2500mi Yakima Roof Box (and Toddler) Roadtrip Insights

[ebeponyan]

I want to preface by saying that the primary goal on this trip was to survive. Any data and subsequent analysis that comes out of this is going to be fraught with caveats and uncontrolled variables, but hopefully provides some context for the curious. Speaking of context, we're based in the North Puget Sound region and got an invite to a friend's wedding in the Bay Area. As we didn't want to undergo the hassle of air travel with a toddler and wedding clothes, the only sensible option was a two-week, 2500 mile electric slide down the Pacific coast in our Mach-E. As you may have surmised, I am alive to tell the tale.

Just a couple of ponies with roof racks. Taken nervously out of our cabin window at Prairie Creek Redwoods State Park in CA.

A lot has changed both for us and the Mach-E since my last major trip report in 2021. There's a baby, a roof box, an OBDLink/CarScanner, BlueCruise, different tires, and more. The format of this thread though, much has like my lack of frunk button, will remain largely unchanged. Over the following hours/days I'll be adding posts to cover a number of topics, including data from fast charging and roof box driving efficiency. In light of that, I may dodge some questions until I'm able to push those sections out, but ask away.

Before and after.

On the final leg of the return journey we crossed the 30k mile mark and our HVB SoH dipped to 97%. I'm skeptical of that 2.8mi/kWh reported on the Trips app. I've noticed a bug where Trip 1's efficiency is linked to Trip 2's and does not properly reset. I'd wager on something more like 2.6mi/kWh generally going 60-65mph on a healthy mix of coastal highways, plateau/lowlands freeways and mountain passes. More on that later. The temperature ranged from low-40s to mid-80s, but was primarily between 65 and 75F.

 

[67 Stang Convertible]

Please tell me that photo of "Prancer" watching Sentinel over your Mach E is fake or real? 2500miles, did you fast charge the whole way or mix of DC fast and overnight plug ins?

ps. congrats on the baby.

 

[ebeponyan]

The Roof Box

Plugging in *like a glove* while exploring Oregon's Prehistoric Gardens. Clearance isn't generally an issue since the Mach-E has such a low profile, but it's always something to keep in mind.

Why this roof rack?
Thule was the only manufacturer with a fit kit on the market at the time. I don't know if that's still the case, but these bars served us well. We took the leap from this post highlighting a good price, and while the bars arrived a little scuffed up (probably from international shipping), the installation went smoothly. On their own, they produce low, but noticeable wind noise, particularly at moderate speeds when you occasionally catch a whistle in the wind to accompany the front motor whine.

Why this box?
We needed a cargo box that can carry two bouldering crash pads. These are lightweight, but bulky and surprisingly rigid foam blocks that tend to fold to around 36"x24"x10". While many cargo boxes appear to support this by exterior dimension, the tapered ends on most boxes end up too low to fit two pads at a time. Of note, the cranks for the clamp mechanisms on all Thule boxes are permanently elevated a few inches off the base, which is fine for skis, but does not accommodate boxy items. For our niche purposes, Yakima's CBX-16 was the lowest profile and cost option that satisfied our requirements. Definitely catch a sale if you can wait.

Fit testing some other models at REI

Why is it sitting so far forward?
The shape of the roof dictates the placement of the roof rack's bars (Thule specifies in their installation manual), this cargo box is pushed as far back as its tracks will allow. A larger 18L model would extend further back without quite interfering with the tailgate for a possibly more symmetrical look, but that was more box than we needed (from a dollar and an aero perspective) and it's possible that would interfere with the signal to the sharkfin. No data there, unfortunately, but we didn't notice any issues with the 16L box.

What is the range impact?
This is probably everyone's main question and was certainly my own going into both this trip and the purchase of a roof box in general. I wish I had a clearer answer. Something like 15-20%, but it depends. I'll include real world numbers I have at a variety of speeds, but there are so many uncontrolled variables at play between wind speed/direction, elevation, temperature and road conditions that I don't feel even the sample of over 1000 miles of decently continuous and complete data I selected is enough to give a definitive answer (especially without a control to compare with). Aerodynamics factor in increasingly at higher speeds. For reasons both practical and legal, my testing did not go beyond 70mph, but you might as well be driving a Lightning as far as highway efficiency is concerned. Even on higher speed limit roads, I'm not sure I'd venture much higher than 70mph just with noise, efficiency and strain on the components in mind. See data:

mph_range	sampled_miles	kwh_consumed	mi_per_kwh
~40-50	248.2397108​	94​	2.64​
~50-60	663.8265324​	256.46​	2.59​
~60	213.0472177​	82.16​	2.59​
~60-65	415.7391758​	161.84​	2.57​
~65	196.4813659​	78.55​	2.5​
~65-70	181.8682544​	76.44​	2.38​

