CREATE TABLE table_80210 ("Year" FLOAT, "Entrant" CLOB, "Chassis" CLOB, "Engine" CLOB, "Points" FLOAT)

What chassis did the porsche flat-4 use before 1958?
SELECT "Chassis" FROM table_80210 WHERE "Engine" = 'porsche flat-4' AND "Year" < '1958'
SELECT "Chassis" FROM "table_80210" WHERE "Engine" = 'porsche flat-4' AND "Year" < '1958'