And there's a very good reason why.
The Nurburgring has become the go-to place for proving a car's high-performance worth. Whether it's the Nissan GT-R or a Porsche 911 GT3, the Ring is also the ideal locale to perform suspension refinement and the like. At the same, however, any new high-performance sports car has to seemingly prove itself today on that German track. The Mustang Shelby GT500 is no exception, but unlike those aforementioned cars, Ford isn't interested in getting involved with these petit lap-time battles.
Jamal Hameedi, Ford's Global Performance Vehicle Chief Engineer, was recently asked by SVTPerformance.com, an SVT fan site, on why his company hasn't released the official Ring lap time for the GT500. It's a fair question but Hameedi had this to say: Our (my) view is that there is no such thing as an official manufacturer Ring time. The reason we test at the Ring is because it is a fantastic venue for doing vehicle dynamics work...I think it's really important that performance cars be judged against one another on the track - but the comparisons really need to be on the same day by a professional driver."
To summarize: there's simply no official standardized method to record track times. Therefore it's impossible to compare cars directly against one another. Hameedi points out the GT500 has sold just fine without its Ring lap times officially published. Once there is a standard for measuring lap times, Hameedi said he and his crew will be the first to sign up.