I think it comes down to maybe two things - when they first built the non PID Aurelia, 2F is what they got and what they felt was good enough.

• 我想他们大致引出了两方面的事情-当他们第一次生产没有PID的奥瑞利亚，2F是他们能够做到的也是他们感觉最后的浮动。