TSQL Minimum of Multiple Columns
SELECT TOP 10 *, (SELECT MIN(tread) FROM (VALUES(tire_tread_1),(tire_tread_2),(tire_tread_3), (tire_tread_4)) x(tread)) MinTread FROM #myTable
SELECT TOP 10 *, (SELECT MIN(tread) FROM (VALUES(tire_tread_1),(tire_tread_2),(tire_tread_3), (tire_tread_4)) x(tread)) MinTread FROM #myTable