Re: Back in the distant past, before I worked for HP...
My first car could just about do 60 when the federal limit was 55. SF to Santa Barbara on 101 was 6 hours. Then on to LAX was another 90 min. So Sac to LAX by the scenic route was around 9 hours. Doing the straight I - 5 would knock almost two hours off that.
I never did do The Grapevine in that car but I did do the Conejo Grade on 101 and the 17 Summit many times. Even when the temperature was 100 plus. Thats when I learned to drive with the car heater going full blast. To keep the engine from overheating while climbing the grade. That heater trick has saved me on a number of occasions. Although it is a new form of misery to run the heater full blast when the outside temp is well into the triple digits. Builds character.
I once did it for several weeks while driving around Los Gatos during the summer (into the triple digits most days) before my mechanic told me when I left my car in for a service that the reason why the engine was running hot was because there was almost no coolant flowing through the radiator. Turns out that old BMW's had very very good heaters.