jixxxer

Do you put the premium fuel in the max>? My wife has just told me she has been puttin the 87 octane fuel! Does it really make that big of difference??? What octane is premium??

bk2k3max

Actually you should never put anything below 91 Octane into your Max, my ex-wife put 87 into my 03 Maxima and I'm telling you now that thing ran like it had the hiccups.

It took at least 2 days of driving it down to empty plus several bottles of Octane Booster in order for it to start running half way decent, once I got the tank down to 1/4 I filled it up with 93 (what I always use or something higher/94 if I can find it) and she ran like new.

Don't let your wife put anything less than 91 into your tank, Nissan tells you that our engine is designed to run its' best on Premium.

There are many write-ups on this on google as to what are some of the things that may happen to your car as a result of running with less than Premium fuel.

NCSUpilot

Owner's manual is very specific on what fuel to use. I say the designers know best what to use. I always have and will stick with premium.

bizarjuggalo

I use 87 in mine most of the time and haven't had any problems. Gas mileage has been the same and no knocking or hiccups. 93 is recommended but so is ester oil.

maximusprime

+1

Mick7

Estimated HP loss 15-20 due to timing retarded for regular. Which mean MPG loss also which pretty much pays for the premium it is supposed to have.

NCSUpilot

On my old '95 I consistently got 25-25.5 MPG on premium. One one tank, I used regular and it reduced to high 23. Obviously there are a lot of variables but for the most part my driving style and conditions remained pretty constant. If you work that out, like Mick7 said, the premium pays for itself in MPG.

bk2k3max

Well, according to this article you guys might just be right 100%:

http://www.usatoday.com/money/autos/...emiumgas_x.htm

bk2k3max

One more for good measure, looks like I might start using Regular, unless I decide to go and race my car at the track:

http://www.edmunds.com/advice/fuelec...3/article.html

lightonthehill

Nissan always recommends premium fuel with the Maxima, but all previous generations ran well on any octane. I always start out with premium for a year or so, then drop to midgrade for a year or so, then run regular until the next generation arrived. I have found no obvious difference in the car's performance between any of the three grades, but have no doubt a controlled elapsed time run might have measured a difference.

I also measured the exact same miles-per-gallon with all three grades with each one of my Maximas. That surprised me a little, although I had long known that scientists say octane is not technically directly connected to MPG.

This ability to use regular was a very good thing for me last summer, when my local stations reached an unimaginable FORTY-EIGHT cents difference between a gallon of regular and a gallon of premium.

BUT

We are talking here about the 7th generation, which has a HIGHER COMPRESSION RATIO than previous Maximas. Nissan has changed the 'recommendation' of premium to stating that premium fuel is THE fuel to be used. In fact, they state that, if regular has to be used in an emergency, put only enough in the tank to get you to where premium fuel is available, and do not do any vigorous acellerating or high-speed driving until you have premium in the tank.

Although I would not be bothered by any small reduction in performance that regular fuel might cause, I feel performance may not be the only downside to using regular in this engine, and would strongly suggest regular fuel not be used in the '09 Maxima except in a true emergency. This engine is designed for 91 octane, so why not use 91 octane (or 93, if ****).

bk2k3max

The more I look, the more I find:

http://www.consumerreports.org/cro/c...-904/overview/

http://www.sciam.com/article.cfm?id=...tion-premium-g <<<Great Article here, a must read.

Last one:

http://www.consumerenergycenter.org/...s_premium.html

I'm sold, I guess you can consider me a "New Convert" to Regular Gas at the Pump from now on, unless I'm going to the track.

lightonthehill

I have pushed those type articles for years, knowing most vehicles do fine with regular fuel.

BUT

I would suggest you be careful not to read these referenced articles too superficially. Maximas through the 6th generation (and most 'premium only' cars) could be said to fall into that large pool of vehicles where premium is recommended, but regular works fine.

