Perks have you tried using the manual mode at all? I think it will do better than the cvt at constant speeds above 60mph. The CVT will tend to shift up or down needlessly due to small grade changes, while the manual mode keeps the engine more constant at a very high gear ratio. If you're not familiar with manual shifting, it is really quite simple. The gear number shows up in the gauge and little arrows tell you when to upshift. The car will also automatically downshift when you slow down, so you only have to worry about upshifting. You can also switch modes while driving.