Right in line with my sig, I guess. How far do you have to drive to "save an hour" by going 85 mph instead of 75 mph? I get 637.5 miles (8.5 hours at 75, 7.5 at 85). That's about the distance from Helena (Montana's capital) to Bismarck, ND, purely on interstate highways. Bozeman is less than a hundred miles from Helena; that's over three round-trips a day to save an hour.
Perhaps two quotes got conflated, though; a round-trip out to the northeast of the state, where there might be Bakken shale work sites, could save an hour. Of course, that means you drove all day just to get back to Helena. No wonder we need that frackin' shale oil so badly.