You're right. You tested it, so you must be right.
I don't think I'm the one being an asshole here...
Gotta love people coming into a thread like this and speaking information as fact without specifying a source. It doesn't even matter if you're right, you just make yourself look like an asshole.
No traction difference what so ever, it's only visual. Just like spoilers and bumpers are only visual.
That being said if you'd like to correct yourself by stating a source, I'm waiting.
I have tested this with a few different cars with every wheel type and nothing changed. Same amount of wheel spin, same amount of tire smoke, and same grip around corners.
I even put high end wheels on my Mesa2 and went off-roading and couldn't tell I had street tires other then by looking at them.
Placebo effect anyone?
Oh wait, everyone else in this thread has tested it too...and 90% of them say you're wrong.
The mind is powerful!