CREATE TABLE table_52148 ("Constructor" TEXT, "Chassis" TEXT, "Engine" TEXT, "Tyre" TEXT, "Driver" TEXT, "Rounds" TEXT)

In rounds 7-13 what engine was featured?
SELECT "Engine" FROM table_52148 WHERE "Rounds" = '7-13'
SELECT "Engine" FROM "table_52148" WHERE "Rounds" = '7-13'