Maruti Zen and Esteem have different engines. The Zen comes with a smaller 993 cc 4-cylinder unit, producing 58 BHP @ 6000 rpm and 79 NM @ 4500 rpm. It comes with a 5-speed manual gearbox and returns a mileage of 14 kmpl. On the other hand, the Esteem had a bigger 1298 cc , 4-cylinder engine producing 84 BHP @ 6000 rpm and 110 NM @ 4500 rpm. It also comes with a 5-speed gearbox but produces much more power on the same rpm. It returns a mileage of 13 kmpl and comes with a bigger boot space being a sedan. Both the rides have been discontinued as Alto K10 and Dzire petrol offers the same fun with much more power and refined riding experience.