CREATE TABLE table_50946 ("Rider" TEXT, "Manufacturer" TEXT, "Laps" FLOAT, "Time" TEXT, "Grid" FLOAT)

What is the highest number of Laps that have a Time of +18.366, and a Grid lower than 13?
SELECT MAX("Laps") FROM table_50946 WHERE "Grid" < '13' AND "Time" = '+18.366'
SELECT MAX("Laps") FROM "table_50946" WHERE "Grid" < '13' AND "Time" = '+18.366'