Do people get bigger wheels just for the aesthetics? Is there a performance benefit?

[Mental]

Originally Posted by cs123

I think the Mazda guys was making the point that it's not the weight, it's the radius of gyration that can affect acceleration and braking performance.

As you increase the rim size you more than likely will increase the radius of gyration and this will have an affect, although I'm not sure what the real world impact is.

You also need to start looking at maintaining the strength while keeping the mass of the rim under control.

Someones on the ball. I don't have the maths for it, but even if the rim is only a couple of kilo's heavier, the mass of the rim is now 2 or so more inches further out. Meaning that it has a greater surface speed compared to your old 14" rim. Thats where the extra energy is needed to accelerate or brake a bigger rim.