I doubt it that any Civic would have made that milage in the 90's even the Civic Hybrid doesnt make it as that only does 47-50mpg. Most Honda Civics get into the 32mpg range and max out at 40 excluding the hybrids. As you said if that Honda did exist im almost certain they would still make it as it would be a good competitor for they Toyota Prius which does 55-59mpg.