The best mpg since I bought my new max has been 19 mpg mix driving. Still has less than 1500 miles so I feel it will improve around the 6000 mile mark...

 

Premium fuel is more difficult to burn (yes, you heard that right.) The onboard computer has an easier time if it can control when the ignition of the fuel is, most of the time that isn't a problem but under high stress sometimes the fuel will pre-ignite and that causes knocking and reduced power/ efficiency.

 

maybe your doing a lotta city driving.

I once did 550 miles on a full tank but that was non stop high way driving.

 

Since everybody is comparing regular v.s premium, I wonder how it would be like if we added jet fuel to our Maximas

 

I just put 93 in, screw it.

 

You must not be from california then. I wonder if there is much difference from 91 to 93 octane on the butt dyno.

 

In cars whose fuel system is set up for 93 octane, there could be a performance difference. But in the 7th gen Maxima, whose fuel system is designed/set up for 91 octane, the car will perform the same on both 91 and 93. If the butt says otherwise, it is lying through its crack.

 

Around what was your average speed for 550 on a tank

 

Would not run, jet fuel is mostly kerosene.

 

Well there goes my Chemistry. I'm doomed this spring semester

 

Interesting thread.... just skimmed through it out of curiosity.

There is some good info posted here, and bad info as well. The ones that are putting E85 in their non flex fuel cars are just asking for it...

The federally mandated ethanol blended fuel is also misleading since most people don't quite understand it. At the pump, it clearly states "up to 10% ethanol" and is not E10, which is always 10%. When it says, "up to 10% ethanol", it might not have the full 10%. It could have 8%, or 5%, or even less, but no more than 10% ethanol.

Oh, and the one post about diesel fuel and it's octane rating had the lulz going for it, since diesel fuel isn't measured in octane, but rather cetane. I got a good laugh out of that. Diesel fuel around here has a cetane rating of 45.

If the car says premium fuel only, then that's what I use. If it says premium fuel recommended for maximum performance (like my 5th gen) I use the premium. My car with 168 thousand miles does not like regular 87 when I accelerate. Just cruising around in granny mode I cannot tell a difference. Only when I get on it is when regular 87 makes it feel sluggish.

Here in Florida, I have only seen 93 octane. The 91 octane is considered to be a "minimum" or "standard" octane rating for premium fuel. Getting 92 or 93 octane is just an added bonus if you have a modded car or especially a boosted one.

When I had my supercharged Grand Prix GTP, it said premium fuel only, so that's what I used, especially since it's boosted. Having an extra 2 octane (93 vs 91) was an added bonus so when I replaced the supercharger with a ported one, I also had a smaller pulley put on for increased boost. Since I had those extra 2 octane points, I was able to get away with the extra boost on the stock computer I had at that time without having to worry about knock retard reducing power under full throttle. ZZ Performance sells an upgraded computer for increased performance for that car, and there was an optional 93 octane on the order checklist, so I ordered me a computer with the 93 option to give the car more aggressive computer tuning. I could have stepped down a size or two smaller on the pulley, but I kept the one I had to give me a buffer zone instead of running it on the edge of ZZP's recommendations.

I almost exclusively use Shell V Power, but if I need gas and a Shell station isn't anywhere around, I will use Cheveron or BP since it's actually Amoco Ultimate. I prefer these fuels since they have more cleaning agents compared to "bargain" gas. Even with 168 thousand miles on my car, I have yet to experience any pinging using these higher quality fuels.

 

Nissan tech said it makes no difference 87 vs 91.....just wasting your money. Hard to believe reading this thread.

 

Your Nissan tech is WRONG. Some folks here feel their car is runnning OK on regular, as long as they drive conservatively. But many here who tried regular noticed the difference immediately. Some found their car would barely run on regular, and would never try regular again.

It is a shame dealers are having to hire such uninformed incompetent folks in their service department. Thank goodness my dealer has very knowledgable service folks.

But I learned about sixty years ago to take the word of anyone in any service department with a grain of salt. I always do my own testing, and found my car runs beautifully on 89 (midgrade), 91 (premium in some states) and 93 (premium is other states).

