Tight on tyres

[SpidermanBrummie]

My car tyres width is 245mm (bloody expensive)

I'm told you need to ensure that 3/4 of a tyre must be 1.6 mm (245/8=30.6mm)

I'm taking measurements of a new set of tyres from the centre which is roughly 7-8mm

and then I'm taking measurements 30mm in from either side which is coming in at 5.5mm

is that the correct method to measure as this means I'm only getting 4mm out of a set of tyres.

Maybe any MOT testers can help?

Should I be measuring grooves "roughly" in the 3/4 centre of tyres?

[E-bmw]

if your tyres are wearing more towards the edges than in the middle your tyres could be under inflated.

The rule is:

1.6mm for more that 3/4 of the tyre width & visible tread for the remainder.

In practice you can only measure the tread depth at the grooves (for obvious reasons) so you just need to work to the closest groove to 3/4 width of the tyre.

[SpidermanBrummie]

For the sake of clarity and my OCD...

The tyres are brand new. If I measure 30mm from either side it doesn't reach the grooves. I have been measuring the area at the edge(ish) of the tyre.

If I've understood you correctly I can only get a realistic reading by measuring the grooves that run the full circumference of the tyre.

This makes more sense to me