I'm sure this has been beat to death on this site, but I'm new. Do I really need to use premium gas in my '04 max?

 

yes yes yes

 

I use 87 octane and get 27 mpg

 

Whatever you use, the ecu will adjust to it....91 is premium, it says use premium for max performance...Ive always used 93 just because its about the same price as 91. I have heard that you lose something like 20hp using 87...dont quote me on this though.

 

The manual says the engine was designed for 87, but under the gas cap, it says use "premium" I haven't noticed any knock or pinging with 87, and the power doesn't feel bad either. I seriously doubt its a loss of 20hp, ive read other threads where people comparing both, notice no difference. If the car is designed for 87 octane and the engineers say it can run off it, why waste the extra $$ for 93 octane unless you plan on being Andretti.

 

Premium is the way to go. No knocking no dirty valve deposits no concerns.

 

Thanks guys for your opinions. I will take them all into consideration. Wayne

 

Performance will not suffer too much with the differneces in octane.

However, disassemble a motor with 100k miles on it that ran 93 octane all along and compare it to the inside of a motor that ran cheap gas with the lowest octane rating and you will be surprised how much cleaner the motor that was run with 93 octane will be.

That alone is reason enough for me to use the higher octane fuel. Amoco premium is the only gas I have ever used on any of my vehicles.

 

Performance will suffer w/ less octane because the knock sensor will adjust the timing to reduce knocks, thus reduce power. After I put the G35 ECU on, my car started knocking at WOT because of the more advanced timimg.

The MPG number depends largely on how you drive, little on octane number.

 

Did you read these? There is so much more info in those three threads alone:

http://forums.maxima.org/showthread.php?t=450870
http://forums.maxima.org/showthread.php?t=390733
http://forums.maxima.org/showthread.php?t=418005

 

The manual says to use 87 octane as someone mentioned above and thats what I have been using for almost 6 months now.

 

I did'nt know you put the G35 ECU in?! can u tell a big difference?

 

I'm using it while Technosquare is cracking my ECU. More power, but not fully compatible.

 

And Im using a modifided 350Z ECU in mine and its fabulous. My ECU has been cracked and Ill get it too from Technosquare

 

Thanks for including one of my threads in your list. On that first thread, check out my comments and those by SteVTEC. But you left my best thread on Octane off of your list. It is for those who don't think they know all they need to know about Octane, and it can get somewhat technical -- but that is what Octane is = technical.

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

Guess I should also acknowledge that I am one who burns the cheapest branded gasoline I can find (I stay away from unbranded gasolines). Here in Colorado that is 85 octane regular. At times on the road it is 89 octane mid-grade. If I were racing or doing a dino test of my car, I would start using premium at least 300 miles before asking for the absolute maximum performance from my VQ engine. As I don't do either, I don't pay for premium performance that I don't use or need.

 

I notice a signifigant difference in performance when I use 93 rather than 87. I almost always use 93. I get better gas mileage with it.

 

SteVTEC, whose technical education is more recent than mine, believes you will get better gas mileage burning premium around town and regular on the open highway. Suspect you are seeing the around town portion of that driving. Steve also points out that it takes about 300 miles for your VQ to fully adjust to a change in fuel octane. I can not confirm any of his positions, but he does seem to know what he is talking about, and generally agrees with me on all issues where I know something about the topic.

 

I have always used 89 since I bought it, though premium is recommended as per the gas lid.

 

I use premium for the fact that is better or the car and I will never understand why people go around looking forgas 5 cents cheaper. If you had a completely empty tank and got premium instead of regular the difference is roughly $3.00 per fill up....i mean for $3.00 extra for 20 gallons i will always use better gas. and even if you found somewhere cheaper(i.e. 5 cents) you are saving a whopping $1.00.

 

i always use 93...i know a place that has 100 octane my friend with his altima se-r has used it and said its ridiculous but has to be mixed with 93...cant use full 100.