djtonyg

iTrader: (1)

Same Here!!!

Boxer112

I've put 87 Octane in the car since i purchased it 1700 miles ago. The dealership has even told me i can use 87 octane. They just mentioned that there will not be maximum performance

BBmaxi

iTrader: (1)

I've tried 91 and 87 and didn't feel a difference.

lightonthehill

Elapsed time runs will show a difference.

You are lucky that your 7th gen seems to run OK on 87. Many folks here on the ORG tried 87 and found their Maxima did not run well at all.

I just can't bring myself to put 87 octane in a car which Nissan itself says is set up for optimum performance with 91 octane.

But to each his own . . .

torontobob

Recently got my 07 Maxima, dealer said it was ok to use 87 every so often, like once in 5, but I've stuck to Premium since the day I got it

Addicted

Only premium in mine, same thing for the Altima SER.
Got better consumption with premium than with regular.

maxxxxspeed

It felt different because you WANTED it to feel different..

It's like anytime you put on a cold intake... "wow it's completely different car"... Yeah that 4hp is really making it feel different.

The difference between 87 and 93 is about 3-4hp... Bottom line you can't feel it. It may be smoother running but that's about it.

vlaframboise

Should realy put some premium in it. Me too when I bought mine, the dealer putted reg (87) but, for the last 15 000km I putted ONLY superfuel, which I think is sold in the US by Sunoco. Up here, they sold the 94 in Petro canada, Sunoco and Husky... maybe Mobil would have it

supared

Do some research before you speak maxxxxspeed. You are almost right about the "activation energy piece." Totally wrong about the detergents. Actually, activation energy has more to do with the stroke of a piston and is related to the Ideal Gas Law as it is proportional to the increased pressure of the fuel-air mixture. THe reason the Ideal Gas Law applies is because the fuel-air mixture is a vapor after compression. The increased pressure lowers the temperature at which the gasoline will vaporize/evaporate. What you mean is the higher grade fuel possesses a higher "Heat of Combustion" or higher "Higher Heating value - HHV." This means that more energy is released during combustion. This is leveraged better under heavy compression according to the Ideal Gas Law. Too much compression though will result in detonation, which is why many people opt for water/water-meth injection when they have high comp pistons.

OKAY, FOR THE PROOF THAT FUEL GRADE DOES IMPACT PERFORMANCE OVER THE LIFE OF OWNING A VEHICLE and WHY BRAND NAME GASOLINE IS BETTER:

http://pr.sae.org/saenews/gasadditives.htm
http://www.toptiergas.com/retailers.html

There is a minimum level of detergent required by the EPA. How much detergent goes into each grade is up to each supplier.

http://www.nealswheals.com/NealsVisi...tion_FINAL.pdf
Look at slide 30! In Shell's gas, 89 and 87 have two times the EPA standards. 93 has FIVE times the EPA standards.

http://www.standard.net/topics/busin...es-gas-quality
Going back to an independent study by Paragon Laboratories.

Want to know more? Keep Googling!

Posting things up here based on your own assumptions doesn't help anyone up here, unless you state that it is an ASSUMPTION. If you are not 100% sure you know what you are talking about, then say it is an ASSUMPTION or don't say it at all.

maxxxxspeed

K. So under YOUR thought. Diesel fuel (Octane of 15-30) has less energy then Gas (87-110)? Hmmm... Diesel fuel ACTUALLY contains about 150k BTU of energy where gasoline (100% Gasoline) only contains around 125k BTU and the usual 90% Gasoline + 10% Ethanol only contains 120k BTU
http://www.trucktrend.com/features/t...gas/index.html
http://www.uwsp.edu/CNR/wcee/keep/Mo...urcetables.htm

You bringing up the Ideal Gas Law proves my points below. and i will give you props up front before the ownage that is about to take place.

You are partially correct by saying "The increased pressure lowers the temperature at which the gasoline will vaporize/evaporate", but actually its not 'vaporizing' it is igniting. Hence the definition of ignition can be found here - http://dictionary.reference.com/browse/ignition and yes there are different definitions but in a chemical reaction its ignition as found here http://www.chemistrydaily.com/chemistry/Ignition_system

SO, yes the temperature need to activate decreases as the pressure increases because it higher pressure is adding MORE ENERGY going into the chemical reaction which in-turn decrease the energy required by heat to ignite the fuel.

PLUS.
Its called ACTIVATION ENERGY. http://www.britannica.com/EBchecked/...ivation-energy (Britannica is wrong though, and so is Purdue http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch22/activate.html#act


So for simple math for you.

