The 2019 Honda Civic Si is available as a 4-door, 5-seat sedan. Starting at $24,300, the 2019 Honda Civic Si w/Summer Tires (DISC) Sedan is powered by a 1.5L , 4 -cylinder engine mated to a manual transmission that returns an EPA estimated 28-mpg in the city and 38-mpg on the highway. The top of the line 2019HondaCivic SiCoupe , priced at $ 24,300 , is powered by a 1.5L , 4 - cylinder engine mated to a manual transmission that returns an EPA estimated 28-mpg in the city and 38-mpg on the highway.