Always go by the manufacturer's recommendations in the owner's manual. That being said, the manufacturer recommends different weights of oil depending on climate and use. I always use 5w30 because it fits within the temperature range here. You can also use 10w30. Always change your oil filter when you change your oil. The best filter I've found for quality and price is the Motocraft 400s Filter.
No
A 2003 Jeep Liberty uses red, hoat, five year coolant.
Yes, you can.
The fuel pressure of a 2003 Jeep Liberty Sport depends on the usage of the car. It can also depend on the elevation.
Half an half
On a 2007 Jeep Liberty Sport, it is located very low behind the bumber on the drivers side. ----
i guess the '03 is newer?
5 year, HOAT. Not Dexcool.
add r134a to the service port
5w30
1-6-5-4-3-2
Mounted on top and inside the fuel tank.