Get FREE email communications from Fodor's Travel, covering must-see travel destinations, expert
trip planning advice, and travel inspiration to fuel your passion.
I've done that drive a couple of times. It takes between 2 and 2 1/2 hours. That's even allowing for a stop or two to gawk at the scenery. And you really can't drive like a mad person or you'll end up in the ocean.
It will take you exactly as long as it takes the car in front of you, because there are very few places to pass. If there's not much traffic, 2 hours sounds reasonable. If you are behind a motorhome, it takes forever!
Have you been to Hearst Castle before? Do you know which tour you will take? I did the trip last year, it was awesome. Don't remember how much time it took though. See if you can get tix in advance.