After reading on this site a few years ago that one poster was running regular just fine, I did try putting in a half tank of regular, drove around the adjacent parking lot for a few minutes, and found the engine was not running well. When I tried to climb the hill at the back of the lot, my engine pinged, so I circled right back to the pumps and filled the last half of the tank with premium.

I now use midgrade exclusively. My car runs beautifully on midgrade, and the MPG is the same for 89, 91 and 93 octane. As it should be, since octane is not directly related to MPG.

If you want to run regular, you should have bought a car set up to run on regular. The 7th gen Maxima was never intended to run on regular.

 

^--> AMEN brother

 

Never listen to a tech

You can put whatever is the cheapest into any car, but what makes the difference in the long run, is better fuel and oil, if you ever wonder why cars with relatively low miles look and sound like crap, its the small things that make a difference.

 

I use either 91 or 93 depends on the gas station

 

I used regular for my first fuel up on my maxima and then seen that it said premium so just started using premium ever since then

 

I always use premium. You can feel the difference in power.

 

Feel sorry for those folks that buy/have purchased previous rental Max's since the 3.5 in 02.......You know they were all run on 87.....heck i put 87 in the rental Max's I get on business, ooops. 87 just doesnt do 3.5 Maxima's well at all.

 

I use regular in winter as it does not make much of a difference...I can tell that the car doesn't run as well but it runs fine and the difference in Canada is high. However in the warmer months I use 93 - 94 octane that we get at Petro-Canada and the car goes like it's using rocket fuel...it's a very dramatic difference! My car is not stock...CAI, UDP, ECU, etc....

 

regular 87 seems to work fine

 

I go back and forth from 93 to 87. I average 22 mpg. I would like alot more.

 

MPG should not be related to octane. 22 MPG is good for this heavy car with a strong engine, unless it is all freeway driving, where you should get between 27 and 30 MPG.

I would think your car would do better if you simply used midgrade (89 octane). I always use premium gas the first 18 months with every Maxima I have ever owned (every gen but the first, and more than one Maxima of several gens), recording exactly how everything is doing. Then I switch to midgrade, and measure everything again. I have never measured any performance change between premium and midgrade.

The real advantage of using midgrade instead of switching between premium and regular is that the fuel system is not always having to adjust between extreme octanes. This allows the engine to operate more efficiently 100% of the time.

 

I use either 91 or 93 tend to average around 23.5MPG

 

put in 93, thats all mine sips and it is slightly more expensive per fill up, but you notice it when you step on the gas, and youll get better gas mileage to boot.

 

I will post something I have posted on Maxima.org fairly frequently over the last decade or so. It always draws doubt and criticism, but then an engineer or scientist among us will invariably give us a reference to articles saying exactly the same thing, and even explaining why this is true.

Premium should usually get better gas mileage in the 7th gen than regular, because this car was never intended to run on regular. But premium (93 or 91 octane) will not get better gas mileage than midgrade (89 octane), because, as long as the octane is close to the level the fuel system is set up for (91 octane), the fuel efficiency will not change.

Although urban rumors to the contrary abound, closely controlled lab tests prove that, as long as the fuel is of an octane close to that the car is set up to run on, octane variations do not affect fuel efficiency. This has been proven many times in many test labs over the last fifty years.

Originally, I had my doubts. But after decades of checking this myself in many different Maxima generations, and reading scientific articles explaining why octane is not directly related to fuel economy, I now know the scientists are correct.

The average driver cannot measure fuel effiency to any EXACT degree. Because of variations beyond the control of average drivers (I have seen 46 such variations listed), anything less than several dozen tankfuls of gas carefully dispensed from the exact same gas pump to the exact same level of the filler tube at the exact same gas station with the car sitting in the exact same position facing the exact same direction and at the exact same slant, in the exact same temperature at the exact same relative humidity, with the exact same winds in the exact same direction, with the exact same psi in all tires, the exact same alignment, the exact same tread depth, the exact same weight in the car, the exact same load balance on the car, driven in the exact same lane of the exact same road in the exact same traffic at the exact same speed using the exact same accelleration and the exact same decelleration and the exact same braking, etc, etc, will prove nothing.

We can get a good idea of our approximate MPG, but not to an exact level.

