Hi there
For me:-
15s - A nippy car that don't hang around
14s - Quite fast territory, certainly a car to make you grin - S2000 performance
13s - Getting pretty damn quick now, impressive
12s - Stupidly fast, even more so if its a road car
11s - Crazy stupid fast and normally limited to the fastest supercars or drag cars
10s - Not many road cars can do this, apart from very heavily modified ones
Sub 10s - Normally not road cars or cars that have had more spent on mods than you can buy a house for.
I am not into quarter mile racing as I never really have found the excitment in launching a car hard of the mark and having no sympathy for the mechanicals.
Needless to say guys in the US running the same setup, saleen supercharger, blower, exhaust as myself generally see around
11.5s @ 120mph on road tyres. Those who set the suspension up for drag racing specifically and fit sticky rubber have got into 10s area with the same kind of power as mine is producing with 130mph terminals.
Sometimes you get fast 1/4 mile cars due to their gearing but on road performance can be slow as they run out of top end puff.