200*F detonates fuel at 0bars
BUT
100*F detonates fuel at 100 bars

Notice how it is actually EQUAL energy (in this instance not really but to make it easy assume) It is MUCH MUCH MUCH more complicated than that but it works for this to prove a point.

EXAMPLE A DIESEL ENGINE (No spark plugs) it only ignites the fuel due to compression and diesel fuels octane is extremely low so it can be ignited by the cylinder pressure alone (fuel atomization and cylinder temperature comes into play as well...but doesn't apply to this convo)

Hence why in Forced induction and High Compression Ratios require higher octane fuel BECAUSE THE CYLINDER PRESSURE IS HIGHER, hence more energy is being added pressure) in excess of heat (spark)... It has NO effect on the power output. Higher octane fuels DO NOT contain more carbon per molecule than lower octane fuels. Its the same hydrocarbon fuel but higher octane fuels contain higher levels of iso-octane or heptane (anti-knocking agents or chemicals that increase the fuels activation energy). SO IN SHORT OCTANE RATINGS DO NOT STAND FOR FUELS ENERGY AVAILABILITY. It only stands for its tendency to ignite. You get the increased energy by the higher compression in the cylinder, NOT the fuel. Another, reason you are able to make more power on higher octane fuel to is to increase the timing so the fuel is compressed more before it ignites, hence once ignited, will output greater energy (per your ideal gas law). Which is why you need a fuel with a higher activation energy that will not ignite just from the compression and cylinder temps (knocking).

If you put 105 octane in a 4 banger with 8:1 compression your WILL NOT make more power then a 4 banger with 12:1 compression on 87 octane (although you may after awhile since you will probably ruin your pistons). Just trying to prove my point with extremes.

and water/met injection is added to cool the cylinder temperatures chemically, which allows them to up the timing and increase cylinder pressure either by High Comp heads, pistons, or forced induction.


SO TO BREAK IT DOWN FOR YOU:

1. Octane has NOTHING to do with how much energy a fuel has. 87 has the same amount of energy as 93. http://www.bajajusa.com/High%20Octane.htm

2. Octane ONLY refers to the fuels tendency to ignite in a controlled detonation. The higher the Octane the more energy it takes to ignite, therefore a greater amount of energy is released, not by the fuel but due to COMPRESSION (Cylinder heads and timing).

3. People opt for water/meth to keep their cylinder temperatures down so they can add timing and cylinder pressure without detonating. http://forums.nasioc.com/forums/showthread.php?t=937176

4. Diesel engines use a lower octane fuel so they do not have to use a spark to ignite the fuel. Fuel only combusts by compression and cylinder temps. and Diesels lower octane rating yet higher BTU COMPLETELY disregards your point that octane = the energy available in the fuel.

5. The reason you get 'more power' and 'better fuel economy' is because with the higher octane fuel your maxima senses it and in turn INCREASES the timing.

A couple more general sources.

http://www.hcs.harvard.edu/~jus/0303/kuo.pdf
http://www.biofuelshub.com/features/...abcs-of-octane
http://www.ftc.gov/bcp/edu/pubs/cons...tos/aut12.shtm
http://www.elmhurst.edu/~chm/vchembook/514gasoline.html
http://www.petrolprices.com/about-fuel.html
http://www.svfd.net/SVFD%20Files/Art...e_ratings.html



And on detergents... on your "independent study" of detergents... taken word for word COMPLETELY discredits YOUR ENTIRE ARGUMENT on the topic of detergents and how more are in higher octane fuels. Here:

"-- Among samples of regular unleaded gasoline (those with an octane rating of 87), Exxon had the highest level of additives (20.0 milligrams per 100 milliliters), closely followed by BP (17.2 mg) and Shell (16.2 mg). Trailing substantially were CITGO (6.0 mg) and Pilot (5.8mg).
-- Among premium fuels (92 or 93 octane), Shell took the top spot (31.0 mg), followed by BP (26.4 mg) and Exxon (21.2 mg). CITGO (9.4 mg) and Pilot 92 (8.8 mg) lagged behind the other three brands -- including the trio's regular gasoline samples."

HMMMM... Looks like some premiums have less detergents than regulars... In the future when you want to have an argument and you choose sources to back yourself up PLEASE read it, and do not just post what pertains to your argument.

Let me rephrase what I said in my previous post that you quoted to something easier to understand...

