All season tyre choices

[pmknowles]

Front & back is fine. It's mixing on the same axle that's bad.

No, if you have one set of tyres which is gripping better than the other you can induce 'snaking' in the vehicle - check out HonestJohn and others

 

[securespark]

And more grippy at the rear is ok.

In the 80s and 90s, I used to put the deeper tread/ new rubber on the front. No tyre fitter told me different.

In the 2000s, I was told by tyre fitters it is recommended to fit the new or deeper tread on the rear to minimise the risk of oversteer (where the back end loses grip).

Oversteer is a lot harder to control than understeer, hence why new tyres are fitted to the back regardless of drive (front, rear, 4 WD).

If tyres on the front with less grip were to understeer (where the front end loses its grip), it would be less dangerous and easier to control.