Use the exact weight that is listed on the oil fill cap which is more than likely SAE 5w20. You can use conventional or synthetic, which is your choice. Also use a quality oil filter such as Purolator, Bosch, Wix, or Honda filter.
Take it to a Honda Civic garage / mechanic.
What kinda does it take
4.6 Quarts of oil!
0W-20
regular
Honda civic 2003 -what is the best engine oil for hot weather?
3.5 quarts with a oil/filter change.
3.8 quarts
The 1995 Honda civic dx transmission does not come with oil filter.
A 2003 Honda civic si needs five quarts of oil.
capacity with a new oil filter is 3.8 qts. 1996 Honda civic ex
The oil sending unit on a 96 Honda Civic is right above the oil filter. The oil filter is on the back side of the engine.