That SOME BRANDS ARE BETTER THAN OTHERS. Like in every other thing you can purchase on this planet. AND I NEVER DISREGARDED THAT. I WILL NOT BUY Kroger or Meijer brand fuels. Only Shell, BP, or Sunoco.

SO NEXT TIME CALL OUT SOMEONE WHO DOESN'T KNOW WHAT THEY ARE TALKING ABOUT... AND DON'T CALL SOMEONE OUT IF YOU DO NOT KNOW WHAT YOU ARE TALKING ABOUT!!!

So "DO SOME RESEARCH BEFORE YOU SPEAK supared"!

And I would say that was pure ownage....what about you?

G37guy01

Jeez, I would say depending on what in specific you are looking for there is truth in both posts.

1. The cruder diesel does release more energy than gas. My oil furnace releases more btus than an equivalent amount of gas.
2. However, to release that energy, it requires a commiserate amount of hardware.
3. I do agree the higher octane allows for more power by preventing premature detonation. In other words, the higher the octane the harder it is to detonate.
4. I also agree the name brands have better/more quality gas than no-name.

Thanks for the info.

Tommy K

'better fuel economy' is because with the higher octane fuel your maxima senses it and in turn INCREASES the timing'

I've noticed this dramatically since switching after 3rd tank. MPG noticeably better in the new ride.

My .02

Also, the simplest way I've ever explained octane is it's a fuel's reisitance to burn. Why it's used in hi-comp/boosted apps...won't preignight due to heat of compression...but in effect has the resistance to "wait" for the spark.

Later .ORG
Tommy K, owner
ZipSensors.com
World's Fastest Temp Sensors

T200

Really? You feel pretty confident knowing what I WANTED. That's amazing.

Seriously, though, if you've been following the posts, I was fine with 87 and didn't think there'd be much of a difference. But I do know that with 87, when I punched it, there was some hesitation and then it would take off. Not so with 93.

And even if it was simply running smoother as you say, I still FEEL it, whether I wanted to or not.

maxxxxspeed

Your right.

valhalla

I'll be running premium in mine only. The way I see it, if this is what the manual calls for in terms of it being preferred, then thats what I'm running. There is literally what, a $3 difference in cost for a tank of premium over regular? I don't know about you guys, but the difference between a $55 and a $58 tank of gas just doesn't impact me whatsoever...

QT1 5MT AE

iTrader: (6)

Regular : $3.79 x 20 gallons = $75.80
Premium : $3.99 x 20 gallons = $79.80

Fill up difference on a dry tank is a mere $4. you probably spend 5 times as much on coca cola weekly. I don't get how people lavishly spend money on junk food and sodas that are poision for your body but cheap out when it comes down to spending money on premium fuel which actually pays for itself in fuel savings and long run.

if you think about it, that 32oz coke you buy for $2.50 costs more than perimum per gallon, perhaps drink gasoline and fill up with cola ?

Ghozt

Great point. The same people probably buy a Starbucks every morning ($5), go out for lunch every day ($10-15), etc... just use Premium and skip Starbucks one day a week.

carnalc30

iTrader: (4)

you can see who runs 87 or 91 when the car comes into the dealership and its hooked up on the computer.

Your car may run ok on 87 but the retarded timing does show up if someone is looking for it.

I use 91 religiously, its recommended so I do, do I change my oil and not my filter to save $5? Why would I save a few dollars on something like gas when I could save it and not buy something stupid and unnecessary

max2k10

Premium on all my cars including my max. Like others have said, $3 more in my pocket a week won't break the bank or make me rich.

lightonthehill

Those posting about only $3 difference between a tank of regular and a tank of premium need to be aware that is a purely localized thing. Around where I live, the difference in price between regular and premium ranges from 30 cents to 48 cents per gallon, and reached 55 cents when we had that stretch where gas was $5 a gallon.

Even when the difference around here is at its minimum - 30 cents per gallon, that means the difference in the price of a fillup is between $5 and $6.

But I am not trying to justify using regular. That will never hapen in my Maxima.

Folks should, however, be aware that Nissan says they have this 7th gen Maxima set up for maximum performance at 91 octane, so running higher octane than 91 serves primarily to make us feel better about things.

Performance-wise, I will never believe anyone can tell the difference between running midgrade and running premium in this particular car without the aid of electronic timing devices. However almost any driver would immediately be able to detect a drop in performance using regular.

valhalla

Even if the difference were $10 a tank, and that mattered so much to anyone... they should be asking if they are driving the right car in the first place. IMHO of course.

lightonthehill

Exactly. Some folks here are using regular in their 7th gens, but if they are going to use regular, why not drive a Malibu or Fusion or something that the manufacturer intended to run on regular?