I'm not planning to go into detail on methodology, but while this data is neither clean nor pure, it lines up pretty well with reality. I do want to highlight that on a more or less uninterrupted 50 mile stretch with relatively little wind and elevation difference at with mildly warm ambient temperature, we saw an improved 2.65 mi/kWh at 65mph. Based on our experience, I'd say to expect a 220 mile range from 100-0% with BlueCruise set to 65mph rising to 250mi in favorable conditions and lower speeds. I also want to call out that there is a correlation between lower speeds and significant elevation changes on winding mountain roads which is definitely skewing the lower brackets down.

Noise?
No whistling from the box, just a dull roar that gets a little less dull the faster you go. At highway speeds, the wind noise is prevalent, but not overwhelming. It's not a perfect measure, but we generally bumped music volume two ticks above our usual to compensate.

 

[mdolan92869]

Was a guard moose/elk/reindeer a security option that I missed?

 

[ebeponyan]

The Elk in the Room

I suppose this needs addressing. Evidently there are elk at Elk Prairie Creek. They just kind of go where they please while you stand in awe within your cabin walls and try not to make eye contact.

That's the spot

This would make for a pretty sweet decal.

a n x i e t y

 

[ebeponyan]

Please tell me that photo of "Prancer" watching Sentinel over your Mach E is fake or real? 2500miles, did you fast charge the whole way or mix of DC fast and overnight plug ins?

ps. congrats on the baby.

Thanks, I have a post or two coming about charging, but we leaned heavily on overnight charging to minimize, but not eliminate, fast charging.

 

[A-A-Ron]

This would make for a pretty sweet decal.

Yes it would

 

[azerik]

Wow I learned something today. The bouldering crash pads are not desert yoga mats like I thought!. We have a LOT of people lugging those out to South Mountain, I always thought they were just very dedicated Yoga peeps.

Nice trip and great color!

 

[ebeponyan]

Charging

Plugged in at Costco Gas just for the novelty

This will probably be my longest entry. Maybe I should have split it up, but oh well. Hold onto your attention spans. All told, our complete charging bill was $97.55 for just shy of 2500 miles. That includes preconditioning and filling back up at home. A decent chunk of that was also discretionary where we may have stayed somewhere less interesting with a charger, or parked less conveniently and not paid for L2 charging to keep the spot over lunch. Gas (what's gas?) is not cheap on the West coast, so even at a very generous $4/gal, ICE would need over 100mpg for price parity. Not that I have to convince anyone here. It's worth noting that we're still on the BlueOval Charging Network EarlyAccess trial, so we get member pricing at Electrify America. I guess that $4 membership fee would otherwise have put us over the $100 mark.


AC
For toddler reasons, we limited most of our days to under 4 hours of driving, which generally meant we could plug in at a destination charger and eschew fast charging entirely. There's an argument for hammering out another couple hundred miles per day after bed time, but road tripping has always been as much about the journey as the destination for me, and those are all miles you can't afford to make meaningful stops at lest the baby wakes up. The flip side of this is nap time. Be prepared to sacrifice potential stops or to inject significant layovers at any moment when nap time cometh. Even L1 charging will provide a nice boost of 50+ miles overnight which can open up a lot of potential stays that aren't particularly close to fast chargers.

A 120V hookup like this one at Cape Blanco State Park cabins or asking nicely for access to exterior outlets at hotels can net you 20kWh overnight.


Adapters

TeslaTap deployed

I would recommend investing in a 60A TeslaTap for destination charging (at least until the Mach-E is outfitted with Tesla connectors/adapters). Many hotels will offer both Tesla and J-1772 chargers, and the TeslaTap opens up more options and better insulates you from charger reliability issues by offering more redundancy.

