Well, you can dismiss this "myth" all you want, but I can attest to seat-of-the-pants differences in acceleration and ride when reducing wheel weight by 8 lbs, each. It is real and noticeable.
As Chibana noted:
I agree about the ride; also, steering feel improvement is a good point.
The quoted post is all about wheel control, which indeed is better with lower unsprung weight and lower wheel rotational inertia. The described change in acceleration is entirely about traction - accelerating the mass of the wheels isn't a significant factor. Once the launch phase is over, the wheel mass won't make a meaningful difference. Since I don't drag race, the launch matters very little to me... and that's probably true for most people who chose a Mazda3 rather than a Mustang. I also find it interesting that his tires spin more easily now, and this is seen as an advantage...
Here's the relevant part of the quote again, but linked for context:
...Part of the better steering response was undoubtedly going from winter to all-season tires, but there was no doubt the car felt better than it did when I bought it. Steering response and precision are excellent. The tires now spin so easily at launch that today I didn't even go past the kick-down switch (in sport mode) and the front tires were spinning wildly. I'm impressed with Mazda for allowing this much tire spin with traction control enabled. It results in quicker acceleration to allow some wheel spin in a car like this.
Although Chibana's profile says 2009 RX8, these wheels and tires are on his 2014 Mazda3 Sport GT.
Once the launch phase is over, the acceleration effect is just a matter of kinetic energy storage in the rotating wheels and tires. This will not be significant, and after some searching I can only find confirmations that no one has quantitative evidence to the contrary. Many discussion references indicate that Grassroots Motorsports ran this test twice - with a Mustang reported in 2002 or 2003 and with a Miata reported in June 2011 - each time finding only a fraction of a second of quarter-mile acceleration time difference, or about the couple percent or less that a rational analysis would predict. The articles are not online, and I have not pulled the paper copies yet. I also found one amateur but relatively well-done test which shows no statistically significant difference:
http://www.nsxprime.com/forum/showt...t-wheels-Acceleration-Tests-and-their-results
Reducing wheel weight
will improve ride and handling, improving feel and even (to a lesser extent) performance.

It will also make the car
feel faster, just like louder exhaust.
