man....some people have really done well on the 18 inch tires. I have run a few 1.65 to 1.70 sixties, but nothing consistent. The tires are great as long as the driver has matching skills.
I think Cudaman ran a 1.49 60 on some as well. I like them, just need some more experience launching the car. They also seem to last pretty good. I have put probably 50 passes on mine and I bet they have 30 to 40 more left. They don't require heavy burnouts IMO, just ONE GOOD INITIAL burnout and after that mainly just cleaning them off.