With the understanding that I do not drive often in California,,,, I see no need to violate the speed limit by more than 5mph most days.
If the speed limit is 55 and folks want to drive 75, Well, that is their problem. I recall a 9-1-1 call I got one day complaining about one of my State Police Troopers (Who's name by the way was also John) seems he was driving exactly the speed limit and nobody wished to pass him cause they feared a ticket. The idiot caller was complaining that he was going to cause an accident by not allowing him to violate the law... I still wish I'd ask for his name and driver's license number so we could submit the tape of the call to the prosecuting attorney in the county but I did not, I transfered him to my sgt, identified the trooper and when the sgt came back to find out who it was ask if he wanted me to relay a message.. .Suggesting "Good Job" as the message (Sgt agreed)
I have also read the instant gas millage on this ride and it stays fairly good till around 55, then it starts to drop, and around 65 it falls like a rock in free fall. 55 is good