CREATE TABLE table_71846 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Points" TEXT)

Which year has has a Engine of maserati straight-6?
SELECT COUNT("Year") FROM table_71846 WHERE "Engine" = 'maserati straight-6'
SELECT COUNT("Year") FROM "table_71846" WHERE "Engine" = 'maserati straight-6'