Pretty much when I started skiing 3 years ago, I got a ski roof-box for the car (aka Pugmobile). It made sense at the time because we would normally fit four people in the car, plus the skis, baggage, etc. However, for the last couple years, it went unused because it's mostly two of us heading there, or just solo day trips, or we just take two cars because of logistics in long trips. So, I decided to remove it, since I didn't like the road noise and the unnecessary bulk.
Wow. I only took one trip since then, 3.5 hours to Tahoe. On the way there, I kind of noticed the difference in mileage but it wasn't too focused on that. On the way back, I filled the tank right before heading home, and I got home with a little less than half a tank. This is considerably more highway mileage than I used to get with the box mounted on the roof.
I searched around in the "Internets", and I found all sort of data. Data are anywhere in the 3% to 40% mileage penalty when using a roof box. I think a wide range of results is expected since because there are so many variables in play. Incidentally, car design involves a lot of thinking about minimizing drag (aerodynamics), as we all know. This article scratches the tip of the iceberg, and also discusses some of the fundamentals of air drag (See also here).
Anyway, I wonder if any of you have any hard (or soft) data from your own experience with using roof-box (or roof-rack) on mileage. Something like highway mileage, with and without the box. We could compile some numbers. Neeeerdy, yayy! Before anybody asks, sorry, but no, I don't have the data and I am not spending 2 hours mounting my box again for a test. And yes, I bought a cheaper box that takes a degree in mechanical engineering to put together.
Thanks!
Wow. I only took one trip since then, 3.5 hours to Tahoe. On the way there, I kind of noticed the difference in mileage but it wasn't too focused on that. On the way back, I filled the tank right before heading home, and I got home with a little less than half a tank. This is considerably more highway mileage than I used to get with the box mounted on the roof.
I searched around in the "Internets", and I found all sort of data. Data are anywhere in the 3% to 40% mileage penalty when using a roof box. I think a wide range of results is expected since because there are so many variables in play. Incidentally, car design involves a lot of thinking about minimizing drag (aerodynamics), as we all know. This article scratches the tip of the iceberg, and also discusses some of the fundamentals of air drag (See also here).
Anyway, I wonder if any of you have any hard (or soft) data from your own experience with using roof-box (or roof-rack) on mileage. Something like highway mileage, with and without the box. We could compile some numbers. Neeeerdy, yayy! Before anybody asks, sorry, but no, I don't have the data and I am not spending 2 hours mounting my box again for a test. And yes, I bought a cheaper box that takes a degree in mechanical engineering to put together.
Thanks!