Texas speedo methods...seat of pantsfell fr speed and IF no one passes me, I must be doing right.
Or have wife drive the truck at 60 and I follow and check on tach. Then just go by tach.
I also use tack to tell me when low on gas!!
I got a ticket for 43 in a 40 once so I need it to be a little more accurate. Unfortunately living where I live I would need a clipboard and a sheet of paper with different rpm/mph on it for all the different speeds.
