CREATE TABLE table_68886 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Pts." FLOAT)

What is the highest number of points the cosworth straight-4 engine scored?
SELECT MAX("Pts.") FROM table_68886 WHERE "Engine" = 'cosworth straight-4'
SELECT MAX("Pts.") FROM "table_68886" WHERE "Engine" = 'cosworth straight-4'