So you need help determining the best crossbars for your car. Whether your replacing old bars or buying for the first time; you've made the right choice looking at Thule products.
Basically, you want to know if the aerodynamic WingBars are really worth the extra cost. I can't tell you which to choose, but I can tell you crossbars will be on your car for the entire car's life.
Treat crossbar selection like an investment because you will be with them for the next 3-5 years.
30 Second Summary: Square Bar vs WingBar
Bottom Line: Square Bars are for people who don't mind wind noise at speeds above 40 mph or who intend to have a bike or kayak rack mounted year round.
The WingBar are the better investment because they are silent up to 70 mph, have a top track, and are more stylish in general. Those who have racks on their car for only a season at a time will find great benefit in the reduced noise.
Additionally the top tracks allows the WingBar to be compatible with the latest bike and kayak racks.
Thule Square Bar vs WingBar: Key Differences
The Thule WingBar is a newer improved version of the classic Thule Square Bar. It is a crossbar designed with user experience in mind and not just functionality.
Related: For the most aerodynamic bar see Aeroblade vs Whispbar
Aerodynamics
The Square Bar is aptly named because it is quite simply a square shaped bar. Something you don't see are race cars with a square shape. This is because air cannot flow past square shapes easily at high speeds.
Air resistance impacts vehicles in two ways: reduced fuel efficiency and wind noise.
By changing from a square to an aerodynamic "wing" shape, Thule evolved its product and greatly reduced these two factors.
Top Channel (T-Slot)
Top tracks are a narrow channel along the top of the crossbar that is used to attach kayak or bike racks to the inside of the crossbar. T-tracks offer quicker install times, reduced theft, and a more secure attachment point.
The Square Bar requires racks to clamp around the outside of the bar. Racks that do this tend to slip and roll over time. Long road trips will require occasional tightenings leading to less peace of mind.
Price
The older Square Bar's primary appeal is it's affordability. For the quality workmanship of a Thule product, the Square Bar's price point fits into most people's budget.
The WingBar will run owners about a double the price of the Square Bar. However premium features and savings from fuel efficiency improvements make it a sensible purchase.
Either way you cannot go wrong with a Thule crossbar.
Related: Yakima Jetstream vs Aeroblade