Gasoline. Regular or premium? That 'tis the question.

[GAU-8]

I just got out of a Saturn Ion Redline. 2 liter 4 banger with an Eaton M62 on top. Dabbled in tuning it myself. That had two octane tables. I still preferred high octane though. Car seemed to run 1000% better with it.

[Poyzinous]

Its because Nissan engineers want people to have all 330hp. Some of the older VQ35 motors could run on both just fine on regular, but they run better on premium. The newer models are labeled 'premium fuel only' because maybe they were mapped out just for 90+ octane.

[smockers83]

nice info bud!! so according to your table, our cars can run 100 octane safely without a tune correct? i always figured that but wanted confirmation : )

First, thanks. Second, I suppose but also read this sentence from above.

The table of compression ratios and octane levels is based on compression ratios with no engine management system. With an engine management system, the octane levels drop 5-7 points. [3]