55-60 or so works great for us as well. On multilane highwhys, I just stay in the right lane. On two lane roads, I use the slow vehicle turnouts or other turnouts if I have someone behind me that was obviously going faster than us.
What I hate the most is folks who WON'T use the slow vehicle turnouts even with a huge line of traffic behind them. Or the ones who are doing 50 till you hit a passing lane, then get up to 70 or more then back to 50 when it ends.
Or SLOWLY go by someone in a passing lane so no other traffic can get around the slow vehicles.