Just going by what I can get at my local Autozone. It's for a 2000 Z28. They are all made by Champion Labs. I change my oil/filter every 5K. Used to go with 0W30 Castrol now go with 5W30 since they ran out of the European one.
STP $3.29
Fram $3.79
AC Delco $4
Bosch Premium $6
Mobil 1 $10
K&N...