Unless You Drive A Bugatti

Mex 200 up the coast to Barra de Navidad ot Melaque

Choose your hotel. Continuing onward to P.V. means night time driving.

Straight up the coast through Puerto Vallarta, to the Las Varas coast route or up to Tepic then straight on to Mazatlan.

I would dearly like anyone to try and beat that route for speed and avoiding big cities, both. Nothing comes near a half-dozen hours of it, even driving 90 mph when there isn't a patrulla federal.

Yes there are curves in the northern coastline of Michoacan. It's sorta neater than playing Guadalajara bumper tag, or fooling with city transitos (traffic cops).

"Say! I want to drive from Seattle to San Diego, the fastest way."

"Oh try my way! You'll love Denver or Provo".

Sheesh...

I don't want to get into a pissing match here, but these are my figures: (and I'm an obsessive compulsive when it comes to records)

April/14: Zihua to Mazatlán in one shot, via Uruapan/Hwy 37/Cuota 15D,Guadalajara, Tepic, etc. 1030 km, 13.5 hours, tolls 1259 pesos.

April/15: Zihua to Mazatlán in two days, via coast highway 200:
Day 1-Zihua to Melaque, 499 km, 9 hours, tolls 161 pesos
Day 2-Melaque to Mazatlán, 668 km, 10.5 hours, tolls 497 pesos.

Not only is it shorter via Uruapan/Guadalajara/Tepic, but quicker as well. The only drawback (aside from less chance of being hijacked or kidnapped) are those horrendous tolls of 1259 pesos, vs. the cheaper 658 pesos via the coast road.

As for the scenery.....the coast is a prettier drive, for sure. But it's only really "coastal" for the 200 km stretch along the Michoacán coast.