Nissan never intended that drivers use 87 octane in the 7th gen Maxima. Although a few here have found their 7th gen will run OK on regular, others found their 7th gen just did not run well at all on regular. That tells me that regular is very borderline as a functional fuel in the 7th gen, and not something I would ever put in my tank.

supared

Light. I had a full on Mechanical Engineering/Thermodynamics response to maxxspeed. Hit a key, and the page jumped to the top, and I lost my progress. It doesn't matter. If people care for the truth, they should go back to my original post that he combatted, and see that I said stay away from generic gas stations. Then, in his argument, he said generic gas was not high quality and only confirmed what I said. I spent my life fixing cars, then did 4 years in the Navy, and then graduated Magna Cumme Laude from the University of Florida with a B.S. in Mechanical Engineering and a Minor in Sales Engineering, in 2010. If he wants to get into a full on thermodynamics study, I could give him that - if we had the properties of each fuel grade supplied by each manufacturer. That is not going to happen. The thing that we can find in laboratories is the amount of detergents added.

This yields two results. For more detergents, YOU SHOULD TRUST BRAND NAME FUEL SUPPLIERS - not brand name grocers. Secondly, within the BRAND NAME FUEL SUPPLIERS, the gas is the same, as far as you can tell; BUT, the amount of engine preserving detergent in the gas INCREASES with GRADE. Regardless of what you are driving, it will last longer with higher grade, brand name fuel.

That was my original point, and no one could debate that!

supared

Look! I got money. If you cannot afford premium gas for the life of this car, then you cannot afford this car!

If I cannot afford $5.00 per gallon + my car payment + my other bills, on my salary, then I should not have bought this car. If you have enough money to cover this, and choose lower grade gas, that is your choice too!

I use premium! All day! Every day! --- my preference. What is yours? In your 2009-2012 Maxima?

maxxxxspeed

Supard... You say that detergents go up with grade so premium should have more than regular...

But in your link that was used to back up your argument you can clearly see that's not always the case.

And I also have a degree in mechanical engineering, am certified by 2 organizations, and earned a 3.625 all while playing Division 1 football.

O yeah I was also the president of the united states.

No one cares about who you are on the Internet. I could be a 12 year old kid and you could be a 47 year old guy who works at pizza hut... I don't know and neither do you. I have my opinion and so do you. I gave you my side, you gave me yours... Both are generally the same main points.

But if you want to continue the pissing match...

maxxxxspeed

Basically who gives a **** about gasoline... Use what the manufacturer recommends, if you don't, that's your choice... If your car runs fine on diesel then run it... If you think you need 105 go for it. Either way make a decision and either eat the cost of getting 93 or be satisfied with 3 less horsepower (at the crank) and a couple knocks here and there.


CAN WE PLEASE NEVER HAVE A DISCUSION ON FUEL AGAIN? ITS BEEN DISCUSSED 10000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000 000000000 TIMES! Do a search, it's all of the same info... Search google, buy a book, or form your own thoughts on it.

adl6009

Premium, at $4 a gallon whats another 20 cents a gallon?

lightonthehill

The price of gas varies widely. My local stations are currently priced at $3.69 for regular, $3.89 for midgrade and $4.09 for premium. That is 40 cents a gallon difference between regular and premium. That would be around $8 difference per tankfull. But I will NOT be putting regular in my Maxima at any price.

Supered is correct that the higher the grade of gas, the more detergents are added, so the cleaner the engine should be. He is correct that sticking to major name brands improves our chances of getting good gas. Even there, I try to avoid stations where it appears things are not being kept clean and well-maintained.

vr4z06gt

simple math really. Lets assume the DIFFERENCE in price, between regular and premium, is $0.20 (the usual, sometimes $0.25 or $0.30). Lets say you drive 15,000miles/year, and average 25MPG. You will need 600 gallons of fuel per year, with a DIFFERENCE in cost being 600*.2 or $120/year. The reality is that is not much, maybe a night out between dinner, drinks, and entertainment. Especially compared to the cost of these cars new, or used for that matter. If you are already so stretched in your finances that you can't come up with ~$120 per year to use the recommended fuel, you might want to consider buying a cheaper car.

And again this is the difference so it makes no matter what the cost per gallon is, be it $2 or $5, the difference between grades in non-rural areas is usually, not always, between $0.20-$0.30/gallon.

