I've had my '04 5AT for about two weeks now. I've never been able to enter manual shift mode (that is, move the selector from D to the manual shift gate) in 5th gear - the highest it enters manual shift mode is 4th gear - I'm pretty sure its actually downshifting from 5th to fourth when I enter manual shift mode from a high enough speed. Of course I can upshift back to 5th gear, but if the car's already in 5th when I enter manual shift mode, why would it downshift to 4th? I'm wondering if this is my car, my imagination, or if this is how its supposed to be?

 

The 4th gear is the 1:1 gear so its a pretty safe gear while giving you decent pickup. 5th gear is overdrive so the manumatic will go to 4th gear automatically when you are driving most of the time (unless you are going slow). It will never go into 5th in manumatic automatically.

04 Coupe Auto/DG/Prem/Nav/Perf

 

Totally normal. It will always downshift to 4th if you are in 5th and switch to MM.

2004 Coupe, 5AT, Twilight blue / Willow int, K&N Typhoon CAI, Hyper Grounding Kit, Mtek Xenon Fog/High, Clear corners, Hypers, 18's, Aero, tint, Premium, Val 1.

 

I guess Infiniti reasoned that when someone switches to MM mode that they are looking to shift in a sportier manner than normal. So it puts you in a gear more suited for sportier driving. It is easier to shift to 3rd or second from 4th that it is from 5th. You can double downshift (have to be very quick), but I havge never been able to triple downshift.

2003.5 G35C 5AT
Premium Package
Tire/Wheel Package
K&N Filter, Z-Tube, EGK