if I remember correctly. You should look that up before your next trip.
 
I think you're right that bikes on the back are bad for aerodynamics, and thus consumption. However, I think I saw a test of a box being put there and that was either null or reduced consumption (!). A box would not create as much drag as bikes. I don't have a link handy so take as unverified information, for you to look up if you feel like it.
As aerodynamics are concerned, it seems that some are running the roof box reversed front to back and are seeing better aero. The thinner part of the teardrop shape should be in the back, not on the attack (front) side, if I remember correctly. You should look that up before your next trip.
For roof racks Thule specifically says not to put it backwards. I trust the manufacturer more than that youtuber. My efficiency hit was so minimal I wouldn’t try to void my warranty and do something potentially unsafe.

Another consideration is that a hitch box may block your rear camera. It may also obscure your license plate which is inciting the 5-0 to pull you over.
 

Allx

Member
Aug 28, 2018
129
63
NJ
My family and I just finished quite the road trip in our 2021 MY LR and wanted to share the experience and provide some more data on the efficiency impacts of a large roof cargo box. I welcome any questions.

Tl;dr:Absolutely bulletproof over 2500 miles on a trip from Pittsburgh to Cape Cod to Acadia, to Burlington, and back. Loaded Thule Motion XT XL on factory rails impacted efficiency by ~14% vs rails only. You can drive anywhere with a Tesla, don’t worry. ABRP is worth it. FSD only for long trips. I dare you to find a better car for a road trip.


Background:
I purchased my MY7 “Storm” in March ’21 at the lowest price it’s ever been at ($52,990 w/ hitch). Given the savings I did load up with accessories including the roof rail and a Thule Motion XT XL cargo box (plus mats and other fun stuff like a S3XY hat for the wife). I did not get FSD but I did subscribe to it for this trip only (coupled with an early trip, I put on 3500 miles during my 30 days of FSD). Despite a few issues at delivery, I haven’t had any notable issues.

The Trip:
I planned a trip with my family to visit Cape Cod, Acadia NP, and Burlington VT over a 10 day period. We live in Pittsburgh so we made 1 stop on the way to Cape Cod but none between Burlington and Pittsburgh. I won’t go into detail on any of those specific destinations, but highly recommended for family trips.

There is one specific destination that will surely gather some attention: ascending and descending Mt Washington. This is a really fun experience in an EV and my kids learned a lot about physics! For those of you not aware, it is an ~6K high mountain in New Hampshire with a 7 mile road that goes up it. I went from 70-53% SoC on the way up, and then gained 53-61% SoC on the way down. I only had to use the brakes briefly when someone slammed theirs in front of me, beyond that it was 100% regen. I did get a few questions from people on the way up and down, and happily answered them.

View attachment 697928

Driving Stats and Experience:
  • 2500 miles.
  • 2 days and 3 hours of total driving time over the 10 day trip.
  • Efficiency was 73.62% with 711.1 kWh total use
  • 284 Wh/Mile
Overall this car is a dream to drive. It is comfortable, all of the features make it awesome. Even simple things like cabin pre-heating help out a lot when you are trying to cool off after a hike. My kids did not use the third row at all, but they are 8 and 10 and could fit it in if needed. The Y has a lot of storage space, even without a cargo box. The frunk, sub trunk, and the side storage all make for a lot of options.

AP+ FSD: Autopilot is the best overall feature, significantly reducing driving fatigue and IMO making it a much safer experience. I did not get FSD with the initial purchase but subscribed for 1 month only for this and another trip of 900 miles. In terms of features, Summon is neat but a bit scary, auto lane change and navigate are awesome, traffic light simply OK. Not worth it for my typical 15 miles a day or less of suburban/city driving. However it is great for a road trip and will certainly subscribe again before my next one!

Cargo Box considerations:
The Thule Motion XT XL fits perfectly and is probably the largest cargo box you can put on a Y. I was really concerned about efficiency and put in some dire numbers to ABRP for planning. I didn’t need to worry, the impact was minimal and likely barely affected any charging stops. I compared 2 drives, one with and one without the box (but with rails).

Drive-NoBox:
  • 178 miles, I-75+Ohio Turnpike, mostly flat some moderate hills.
  • Average speed 71
  • Outside temp 82
  • Fan average 4.5
  • 275 Wh/Mile
Drive-Box:
  • 142 miles, NY Thru-Way I-90 mostly flat, some moderate hills.
  • Average speed 76
  • Outside temp of 74
  • Fan average 4
  • 313 Wh/Mile
This works out to a 13.8% hit, which is pretty minimal IMO. Given all of these factors, I highly recommend this setup for anyone traveling with a family or a lot of luggage
That's really good efficiency (313 Wh/mi w/ cargo box), I've seen 360-415 Wh/mi with my 2018 model 3 P3D(18 inch wheels) + Yakima Grand Tour 16 . That's 12 - 30% hit over the 320 I normally get without the box.
 
