CREATE TABLE table_204_808 (id DECIMAL, "team" TEXT, "no" DECIMAL, "driver" TEXT, "class" TEXT, "chassis" TEXT, "engine" TEXT)

which engine was used the most by teams this season ?
SELECT "engine" FROM table_204_808 GROUP BY "engine" ORDER BY COUNT("team") DESC LIMIT 1
SELECT "engine" FROM "table_204_808" GROUP BY "engine" ORDER BY COUNT("team") DESC NULLS LAST LIMIT 1