A closer look at a 120V RV hookup

While it is possible to use a TT-30 adapter for 120V RV hookups (see photo above) on a portable EVSE that is limited to 24A (NOT the Ford Mobile Charger), that's a lot of gear to pick up for very little benefit. As far as I've seen (sample recording below) all 120V charging on the Mach-E caps at 1.2kW. That means even though the TT-30's circuit could supply double that, the car will only ask for 1.2kW. You might as well just plug the Ford Mobile Charger into the standard outlets that almost always accompany a TT-30. In cases where 50A 14-50 hookups are available, the Ford Mobile Charger works great.

Quick sample showing the power limit and kW to battery (I expect this would have ramped up toward 1.2kW if the car was off) for a 24A EVSE with TT-30 adapter.

DC
One of the perks (silver linings?) of traveling with a toddler is that you never need to stop to fast charge. You need to stop for any number of toddler-related reasons, and can just happen to charge in the meantime. Fast charging was almost exclusively at EA with the rare exception of the occasional free fast charger. Criticism of EA is justified, but it's still the best all around CCS network that we have in the States.

Night vibes at EA Chico, CA

We did, inevitably, encounter one charge fault. It's the classic Spidermen pointing meme of the car saying station fault and the station saying car fault. However, after a few minutes of turning off and back on again and unplugging and plugging back in, the session picked right back up and carried through. See data:

Boy I hope the legend is visible. Dark blue is kW into the battery. It's worth noting that the charger delivers 5-15kW more than this due to losses and powering the coolant loop. That first peak of 153kW was actually more like 164kW at the charger.

I'll include another curve below from a more normal charging session later in the trip, also at Electrify America:

This does a better job illustrating the initial spike in kW resulting in an initial spike in temperature until the peak backs off and coolant loop starts to catch up. The new 80% cliff is so much more reasonable than it used to be.

As far as reliability and availability goes, we mostly avoided long weekend drives and the main corridor of I-5, and therefore didn't really encounter bottlenecks. We did have to pass for a later station once when all stalls were taken by Bolts and an i3 in the time it took us to get off the highway, and they may still be waiting to hit 80% to this day. One EA location we used had something like 2/9 stations operational, but we were there on a Tuesday morning with no traffic. Plug&Charge was about 50% successful, so I just got in the habit of firing up FordPass as I waited to see whether the charge would initiate on its own.

 

[ebeponyan]

Problems

Every forum's favorite section, wherein we complain about small things that didn't really negatively impact our lives. We got off to an inauspicious start by losing a mud flap fastener on the first leg.

Mud flap now with 50% more flap

After hastily applying a zip tie, we popped into the next Ford service center on our path. While they didn't have the part in stock, the zip tie held strong, and it is still a small comfort that there are so many Ford service centers spread across the vast wastes of the West. Ultimately a non-issue, should be sorted out when we finally get through the Key Fob CSP at our home dealership next week.

No trip report is complete without charging issues, but ours were fairly benign this time. Detailed above.

BlueCruise 1.0 was largely reliable, but did struggle on the divided sections of 101 in California. In the right lane, hands-free would disengage on every exit, and usually not re-engage until 5 seconds before the following exit. Speed sign recognition also had a habit of occasionally picking up truck speed limits and slowing to those.


The Main Thing

What in tarnation?

EDIT: I haven't seen this for several months now, so presumably fixed OTA. Keeping it up for visibility though.


The primary bone I have to pick is with the updated intelligent range calculation feature that rolled out with OTA 4.6.2 mid trip. This feature was plagued with arbitrary reductions of large chunks of miles on startup in Early Access testing, and I'm happy to confirm that these issues were very much not resolved before rolling out to a wider audience a year later. Naturally, my first encounter with GOM shenanigans came in the Northern marches of California that possess a great deal more mountains than chargers. On the way up, the intelligent GOM did a decent job of sensibly knocking off a bit of range to account for the ascent, and our arrival SoC of 43% at an intermediate destination was pretty close to what in-vehicle navigation predicted after the adjustment. Working as designed. That 43% afforded something around 110 miles to get to our destination charger 50 miles away.

