The way i see it is if i dont eat out once or twice a month i can put that money towards using 91 instead of 87.

The car stays happy and that in turn makes me happy.

 

Also, just a heads up for you guys who don't 'notice' any difference, this likely points to either A) you not paying enough attention to your car or its mileage, or B) you have a bad knock sensor or other component, which is causing the car to go into 'safe mode' for timing and retard the timing regardless of the fuel used. This is why you notice no difference, fix your problem, try it and post back.

 

False. It's recommend in some models but not required in all of them.

 

I've noticed a difference in mileage when filling 91 octane from different pumps.

 

Can't answer why maximas do not require premium, but for my 04 G35x Sedan, as per owner's manual, it states... coupes require premium unleaded (Octane 91 or higher)... G35 Sedan -- Premium unleaded recommended -- but regular unleaded (87 Octane) acceptable.

 

Not sure where you're getting this from, but Maxima's certainly do require premium.

 

Sorry, meant to say I don't know what Maxima's require for gasoline... I only know that my G35x sedan owners manual say a sedan can use either regular or premium unleaded but premium unleaded is recommended... G35 coupes require premium unleaded.

 

I don't know what it is about gasoline threads that brings out so much misinformation.

91 vs 93 is irrelevant because it is all 'Premium'. It varies by state depending on altitude and environmental regulations.

Premium fuel is NOT required in all G35's. I know this because the fuel door on my G35X specifically says 'Premium fuel RECOMMENDED for maximum performance'. In other words it won't hurt a thing if you use Regular, but it is tuned for maximum output running on Premium.

The fact that the car has a VQ doesn't really have anything to do with it. This is proven by the fact that not even all G35's require Premium fuel and they are all VQ's.

Mid-grade and Regular are not the same. Mid-grade is a blend of Regular and Premium and is required to have a minimum octane rating of 89 depending on location.

Compression ratio is directly related to the required octane rating. The higher the compression, the higher the octane required. This is not to say there aren't other factors.

Many countries use the Research Octane Number (RON) or the Motor Octane Number (MON) to measure octane levels. The United States uses the Anti-knock Index (AKI) which is an average of the two (R+M/2).

In summary, just because you drive a G35 does not mean you are REQUIRED to use Premium. Look at your owner's manual or fuel door and base your decision off of that.

 

Wow. So much good info mixed with confusing/incorrect/misinformed info.

The best part is that your post starts out saying precisely that, just before you contradict yourself in the same post...

You say this, then you say this:

I'm confused, is the Octane rating regulated or not? I can't imagine it's ok in one context for them to say the same fuel is 91 as 93 just cause it's a different state.....but you say the mid-grade is regulated to 89 octane. So is ther regulation on these numbers or isn't there? The fuels octane rating doesn't change at different altitudes, but the required octane the CAR NEEDS changes at different altitudes due to different atmospheric presure, etc.


You know this cause it says it on your gas door? Your "interpretation" of what that sticker "means in other words" is not a determining factor.
Almost EVERY Nissan has that exact sticker on the gas door, the gas door is not where you determine what gas you use, just as the Sidewall of the tire is not where you findout what pressure to put in your tires. Both make sense as places to reference, but both are incorrect.
Every single G35's owners manual says 91 Octane. If your G35 is magically different from every other one, then please post the paragraph in your owners manual that says so.

True, but most VQ's require 89 or 91. Certainly not exclusively, so consult owners manual.

More "misinformation" as you put it

Though it's true that very high compression engines tend to use higher octane, the VQ's and specifically the VQ35DE are far from high compression engines. There are a shytpile of engines running higher compression that use Regular gas. The Compression ratio is not the primary reason for higher octane needed, though it IS a factor, it's far from the primary one

Sounds like you sir might want to take this advice in yourself. I already posted the paragraph out of the G's owners manual.

 

(comin from a jew) Don't be a Jew! Your driving a luxury car. Whitch means preuimium expenes and premium parts also mean you need to use preuimium gas. My GF has a 2k maxima. We put 93 in it just like my G. We haven't had a single engine problem with the max EVER. Dirty cheap gas can cause your internal engine parts to go bad faster. Don't be a Jew!!!!! Lol just put the preuimium in unless you want car problems down the road . I know you don't so put the right gas type in your car

 

It's hard personally in Canada, where the price difference between a regular fill up and a premium fill up is normally over $10 to a tank. Personally, I still do it as much as possible. I'm not going to lie, there's times that despite all my posts here verifying that premium is what you should use and all the reasons why, I've been known to cheap out every once in a while on my maxima.

The G will never, ever get that treatment though. And on the maxima, it's even dumb because the cheaper gas yields worse mileage so in the end I'm probably losing money or breaking even anyways.

In the states though, it makes no sense to run anything else because the difference in price is so minimal there.



Also, I hadn't bothered to say this because in the G it's alittle different, but people are wasting there money for the most part getting higher octane gas. ie. putting 94 in the car instead of 91 is a stretch. Higher octane won't yield better performance in most models unless you've modified something (advanced timing, etc)

On the Rev-up models, higher octane gas than the recommended 91 may create benefits, I'm not sure, the Mapping on those engines is more complex and they might acutally be able to do something with the better fuel. But on the standard VQ models found in the 03/04, and the VQ in the Maxima, it's a waste of money putting higher than 91 in on a regular basis.

The only benefit in those applications is if you're using ethanol free-gas. Check here to find out who has it in your area: http://pure-gas.org/
However, most stations that have ethanol free have it in the 91 octane range, you rarely have to get higher octane ratings to acheive "no ethanol"
vShell V-Power ranges from 91 to 93 octane both with and without added ethanol, but always check the pump, as some stations still add ethanol. If they DO, it MUST be labled over a certain percent (IIRC, around 5%)

I'd also recommend you all Google "Top Tier" and go to their web site and find out what fuels in your area are on the top teir list, and use them.

 

I don't even know where to begin with this. You clearly don't know what you're talking about at all on the subject. Pretty much everything you said is wrong.

It is a fact that octane ratings change by state. The requirements for regular and premium change depending on altitude so gasoline retailers change what they sell accordingly. That is why premium is 91 in one state and 93 in another or regular is 85 in some states and 87 in others. As long as you are using the grade level required for your engine in whatever state you happen to be in you will be fine. As far as mid-grade goes, go back and read what I wrote. Since it is a blend of regular and premium it will obviously vary by state in direct correlation to what octane levels regular and premium are in those states. I don't see how any of that information contradicts itself.

The (R+M)/2 for each grade level is regulated. In other words, if they say they are selling a certain octane level for a certain grade, the gasoline in the tank is required to be at least that level of octane. It is also a fact that different countries around the world measure octane using different standards. The United States happens to use an average of the two most common measurements (RON and MON).

I stated that compression ratio is not the only determining factor in octane requirements. It is directly related though.

Your quote about not believing what your gas door says is pure gold. Also, my manual specifically says Sedans with 5AT's are required to use 87 AKI gasoline while 91 AKI can be used for improved performance. I'm not sure how much clearer it needs to be.

If I can't trust what my car specifically says to use what can I trust? I can say for certain it won't be anything you say.

 

VQ designed for a gas that burns with flames.

it's really hard to find.

 

Haha +1

 

my users manual clearly says, to use at least 87 but 91 is recommended. i hear that may have changed for later models but i can't confirm. although i'm sure you'll be fine running 87 in any G due to the fact that that's what dealerships put in their loaners. my ECU was re-tuned for 91, so that's what i use. on my Wife's G, she puts in whatever, normally 89 though. when i put gas in it, i choose 91 because i'm used to paying for it, so it doesn't bother me.