Boxer112

Ok this is strictly my opinion and my experience. Someone mentioned you get more power because the Ecu advances timing with fuel that is less likely to detonate. I agree with this. Seen on my. Subaru still that is more Moody than my pregnant wife. Now this is MY OPINION. you do get more power with premium along with better MPG. Now something I will try with my own car. I will put about 80% 87octane in my car and about 20% E85. E85 IS ABOUT 105OCTANE. The only problem with it is you need bigger injectors because it requires more fuel to operate. E85 in certain areas is cheaper than regular gas by about 25 Cents. So I ASSUME I will get the benfit of cheaper gas, better MPG due to timing advance and more power also. If you have any questions or better knowledge on the subject let me know. BE ADVISED, TOO MUCH E85 WILL PROBABLY CAUSE YOU TO RUN LEAN AND THROW A CEL.

maxxxxspeed

E85 runs at a lower BTU than regular gas... About 40,000 BTUs less. So with out bigger injectors your probably making LESS power using it in a non E85 equipped vehicle, and worse MPG...

Boxer112

Thats why i said i was going to put about 80% 87 and 20% E85

Boxer112

What i need to know which i cant seem to find is the Size of 7th Gen injectors.

maxxxxspeed

So whats that going to do? Dilute the 87 octane?...

so instead of getting the full ~120k BTUs from pure 87 you'll only get ~100k-105k BTUs from that mixture.... In return LESS POWER, WORSE MPG.

What your trying to do makes no sense without proper tuning and larger injectors.

Just trying to put some points out there for you to think about before you try this.

Boxer112

You are correct, proper tuning and injectors are required (still dont know the limitations of stock MAX' ECU and injector size). For example,I had an Sti with 950CC injectors. On pump fuel at WOT, my injectors were at 78% duty cycle. I would mix about 5 gallons of 91 Octane(was in California at the time) in my Subaru with E85. (13 gallon tank). The car's ECU always wants to run more Timing and my STI was a beast when I did do this because I had headroom from the injectors.
Not saying im going this route but The worse that can happen with The Max is the car throws a CEL from Running too lean( more fuel is needed with E85). This is why I was going to mix it with 87 Octane. 82/18. The best way to determine if the car is running correctly is if I had AFR gauge. All my ideas are from Trial and Error with Subaru's. I know this is a Nissan but it is worth a try.
The reason i thought about this is because i ran across an Octane mixing chart online.
Not really seeing how if i mix 87 Octane( which is what i use now) and 105, my results will give me worse MPG and power than what im getting now.
THIS IS ALL MY OPINION AND TRIAL ERROR. Not trying to say your wrong but trying to see things from a different point of view in regards to the Maxima because I honestly know Nothing about this car. Still trying to find out stock 2011 wheel weight. LOL

vcbcool

I Use 91 octane (have yet to find 93) and between switching to that and sythetic oil changes, i get more power and better gas mileage. I don't know which switch did what but the two together is worth the little bit of extra money.

anish3232

Used regular in my 2010 and got 20-21 mpg. Using premium in the 2011 and getting 24-25 mpg. On a full tank of gas that's roughly 60-75 miles more per tank, which is over 2 gallons of regular gas. Which is around $7 in the US. Premium will cost you less. 0.20 x 17 gallons = 3.40.

maxxxxspeed

Using regular 105 mixed with 87... You might as well run 93 (same price in the end). In the stock form (no tuning, no injectors) you will get worse mpg and less power if you mix e85 and regular 87. Power in an internal combustion engine is a function of the power potential of the fuel (BTUs)... Now if you upgrade your injectors and run new fuel lines (stock, regular gasoline compatable lines will not work with E85, you need special lines) and tune you will most likely get more power at the cost of mpg. E85 vehicles that run E85 get ~15-20% worse mpg than when they run regular gasoline. I know from experience as well from the mathematical point of view...

Boxer112

Two questions. How will it be the same price if i run E85/87 compared to 93 octane if E85 is cheaper than 87?
Whats wrong with Stock lines?You said I need "special lines". Regular gas uses 10% ethanol anyway so wouldnt Automakers make stock lines compatible with Ethanol?
With my Subaru and friends with Evo's running E85. Only things upgraded were injectors and pump and this is on Cars running over 400Whp. No sign of corrosion was shown on stock rubber lines for any car i have known running E85.
Now unless there is something different about Nissan, which i clearly stated my knowledge regarding this car is very low then i understand.

maxxxxspeed

I meant same price if you run 105 race fuel mixed with 87... Not E85. Probably running a 80-20 mix won't require new lines. If you run 100% E85 you WILL need different lines.