New (to me) car likely in my future, as out 25 year old Audi tells us it is done. Will go fora new roof rack system for the new car. If we get the car we are thinking, it will have those recessed rails which both Yakima and Thule make decent rack systems for. Likely use a stacker type mount for kayaks on the cross bars.
Is there a big difference between aero and non-aero cross bars? Are aero bars less loud and/or is there any noticeable benefit to fuel economy?
At least for Thule, looks like aero bars are more expensive, but if I get square bars, I’d need to get adapters for most things you put on the bars. Haven’t looked as deep at Yakima, but I suspect I would find similar.
I can’t imagine aero bars are worth paying more for. Car makers have gone to great lengths to reduce air resistance, with many of the methods being quite major and yet individually, each modification has minuscule benefit, so I doubt that slight changes in shape of something that already has such a small frontal area as a cross bar could matter enough for you to detect the difference.
If your bars make noise, you can wrap them with a spiral of rope to break up air flow. I’ve seen aero bars wrapped with rope this way so it’s obvious that in those cases, the bars must have been making noise in their bare condition. I had a Subaru ages ago that had a dealer-installed rack with aero bars and it would make a LOT of noise, but only within a very narrow range of (cool) temperatures when just the right amount of rain was falling. I have extensive miles in several different cars using round bars or bulkier bars of more crude design and have never had a problem with noise. My point here is that I don’t think you can predict which bars will make noise on which cars or in which conditions, since the conditions that set a bar into resonance can be very particular.
I don’t have a 100% reliable answer, but I have one car with Thule rectangular bars and another with Thule aero bars. Both have Thule tower systems that clamp onto the door frames (no roof rails). In my case, the car with rectangular bars shows about a 10% drop in gas mileage versus no rack while the car with the aero bars does not. But the shape of the car’s roofs and other factors could be at play here too.
When I first got Thule aero bars for my 4Runner (with raised roof rails) 10-ish years ago, they tended to make a whistling noise that varied with driving speed and wind (speed and direction). The noise seemed to originate near the pillars. There’s a slot on the underside of the bars that allows the distance between pillars be changed. I covered the slot near each pillar with a 1" x 8" strip of Gorilla tape and the whistle disappeared. YMMV
I sold Thule and Yakima roof racks for may years. I’ve had both Yakima and Thule systems on my vehicles. With Thule I’ve had both “square” and aero bars. What I have found is that gas mileage doesn’t seem to be affected. Bar noise doesn’t seem to matter much. Whatever accessory you mount on the bar of your choice will almost certainly make more noise than what you are hoping for. I tried “aero” accessories expecting results and just got different noise. I got rid of them all.
My advice is to choose the accesory that best suits your purpose and buy the rack system that it fits best on. Know that once you put your boat on the rack it will make a different noise. Figure out how to fix that, keep your sunroof closed and get over it. I have gone from a Thule Aero bar system with aero accessories to their “square” bar with a Hullavator. With the sunroof open I hear no difference in the aero bar and the square bar. Throw any kayak accessory up there and you hear noise. My Hullavator sounds the same at my Hullaports folded down.
Not a good comparison, but the Honda brand aero bars on my CRV don’t make as much wind noise as my yakima round bars did on my Outback or X-terra, the bars on both of those were wider and extended beyond the mounting towers.