I know the max is supposed to run on 93 octane. But the last 2 tanks I have used 87 and I have no knocking or loss of power and my mileage is better. My routine for daily driving is the same my driving patterns are the same (aggressive) My mileage went from 20 with 93 to 22 with 89 and 24 with 87. I do not use the computer because it hasn't been accurate once, especially est to empty I always have 5 gals left when it reads empty. I also always buy my gas at the same station, it just doesn't make sense to me.

Anyone else notice this?

 

xact opposite here

Kam

 

I have always used 87 octane and get 26 mpg

 

You guys must be driving all highway b/c anything over 22mpg city seem impossible on a Maxima.

 

Another week yet another fuel thread!!!!!

You will not get knocking after just a few tanks of lower octane fuel on a new vehicle. You may never get knocking after years of running lower octane fuel depending on your driving style and driving conditions (all stop-n-go or all highway) or your own fuel additives. Basic engine physics stats that you will get the best fuel ignition (most energy) right at the knock point. Lower octane fuels push the knock point and typically will produce better mpg on the highway. What you sacrifice is performance (and you might not feel it or notice it), it will be lower HP and lower torque.

Depending on you location, you could be coming off the winter grade fuel. So if you had winter grade 93 and non winter grade 87, those numbers would not surprise me. A lot of factors influence mpg, not just “aggressive” driving. Tire pressure, air temperature, dew point, and wind to name a few.

Read the good stuff, I’ll make it easy:

http://forums.maxima.org/showthread.php?t=418005
http://forums.maxima.org/showthread.php?t=450870
http://forums.maxima.org/showthread.php?t=456754
http://forums.maxima.org/showthread.php?t=460054

 

Thanks for the imput. I drive primarily city/rural but mostly stop ang go. You are right that the winter formula may have just changed.

 

Thanks dla for citing 2 of my earlier threads on this topic. But you left off what I consider my best thread on "Octane Number and what it means"

http://forums.maxima.org/showthread.php?t=396716

This thread will tell you all you ever needed to know (and more) about gasoline octane.

All of your points, dla, in this post above are certainly correct.

My belief: if you are not racing or running your Max at WOT frequently, you can save operating costs by burning a lower octane than 91 (the octane the VQ was designed around to provide max performance).

Another point: each engine (including VQs) is slightly different from the same engine in another vehicle. Burn the fuel that works best for your engine and your driving style. That does not have to be 91 octane (or 93 octane), but could well be those premium grades -- if that is your driving style.

 

SilverMax, I thought I had that one (and I agree it is a good one)! Too many links on one thread I guess. I've read your stuff and really appreciate your knowledge on this and other topics. Myself, I’m a sr. mechanical engineer with a good background in math and physics, so I understand the theories behind ic engines, fuel delivery systems and combustions, but do not work in the industry. By no means does it make me an expert on gasoline or octane rating, but want to assist others in their quest for knowledge and understanding.

 

dla,
It is great that you help expand knowledge and understanding. I too am a Mechanical Engineer and worked in the oil industry for 35 years. Yet I still do not consider myself an expert on octane and gasoline combustion. I know enough to provide good information and have sources for when I don't know.

SteVTCH also seems to be a younger person with good knowledge about engines and combustion. Glad to also have you on this site. Knowledge is so much better than belief when it comes to technical matters.