Thanks guys. I get it now, but I do wonder if this is all a bit of smoke and mirrors. Is there really a need to make that many variations of every single tyre size? And can anyone tell the difference?

The tyre manufacturers want the vehicle manufacturers to use their products. The vehicle manufacturers have specific requirements for ride, handling, noise etc and therefore in order get the contract, the tyre manufacturers have to tweak their design accordingly.

Sometimes the differences are very subtle, but other times less so. Mum's Beetle Cabrio takes 225 45 17 - a really common size. When I did some work on it recently I discovered it had Conti SportContact 5 MO on the front and AO on the back (tyre fitters who don't know or care again). One of the front tyres was damaged, but when I looked at them closely I could see not only differences in the sidewall, but also in the tread pattern itself so I specifically sought out an MO tyre to replace the damaged one. When I had the tyres dismounted to refurb the wheels I could definitely feel a difference in the strength of the sidewalls between them - the Audi version was harder. This would be slightly noisier, but would turn-in better. Given that the Beetle is front engined I ended up putting the AO tyres on the front where the weight was, and the MO on the rear, which seemed to suit it because Mum reported back that it drove much nicer afterwards :) Of course that might have been to do with me spending a couple of hundred hours giving it 'the treatment'! It'll get Goodyears next instead of Contis though as the sidewalls are softer again so are quieter and ride much nicer overall.

You’re better than Google, Michaela! Thanks again