Multiplying part velocity by 0.8 somehow increases it?

I’m currently making a plane, and it kept spinning in light speed. I tried to slow it down by multiplying 0.8 to the Velocity property of it, but it somehow makes it worse and it spins even faster now.

The issue isn’t the velocity but the Rot-Velocity. Slowing down the movement would increase the rotation speed as the point it is spinning hasn’t got so many external factors and has a more stable centre point.