Eric, I've got a 4.437 in the NX and I *never* run out of gear. Never at WGI, never at Road Atlanta. Yup, I use fifth...gear ratios 3.333, 1.826, 1.286, 0.975, 0.756.

At WGI I shift into fifth just as I crest the top of the esses, and max RPM there is 7200.