What premium DOES give us (and why Nissan recommends premium) is slightly improved performance. If I were making elapsed time runs, premium is the ONLY gas to be considered. I would suspect premium would barely edge out midgrade in elapsed time runs, which is actually a big deal for mag testers and track folks. And I suspect premium would more decisively beat regular gas in elapsed time runs. But will premium get better MPG than midgrade in daily driving? No. It may seem like we get better MPG using premium over midgrade, but we don't. Over regular? Possibly, as 87 is not in the octane range this car is intended to use.

But then we know there are many folks that will go with 'seat-of-the-pants' impressions or attempted 'self-measurements' over scientific tests every day of the week. Such is life.

 

My friend's 1999 Maxima (purchased sorta new as a demo car) has never in it's ~250,000 miles seen anything other than 87 AKI. With routine maintenance, it still runs as well as the day she got it.

My 2010 SV has seen 91 or 93 AKI on 99% of fillups. The few times I have put 87 AKI in the tank, I couldn't tell a bit of difference. I'll be experimenting and only puting 87 AKI in the tank for about a month to see what happens.

Higher octane is only beneficial at high-loads. Casual city driving and gentle highway driving will see no benefit from premium fuel.

Late,
Trav

 

There is, of course, some truth in what you say, but I feel that may be too generalized a statement. Remember that the 7th gen has a higher compression ratio than your friend's '99 Maxima, which means it needs a higher octane.

As for your experiment with regular, remember that when you took on a tank of regular, there were probably still three or four gallons of 93 octane left in the tank (the 7th gen guage shows empty with around 4 gallons left, and that is when we should refill), which raised the octane level to around 88.

Several here who tried 87 octane on a regular basis and drove gently seemed to do OK, while others here found their engine had trouble trying to run on regular.

Remember, Nissan tells us right in the Owner's Manual that, should we find ourselves in a situation where regular is the only gas available, to put in only enough gas to get the car to a higher octane gas, and to do no aggressive driving on the way. Maybe they have a reason to tell us this?

 

I can say from experience that the car runs better on higher octane then on regular. I ran it on a few tank fulls of regular and it ran like it was missing a cylinder or 2. I've since ran it on highest octane available and definitely feel the difference. When I need to punch it it responds crisply. I know now they keep high octane in the tank at the dealer for test drives because it ran as it did when I test drove my car before purchasing it.

 

I ran regular once and it totally lost its punch... I also saw about 2 mpg less... Therefore the additional cost for premium really evens out due to the mpg gain vs regular... I will never put regular in her again...

 

No....my manual doesn't say that at all. When I had my Z, the manual did state exactly that. For the Maxima, Nissan just says that "you may notice a decrease in performance."

 

Correct... I read my manual cover to cover never said anything about finding another gas station etc...

 

Then Nissan has changed the wording since my 7th gen '09 came out. In retrospect, I seem to recall someone saying Nissan had softened their insistence on premium starting around 2010.

Rather than wake my wife by turning off both our security systems (this is not a silent procedure), I will wait until tommorow and bring my owners manual in and quote the wording in the '09 manual. I did quote that portion of the manual here fairly frequently back in 2009, but that was a long time ago . . .


NOTE - I did post the promised warnings from my '09 Owner's manual to this thread at 8:50 PM Thursday night (see below).

 

Your arguments about mid-grade convinced me to try a tank this morning. I have always been a proponent of premium as I have modded my car a bit. I am scheduled to have a full UpRev dyno tune next month and will probably run premium for a couple of tanks leading up to that, but I am game for trying the mid-grade for now. I do notice a lack in performance when I have run regular in the Max, so if the car is not lagging with mid, I'm cool with it. 15-cents/gallon savings is just a bonus!

 

I guess my biggest problem with midgrade is that it mixes regular with premium rather than a stand alone fuel. I am one of those people that think everyone is trying to screw me and do not trust the mix ratio or have know way of seeing it myself therefore it worth the few extra cents...

