For the most part, I was cruising between 57-60 mph the entire way. However, there was one point when I got passed by an 18 wheeler (it was a 4 lane highway so plenty of room) that was barely going faster than me. When he passed me, he got over into my lane and immediately my speed increased because I was in his draft. I let off the throttle when my speedo showed 65 mph!
Not once did the engine seem like it was struggling or winding out too high, even when I drafted that big rig.
In the future I'll get my fiance to park on the side of the highway and video tape me as I pass her doing 60+.