How many capacities are possible for the 1.6 Duratec model/engine?
CREATE TABLE "engines_and_transmissions" (
  "model_engine" text,
  "capacity" text,
  "cylinders_valves" text,
  "power_rpm" text,
  "torque_nm_rpm" text
);
SELECT COUNT("capacity") FROM "engines_and_transmissions" WHERE "model_engine"='1.6 Duratec';