I've raced 21.5T F1 on a large 1/5th asphalt race track. Wing "Aerodynamics" never made a difference. As robk stated, the only difference I felt was the weight of the wing and how far or high it stuck out it was in relation to the main chassis or pod.
From my experience racing with a 21.5t Xray X1 on a cold dusty concrete track, probably considered very low traction, wings make a huge difference. The front wing I used was the serpent SF2 wing, and removing the flap (the top wing closest to the wheels) from the front wing made huge handling differences. Turning one corner without the flap is very stable, whilst the same corner and turning with the flap installed will cause you to spin out. I've bumped the wing a few times and it would misalign the flap, causing the car to be unstable on long straights.
Also don't buy this serpent front wing, It's a shitty wing as it bends and doesn't bounce back into shape and ends up scraping the track, plus the flap misaligns from small bumps.