I think Nissan knew the VG30DE/TT's would be abused. 5W20 was not allowed, and 5W30 was only allowed under light driving below 60F with 10W30 and 10W40 recommended in temps 60F and above (this verbiage was also on a sticker under the Z32 hoods). There was also an addendum in the 1989-1996 Z32 FSM that said to use 10W40-20W50 for high speed driving and racing. When I started following the Z33 forums, they all were using W40s due to better uoa results.
Originally Posted by hallstevenson
The FSM for my VQ35HR specs 5W-30. To my knowledge, the FSM is not region-specific either. There's NO climate range referenced at all.
Originally Posted by aquariuscsm
...and the FSM's always said never to use a 5W in anything but below freezing temps (the CAFE po-po haha :P ).