I'm going to find out how fast Starfire flies in this clip
https://media.giphy.com/media/KWB7uLgPAQEyM4vi6d/giphy.gif
Here are the pixel measurements and frame pics
Thanks to the angsizing calculator, I knew she flew 82981.95912 km. It took her 1.57 seconds to fly this far.
1/1.57 = 0.63694267515
0.63694267515 x 82981.95912 = 52854.7510318
That's 52854.7510318 km/s or 52854751.0318 m/s
That's 17% the speed of light or Relativistic
More Starfire Light Speed Feats/Statements[]
Here is a montage of three more light speed statements/feats
The first is Starfire's very first line in the series in which she tells Robin the secret to traveling FTL.
The second is Blackfire (Starfire's older sister to whom she ought to be comparable) telling the Titans about how she escaped a black hole while on her way to Earth from their home planet. It's possible she made this up considering how arrogant she is, but Star then confirms that the route she claims to have taken is full of black holes
The third and final thing is Starfire flying from a spaceship to Earth in a few seconds.