The article is light on detail and somewhat ambiguous in its phrasing. "Can hit top speed in 6th" and "can only hit top speed in 6th" are not the same statemen

The article is light on detail and somewhat ambiguous in its phrasing. "Can hit top speed in 6th" and "can only hit top speed in 6th" are not the same statement. If we assume the latter is what they really mean, there is still a second question of whether top speed is engine power limited or not. If the car hits the rev limiter in 6th gear, it may well have enough power to go faster with an ideally chosen 7th gear ratio. But, the included 7th gear ratio may be too tall, so that immediately upon shifting, the engine bogs down to low in its power curve and the car loses speed. If the car hits top speed in the peak of its power curve but below the rev limiter, it is really out of power in 6th and no other gearing can help. Beyond gearing and power, another potential top speed limit is due to aerodynamics and grip. A car can be traction limited at top speed, with the tires starting to slip instead of accelerating the car. But, being a high-end Porsche, it probably develops the down-force required for traction, thereby increasing aerodynamic drag and putting you back into the power-limited regime...