Post by
bmlawless »
https://forums.nicoclub.com/bmlawless-u85265.html
Tue Jan 15, 2008 5:44 pm
I don't know the specifics for the 3.5L in the 2001, but I just went through something similar with my 99 (3.3L). The manual confused me so I had to track down the answer to which fuel I should use.
In my manual, it says to use 87 Anti-knock Index (AKI) or 91 Reasearch Octane Number (RON). When I looked at the pump, it just said "87 Octane Rating" and "(R+M)/2 Method" below it. This of course did not correspond with either of the two numbers in my manual. I asked on another forum and got mixed answers from folks stating that I should use premium and others stating that I could use whatever.
On this other site, there is a knowledge base that allows you to download owner's manuals, service bulletins, and quick-reference guides for your Infiniti vehicles. (If you don't already know, Infinity QX4=Nissan Pathfinder). In the QR guide for my truck, it says "87 Octane". Finally, something that correlated directly to what was on the pump. But why are there three different terms for the type of fuel I should use.
If you go out and Google "anti-knock index" or "research octane number" you will quickly find that in the US, "AKI" and "Octane Rating" are the same. In my case, I have a green light to run 87. Woo Hoo!
So, in case your real question was, "Which fuel should I use because my owner's manual says to use two different types?", the answer is, "Use the one that refers to AKI or Octane Rating."
If your question truly was, "My manual says to use 91, can I use lower?", then I just really wasted everyone's time.