WHEN parking uphill in a car with a manual transmission you should park with the transmission in

First gear OR reverse gear?

In both cases, let the tire contact with the curb ease some of the pressure, apply the parking brake and then place the transmission into Park. If you have a manual transmission, place the transmission in first gear when parking facing downhill and reverse when parking facing uphill.

first gear

Explanation: when parking a car uphill you use first but when parking a car downhill you use reverse.