Final answer:
The required minimum thread depth for front tires is typically 2/32 inch, though it's always best to check specific legal requirements according to your location.
Step-by-step explanation:
The question is about the minimum required thread depth on every major groove in the front tires of a vehicle. When it comes to safety and performance of tires, having the correct thread depth is critical. Although there is an older 'rule of thumb' which was 5 side-to-side and 7-8 deep, more recent suggestions state the need for as much as 8 diameters side-to-side and 15 diameters deep. However, since the question seems to be concerned with legal safety standards, it is common to require at least 2/32 inch thread depth for front tires to pass a safety inspection. Always ensure to check the specific legal requirements for your jurisdiction as they can vary.