Thule rails and Force XT XL roof box installed & efficiency tested

[thekat03]

I've been testing my car's efficiency this week in preparation for an upcoming trip, and have had my roof rails and (extra large) roof box on during my daily commute (20 miles, 30 minutes, largely country roads).

Seeing about an 11-17% hit on efficiency, which isn't insignificant, but doable for using this car while hauling 2 adults, 2 kids, 2 dogs, and assorted gear for a week at the cottage. I expect worse numbers at freeway speeds, but that's true with roof box or not.

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[MikesMachE]

Just curious, what are the rails you have installed? Is it the Thule Wingbar Eco in the 150 cm? Do you know if the 135 cm version will fit? My previous vehicle used the 135 cm version, so ideally I could just use those and purchase new clamps to fit the Mach E

 

[thekat03]

They're the Thule Wingbar Evo 150cm bars. I also have the 135cm ones from my old Prius, but didn't think it was worth gambling, so we just bought the new bars. At almost 6" shorter, it is questionable if they would fit, but possible. If you have the time, you could probably order just the feet and see, but we wanted this set up as quickly as possible to do some efficiency testing before our trip.

 

[Billyk24]

Another option is to use a rear hitch mounted cargo carrier. Several name brands make them including Thule. There is a bottom rack that is needed with these cargo carriers. These will not have as "much" of a drag as roof top cargo boxes.

 

[thekat03]

Another option is to use a rear hitch mounted cargo carrier. Several name brands make them including Thule. There is a bottom rack that is needed with these cargo carriers. These will not have as "much" of a drag as roof top cargo boxes.

I am likely to eventually get a hitch on my CR1, but need to find someone I trust to do the install well. I already had this roof cargo box that we had purchased to use with a prior vehicle, and went to LL Bean for the roof bars (I live in Maine, and the flagship store is nice!). The hitch shelf we have kind of gets in the way when our dogs hop out, however, so it's not my favorite option for full family road tripping. My beagle ripped a nail off last winter when she caught her paw while hopping out the back of our old road trip car. The dedicated hitch mount cargo boxes probably would be better, but not sure it's worth the cost right now, compared to using what we already have. We want to do more efficiency runs with both my car and my husband's C40, which has a hitch and official towing capacity here in the US, and does very well pulling our small utility trailer, to see what our options are, depending on cargo space requirements.

 

[Billyk24]

Ecohitch doesn't really stick out when not in use. Simple installation.

 

[thekat03]

Ecohitch doesn't really stick out when not in use. Simple installation.

Sure, but more than I want to tackle myself, since it's outside my field of expertise, and day job sucks up so much of my time. So I will hire someone, eventually. For now, buying the rails was cheaper and faster than buying a new hitch, professionally installed, and a new hitch cargo box.

 

[dj_stang]

Why was this blasted to everyone? It’s just a regular post. Did Thule pay the admins or something?

edit:
@Administrator can you please fix this. It may temporarily drive engagement but we don’t want people to be desensitized. Engagement seems really good as is anyway.

 

[thekat03]

Why was this blasted to everyone? It’s just a regular post. Did Thule pay the admins or something?

Oh, is that why it's suddenly getting seen again? That is so weird. Computer algorithms thought people need to haul more stuff, I guess.

 

[Jim622]

Why was this blasted to everyone? It’s just a regular post. Did Thule pay the admins or something?

I was wondering the same thing.

 

[Jim622]

How much range will you lose with that big ugly sail on the roof?

 

[Teslaeata]

Don’t think the ‘Stang will carry much more than it already does inside on a normal day out which is most days and over most of my 66,000 miles………..

 

[Teslaeata]

I was wondering the same thing.

Mee too!

 

[thekat03]

How much range will you lose with that big ugly sail on the roof?

We got 2.4 miles/kWh on freeways with it, so... almost 100 miles? Yeah, it's not pretty, but doing that 2-3 times a year and driving my pretty MME CR1 the rest of the time is better than driving a big boat of a vehicle all the time.

 

[Nikos]

I've been testing my car's efficiency this week in preparation for an upcoming trip, and have had my roof rails and (extra large) roof box on during my daily commute (20 miles, 30 minutes, largely country roads).

Seeing about an 11-17% hit on efficiency, which isn't insignificant, but doable for using this car while hauling 2 adults, 2 kids, 2 dogs, and assorted gear for a week at the cottage. I expect worse numbers at freeway speeds, but that's true with roof box or not.

Now that you made the investment on this good looking roof box, that you going to have a 10-15% loss on mileage. You can keep your loss closer to 10% if you watch/limit your interstate speed at a maximum of 70mph. 65mph would be ideal. That roof box is aerodynamic enough to help with your losses.
10% is something you can live with on your travels. You will find out how to mitigate your extra aerodynamic load on your SOC and mileage range.
One owner in this forum has installed a hitch so he can carry a lockable box.
Myself have installed a TorqueLift 2" hitch to carry Fat tire E bikes. Installing a hitch is not inexpensive either.
It is just a choice of how you want to transport your gear while traveling.
Your rails can be used to carry other toys, such as skis, kayaks, bikes or rooftop tent. Whatever you do with those roof rack bars, would impact your mileage range. You will find out, adjust, experiment with and live with it. It is not as bad as you may think.
I have a Lightning also with a rooftop tent. I have a 10% loss of my mileage if I stick with a 70mph speed limit.
Plan your charging stops by giving yourself a little bit of cushion.
You're going to do fine.

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