When we returned to the car and started back up, that 43% now accounted for 42 miles on the GOM. Lord have mercy on you if you're not an active forum member who's been aware of this potential bug for a year, haven't planned this route numerous times with different configuration settings in ABRP and don't have live OBD data helping you through the math when your car erroneously tells you to abandon all hope; there are no chargers in range. We ended up rolling in at 23%, which was roughly in line with ABRP's initial estimate and even not far off the inital intelligent range adjustment. Even after plugging in, the silly numbers stuck around on the GOM and in FordPass until morning, suggesting a whopping 132mi at 100% (see picture). This is not an acceptable experience, @Ford Motor Company (no complaint post is complete without invoking this account in vain), and will only serve to erode faith in Ford software and EVs in general. It's a decent feature when it works, but I cannot trust or rely on the GOM if it's liable to just occasionally put up clown numbers.

Here's another instance of GOMfoolery from more recently. This was not an isolated incident.

Related to the GOM and range estimates, I also notice that fast charging with navigation active will send a notification to FordPass with messaging that indicates you can unplug and drive off to your next destination with a zero mile buffer. That's maybe not the best idea when the GOM is so detached from reality. If I listened to FordPass in these instances, I would have been stranded on multiple occasions.

 

[ebeponyan]

Notes on Packing

Living the frunk life

To get back on the lighter side of things, and as a Dr. Mario enthusiast, I can't help but include a section on making the most of the Mach-E's ample cargo space. Just setting the roof box aside for this one, since that's its own beast and filled to the absolute gills with climbing and sleeping gear.

Toddlers require several times their body weight and volume in stuff when traveling. Just an absolutely unfathomable quantity of stuff. Furthermore, our plans to meet family down at the wedding venue to help with child care necessitated that the seats remain up and operational throughout the trip. Likewise, we needed to leave room for their bags in the trunk, which ended up meaning we had full rear visibility for most of the trip, which is nice. Everyone has their own packing needs and strategies, but I do want to call out a few tricky items that the Mach-E accommodates brilliantly. I didn't have the presence of mind to snap pictures of all of these during the trip, but here are some faithful recreations as needed:

Strollers

It is deeply satisfying stash the stroller away in the frunk, especially now that our toddler is moving around on his own. It wasn't required most of the time, but was a nice comfort that remained out of the way until we needed to make use of it. Among miscellaneous jackets and shoes, the frunk contained a cooler bag for shrimp and our mobile charger with adapters. This allowed us to more easily Tetris a handful of larger bags into the trunk without awkwardly shaped and sized items bouncing around.

Baby changing area

We managed to get our bags and Pack&Play to sit relatively flush across the trunk which gave us a platform for changing (or eating, as pictured) without needing to unpack or search around for a flat surface. In the past we've also set a changing platform up in the frunk, but the forward slant is a little inconvenient.

Suit bags, dresses and heels

These all went flat under the false floor in the back. They didn't get a second thought for a whole week on the road and came out in utterly pristine condition on arrival. We laid cardboard down for a uniform surface and were able to stack a couple of garment bags up without the false floor applying any pressure from the top.



Hope this brings you inspiration!

 

[JohnFoxeSheets]

You know I’ve road tripped with two cats in my trunk, but I never thought about putting a toddler in a roof top cargo box. I presume that if you're at speed you can’t even hear the kids crying. Good call!

PS. Sorry, I couldn’t resist.
PPS. This was decades ago when we were moving from Southern California to San Francisco. The cats were in the trunk so they could sleep in their carriers and it would be quiet for them. The back seats were folded down they had lots of fresh air…

 

[ebeponyan]

PS. Sorry, I couldn’t resist.

You'll be pleased to know that I wrote this joke in at least two times initially, but deleted it for being juuuuust too corny.

 

[JohnFoxeSheets]

You'll be pleased to know that I wrote this joke in at least two times initially, but deleted it for being juuuuust too corny.

I had to skim the whole thread first to make sure I was the first one with standards so low as to put it in writing

 

[Say Watt]

You know I’ve road tripped with two cats in my trunk, but I never thought about putting a toddler in a roof top cargo box. I presume that of your at speed you can’t even hear the kids crying. Good call!

PS. Sorry, I couldn’t resist.
PPS. This was decades ago when we were moving from Southern California to San Francisco. The cats were in the trunk so they could sleep in their carriers and it would be quiet for them. The back seats were folded down they had lots of fresh air…

Is your real name Schrödinger? I understand he used to have a cat.

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