2024 CO CDL Practice Test: Class A - Test 6 Based on 2024 CO CDL Handbook 30. How much tread should be in every major groove of a front tire? A 2/32 B 1/32 C 4/32 Grade More 30/30 Progress 0 Errors Restart Grade Grade Class A - Test 6 Back to Test List Class A - Test 5 Class A - Test 7 Challenge Library 12 More CO CDL Practice Tests 7 Class A - Test 7 8 Class A - Test 8 9 Class B - Test 10 Class B - Test 2 11 Class B - Test 3 12 Class B - Test 4 13 Class B - Test 5 14 Class B - Test 6 15 Class B - Test 7 16 HazMat - Test