It depends on what year you are speaking of in the 90's. The 4th gen Civics (1988-1991) had two engine size choices in the US ( I won't get into Japan or Europe): 1.5L D15B and the 1.6L D16A6. All Civic trims but the Si got the 1.5.The 5th gen Civics (1992-1995) had four engine choices for the US: 1.5L D15B7 used on the DX and LX models, the 1.5L D15B8 used on the CX, the 1.5L D15Z1 for the VX and the 1.6L D16Z6 used on the EX and Si.the 6th Gen Civics (1996-2000) had four engine choices as well: the 1.6L D16Y7 used on the CX, DX, LX and Value Package, the 1.6L D16Y5 used on the HX, the 1.6L D16Y8 used on the EX and the 1.6L B16A2 used on the Si.