Question Tread depth in the major grooves on a front tire should be at least: Answers 1/32 of an inch. 2/32 of an inch. 4/32 of an inch. 3/4 of an inch. Explanation Tires need to have at least 4/32 of an inch of tread depth in every major groove on the front tires, and at least 2/32 of an inch of tread depth on other tires. Take a FREE Practice Test Now This questions appears in the following tests: Tennessee Knowledge Test Class A , Utah Knowledge Test Class A ,