Originally Posted by jchammond

You have a 17’ Nismo; so Jon probably tuned in 5th gear (1:1) because of 3.92 rear differential ratio
1:1 will always yield a more accurate Dyno results.
The 4th gear pulls on an M/T Z are (1.27:1) & (1.41:1) on A/T Z’s
Though the power on 4th tuned cars is great; it will show less on the paperwork,actual rwhp/TQ of the cars
Also, I see yours made power to 7700rpm’s
Nice cold weather & good air quality involvement

Also, Jon is really good with UpRev & there could possibly be some updates in software, or just his knowledge over the years has increased