DOT 4 has a higher dry and wet boiling point. Important on more modern brakes that are undersized, from a thermal mass perspective, compared to older brakes. The BMW I have requires DOT 4 and a flush every two years. Time to do that, so to keep is semi related to the forum, I will be using the same Motive Power Bleeder I used on the Cambridge, just gotta get the right adapter.
Eerily enough, I was just talking about this very thing with my son just before Christmas. We were at the parts store looking over brake fluid in prep for the work on the BMW. That devolved into the various fluids in general and we were squatting down looking at power steering fluid. When I tried to stand up my right knee gave me the finger and I had to use my son as a crutch to get to my feet. He asked me if I wanted to sit down till my knee got better and I told him I'd walk it off. He responded "It's your knee, how's that going to help?" to which I told him it wasn't going to get better sitting around and I didn't have any dirt to rub on it. He got the GenX reply, lol. Anyway, I survived.