Even though a 10.8 @ 126 is the quickest and fastest of the three major US Magazines these numbers still are slow. Independent drag strip results are better with a 10.68 @ 128 pass on the dragstrip. Car and Driver, Road and Track, and MotorTrend all get a result with the more powerful 991 Turbo S that is closer to the standard 991 Turbo. The standard car at PBIR (Palm Beach International Raceway) in Florida ran 10.9 @ 126.
So what is the deal? We really do not know. Maybe the cars pull timing due to aggressive software. It would explain why dyno results seem to vary greatly pull to pull. The spread shown on an all wheel drive Dynojet is up to 30 wheel horsepower and torque can change by almost 60 lb-ft. Heat soak, software, timing, whatever it may be something is causing inconsistent performance with the 991 Turbo and Turbo S.