CREATE TABLE table_53713 ("engine name" TEXT, "engine code ( s ) " TEXT, "valvetrain" TEXT, "displacement" TEXT, "max. power at rpm" TEXT, "max. torque at rpm" TEXT)

What is the maximum torque at rpm for the engine with code BMM?
SELECT "max. torque at rpm" FROM table_53713 WHERE "engine code(s)" = 'bmm'
SELECT "max. torque at rpm" FROM "table_53713" WHERE "engine code(s)" = 'bmm'