I read the article. If you paid attention to all the preliminary parts in which the author explained the complex computer program (at the University of Michigan, I believe), there are tons of variables the engineers have to enter to make this work. The MT author admitted to not having every last bit of data necessary, so they had to guess on some things.
One key item they didn't have was the Mustang's drag coefficient, which they said Ford won't release. It must be gosh-awful, as B-A-Better Person has long suggested. And because they didn't have the Mustang's aero number, all of the acceleration figures reflect what would happen in the airless environment of cyberspace. So whereas the 0-60 times might be close to real-world figures, the number for the quarter-mile aren't going to be true-to-life.