Ok, mot handbook says tread depth has to be over 1.6mm of tread on the central 3/4.

If the section marked "445" in the picture is worn below 1.6mm is this a pass or a fail? Assuming the measurement is taken from the central 3/4 of tread?

The tyre is a goodyear nct5, alot of good years are similar were the grooves on the outer & inner sections have grooves not as deep as the centre. i.e. the centre of tread will be 2.5mm (pass) but the blocks on the edge is 1.5mm.

I have heard some testers say 1.6mm ONLY applies to the deepest part of the tread (i.e. centre) but it's a bit unclear in the manual.

Any views?