Just for the record I hate the fact that my Nissan suggests premium fuel. When I had my Lincoln LS it required premium fuel but I always used regular. It would ping under hard acceleration but the car was such a dog compared to my current Maxima it didnt matter to me. I didnt notice any difference from premium to regular in that car. I do notice it with the Max thats why I stay with Premium. Being that my car is still relatively new (3 months old 2100 miles) I am sure the feeling may wear off a little and as fuel prices sky rocket I will be kicking myself in the but... On the other hand I am saving over $100 a month on fuel compared to my Armada which I traded in for the max so even with the added expense of premium I am still way ahead of the game...

The debate continues....

 

Regardless the car and manual says nothing less than 91 if you dont want to put premium in than you shouldnt have bought the car its pretty simple I think.

 

I think you will find that, although these 7th gens do not peform as well with regular as they do with premium, your car will perform exactly the same with midgrade as it does with premium.

You are lucky the price near you is only 15 cents between grades. Around where I live, midgrade is almost always twenty cents more than regular, and premium is forty cents more than regular.

 

Here in Georgia, stations are tested regularly, including fuel taken from each pump and tested for octane. Violations are fairly stiffly fined. I think the proof of the pudding is that my Maximas have always run extremely well on midgrade, but the few times I tried regular, there was definite pinging with accelleration. I do stick with major brands.

This subject is meaningful for me in that I live in an area where midgrade almost always costs twenty cents more than regular and premium costs forty cents more than regular. An eighteen gallon fillup of midgrade saves me $3.60 over premium. $3.60 is not much money, and I can easily afford the premium. But since my car runs exactly the same with midgrade, I simply go with midgrade, and add the savings to my investment funds.

I agree with you that Nissan would be wise to build cars that would run on regular with no major performance drawbacks. They need to realize that the days of 18 cent gas are gone. I paid 18 cents per gallon for premium gas at the local government exchange for my '66 Oldsmobile Delta 88 in 1966. I won't tell what I paid for gas for my '49 Studebaker over sixty years ago, as that would make some folks here long for the 'good old days.'

Good move on the Armada. The days of the Armada are over. And that is both the Spanish Armada fleet and the Nissan Armada boat.

 

Quote:
Originally Posted by jjklongisland
Correct... I read my manual cover to cover never said anything about finding another gas station etc...

********************

Posted by lightonthehill last night:

Then Nissan has changed the wording since my 7th gen '09 came out. In retrospect, I seem to recall someone saying Nissan had softened their insistence on premium starting around 2010.

Rather than wake my wife by turning off both our security systems (this is not a silent procedure), I will wait until tommorow and bring my owners manual in and quote the wording in the '09 manual. I did quote that portion of the manual here fairly frequently back in 2009, but that was a long time ago . . .

*******************************************

Posted by lightonthehill tonight:


Well, I promised to post the wording of the '09 Maxima Owner's Manual. Here it is from page 9.3:

FUEL RECOMMENDATION

Use premium unleaded fuel with an octane rating of at least 91 AKI (Anti-Knock Index)number (Research octane number 96).

If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of 87 AKI (Anti-Knock Index) number (Research octane number 91) can be used, but only under the following precautions:

Have the fuel tank filled only partially with unleaded regular gasoline, and fill up with unleaded premium as soon as possible.

Avoid full throttle driving and abrupt accelleration.

-----------

That warning has obviously been deleted from Maxima Owner's Manuals of the last few model years, but still applies to the earlier 7th gens. Also, among the pages of discussion regarding fuel in my '09 Maxima Owner's Manual was this:

CAUTION

Using a fuel other than specified could adversely affect the emission control system, and may also affect the warranty coverage.

----------

But enough on fuel. I intend to keep up my long habit of running my Maxima on premium the first 18 months, carefully measuring things like MPG, then switching to midgrade the remainder of the time I own the car, again measuring things to confirm the midgrade performs exactly as the premium did for my type of driving.

 

THAT is kind of wild....I wasn't under the impression that there were any differences, mechanically, between the 09 and 10 models. Perhaps there are. The 370Z DOES state the same thing as the 2009 Maxima manuals. The 370Z is somewhat different as it is producing 89hp/L and the Max is 82hp/L.

I did run 87 octane in the Z for a couple tanks....I DID notice a decrease in performance and DID NOT notice any pinging at all.

Late,
Trav