Mexico City to Zihua Drive

I know must people know this, but I was surprised how long the drive is from Mexico City (7 and half hours according to Google). I had looked at the map many times over the years and it looked much shorter. I guess mountains and some poor roads cause this.

Here along the coastal highway, the 80 or so topes between Zihuatanejo and the turnoff to bypass Acapulco make a 3 hour drive take 4. Once on the Autopista del Sol it's a breeze. The first time I drove between Acapulco and Mexico City it was on the old federal highway, and it was about a 6-hour drive, 8 by bus because they stopped in most every town along the way.