My slow 12.7@112mph has nothing to do with my rear tyres being worn Nankangs.
With everything running properly and a decent driver it should be mid 11's actually.
Actually it's a combination of my clutch fluid lines needing a bleed and only having the car for 4mths.
For all I know my rear Nankangs may have done 20,000km. I certainly wouldnt put new Kankangs on my car (i'd use Bridgestone, Michelin or Pirelli) but they are fine for now until they need replacing towards the end of this year.