Whispbars, what is the largest possible cargo carrier?

[JohnnyMarshal]

I ditched my Infiniti QX56 for a 2015 Model S. Occasionally I would use my Yakima Skybox 21 in the QX. I think its the largest one they make. Can I add Whispbars and throw the Skybox on top? I'm guessing it will kill my mileage. Anyone have experience how much?

Here are the Skybox's specs:

• Weight: 62.00 lbs
• Dimensions: L 92.00" x W 36.00" x H 18.00"
• Approved Crossbar Spread: 24" - 42"

 

[ArbitrageMan]

I’m not direcrly answering your question, but michael subasic has a video on this. He indicates somewhere between 5-15% reduction in range.

...Im doing the same research myself to see which box I should buy.

 

[tfinan]

Here is a picture of a Model S with that box installed.
[URL="https://teslamotorsclub.com/tmc/posts/1960044/"]whispbar with cargo box[/URL]

 

[hevakmai]

I’ve used a Skybox 21 on a Model S several times. Expect about 400ish Wh/mi on flat road (this is typically 330Wh/mi for me without the box). It will increase the drag of the car quite a bit.

 

[JohnnyMarshal]

Thanks everyone! I'll give it a whirl.