How fast do you go

I'm in Canada so I do the posted limit up to 110 KM/H which is about 68 MPH. Secondary highways are only 100 KM/h. I only go faster temporarily to pass if I need to. If someone's doing 108 in a 110 zone, I'll just stick with that. I try not to exceed this as after that it hurts fuel economy and the road is usually crowded so sometimes even less. I can stay just under 2000 RPM's at 110 even while towing. 100 KM/H seems to be the sweet spot though. I try to not be in a hurry. I'd rather get there all in one piece.