@msc777 did you feel the Thule clamps didn't "grip" the stock Yakima rails well or securely ?

I love the way the box is engineered from the lock mechanism on but those clamps are supposed to cross over I believe as Thule rails are square tubes.

I'm debating if it's worth going to Yakima box to better match the Yakima engineered Tesla rails from a safety perspective.

Would love to hear another Thule motion owner's perspective. Thanks
 
@msc777 did you feel the Thule clamps didn't "grip" the stock Yakima rails well or securely ?

I love the way the box is engineered from the lock mechanism on but those clamps are supposed to cross over I believe as Thule rails are square tubes.

I'm debating if it's worth going to Yakima box to better match the Yakima engineered Tesla rails from a safety perspective.

Would love to hear another Thule motion owner's perspective. Thanks
I had zero concerns going as fast as 85-90 during the 2500 mile trip. On 2 stops midway i was able to tighten the clamps a little but I don’t think it was necessary as there was no give. They are able to cross over to an extent on factory rails. Even the wind noise was not excessive.
 
@msc777 did you feel the Thule clamps didn' "grip" the stock Yakima rails well?

I love the way the box is engineered from the lock mechanism on but those clamps are supposed to cross over I believe as Thule rails are square tubes.

I'm debating if it's worth going to Yakima box to better match the Yakima engineered Tesla rails from a safety perspective.

Would love to hear another Thule motion owner's perspective
I had zero concerns going as fast as 85-90 during the 2500 mile trip. On 2 stops midway i was able to tighten the clamps a little but I don’t think it was necessary as there was no give. They are able to cross over to an extent on factory rails. Even the wind noise was not excessive.
Thanks for your thoughts. I didn't think there was massive movement but just sat in the back of my mind that they didn't fit exactly perfect.
 
Thanks for the write up.

Planning on a similar trip and had a few questions:
1. You said you primary used super chargers ("Other than the Seawall, almost all of my charging was at Superchargers") but then said something along the lines: "58* Travel Charges" -- what does that mean?

2. The photo of google maps, what app is that?

Edit:
3. how did you track battery? (the purple graph)

Thanks.
 
Thanks for the write up.

Planning on a similar trip and had a few questions:
1. You said you primary used super chargers ("Other than the Seawall, almost all of my charging was at Superchargers") but then said something along the lines: "58* Travel Charges" -- what does that mean?

2. The photo of google maps, what app is that?

Edit:
3. how did you track battery? (the purple graph)

Thanks.

1. 58 was the total number of individual charges that got logged in Teslafi, but some of it was skewed due to a charger that kept going on and off. I would estimate that 75-85% of my juice for the trip came from Superchargers.
2+3 = Teslafi (DM me if you want a referral code)
 
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13.8% hit
I like data as much as the next guy, but I'm gonna come out and just say it: there's absolutely no way that at a -14% range hit is representative of the energy consumption penalty with a roof-top cargo box. I had a 11 cu-ft Thule cargo box (which has a smaller cross-sectional area as yours) that I road tripped with a handful of times with my model 3 2018 RWD and only on my best days would I get around 300 Wh/mi, especially at fast highway speeds. I can't recall the consumption exactly, but I remember my roadtrip from SF to SD (1,000 mi) and back probably averaged somewhere between 375-400 Wh/mi. We were fully loaded with 5 people and their stuff. It was in September, so wind resistance was at its most kind. I remember the efficiency was absolutely terrible because everyone in the car became miserable by the end of the trip. We stopped so often for charging, and it didn't help that some charging stops lack real amenities. If you have any significant headwinds with a rooftop cargo box, the efficiency drops sooo much.
 
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house9

Member
Supporting Member
Nov 16, 2019
444
528
California
…I can't recall the consumption exactly, but I remember my roadtrip from SF to SD (1,000 mi) and back probably averaged somewhere between 375-400 Wh/mi. We were fully loaded with 5 people and their stuff. It was in September, so wind resistance was at its most kind. … We stopped so often for charging, … If you have any significant headwinds with a rooftop cargo box, the efficiency drops sooo much.
Guessing your worst Wh/mi was heading back home going North bound.

I have bikes on roof and Wh/mi gets really bad heading up 101 from SLO towards Salinas when there is a headwind, as low as 1 mile per percentage. Bikes are sticking up way higher than a cargo box so probably worse with wind than a cargo box?

440 Wh/mi over a 30 mile stretch at 75 mph
- Unscientific roof rack efficiency test (Model 3)
 
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