It's always 4th gear. Because you run the car threw the gears and set it at 2000rpm's in 4th. The power band of the car can be reach to full potential in forth do to redline and MPH with in that gear vise 3rd gear. Which at a 7200rpm redline, tops out at 110mph and your going to run into a rev limiter fuel cut off with in that run causing lose of power. While 4th gear will let you run from that 2000rpm to 7200rpm reaching any speed under 143mph. Which any turbo can reach full boost because your going from 4th gear at 2000rpm's which is 40mph to 7200rpm's which is the 143, giving you over 100 miles per hour of clearance before shut down.
