This test is pretty flawed:

> IPv4 requests went first, then IPv6, and we recorded the average latency of the 3 requests as the resulting data point (using a float value in milliseconds).

On wifi, the IPv4 requests are going to wake up your radio, and then the latency is going to be better for the IPv6.

On wired, there's very little difference, since there's no radio wakeup delay.

Pinging your default gateway isn't much of a test anyway.