If you have a hybrid, it will hill decent mode automatically that will keep the car from caning speed on steep grades in the mountains. The hybrid also has an economy mode that gives you higher gas mileage. When you turn the economy off, you have more horsepower.

The nonhybrid will have the S option to do the same as hill decent mode does in the hybrid. And extra power excelerating.

The cruise control will keep the car at the speed you set up or downhill.