By contrast, this '09 Maxima engine ACTUALLY DID move up to a genuinely high compression ratio, which means the onboard computer has a more pronounced adjustment to make in order for this engine to run on regular, and with regular fuel, this engine will not be operating as designed.

As one who has eventually used regular fuel in all my Maximas of the past 25 years, I would still feel the '09 Maxima may be the first one where the use of regular could be detrimental to the engine and fuel system.

anomaly117

iTrader: (3)

87 works fine. but 93 will give you better throttle response and all around performance. its recommended by the manufacturer and they know best

choice89

I wrote in a different post about the differences in my gas mileage when I took a road trip from MO to TX. I can only use 91 octane here in Missouri because that's all they have and I average around 23.5 MPG all the time. I then took my trip and in Dallas I used 93 octane and averaged 27.5 MPG!!!! I can't wait to leave this cold winter jail and get back to Warm sunny San Antonio!!! I will be there in 3 months!!!! 93 Octane here I come!

dkmura

The other thing to consider is the longterm effects of detonation when using regular unleaded. Have you ever taken a close look at the crown of a piston when subjected to continued detonation? When doing teardowns of high compression (12:1 to 14:1) Nissan road racing engines, the hot spots formed will actually pit the surface of high-dome, forged pistons.

While the Maxima VQ35DE's 11:1 compression isn't a race engine, those of you continuing to use regular unleaded are missing out on three fronts: engine performance and economy will drop as Light and others have stated. But the damage to the coated aluminum pistons in your VQ may be the biggest factor to consider. I wouldn't want to imagine the uneven combustion (and ensuing hot spots) caused by the use of less than 91 octane fuel in this engine. You've spent your hard earned money on a great car; why abuse it by saving a few pennies on gas?!

BlueMax

Reading those articles carefully as Light suggests, it seem they mostly address using premium fuel in cars recommending regular, or cars recommending, rather than requiring premium. Although the owner’s manual does not say “required”, the wording “Use unleaded premium gasoline with an octane rating of at LEAST 91” and the sticker at the filler saying “premium fuel ONLY” convinces me to spend the little extra.

Our mileage (mixed city/highway) has been creeping up from about 18 on the first tank to just over 24 on the last tank with 3,100 miles. The driving has been mostly the same except I have to punch it once in a while now that it has enough miles. But I also spend more time being amazed at how I can keep up with traffic with the tach below 2000. Your mileage may vary.

And to dkmura's point, since I can't see inside the engine but hope to keep the car for several years, better safe than sorry.

Asav

iTrader: (1)

True. I don't claim to be an expert on gas, but I do know I get much better gas mileage using premium as opposed to regular. That's all I need to know.

made in china

iTrader: (7)

My 3.5 gets much better MPG on premium also, about 2-3 MPG better, which actually makes premium CHEAPER to use in my car ('04 VQ35 with '04 ECU).

The gas door on my car still says "Premium recommended for best performance" for the old VQ30. The VQ30 didn't care if I used 87, 89 or 91. It always got the same MPG's.

Not so sure what the long term effects are of running lower grade fuel in this newest 3.5 would be, but why chance it? It seems everyone else who owns a 3.5 is in agreement that at least the MPG's with 91+ is so much better than 87, that alone should make it a no-brainer. And since the 09's have gone from recommending to requiring premium, I don't get why you'd insist on putting 87 in your brand new car

a33i30

iTrader: (4)

Why does'nt California have 93? Anyways you could use low grade but its not worth messing with the engine for a dollar or two.

Maxgal

I certainly won't drop off using the 93 octane as it is recommended for this car. I'm finally able to drive this car as I normally would as break-in period is over.

This car really has some get up and go on the highway and I can easily pass people, though it gets blown all over the road in the wind.

I'll stick to 93 octane as I don't want to risk any damage to the cars engine. Prices have been dropping and like others, if they rise, I'll just drive less rather than risk that damage.

lightonthehill

I feel you are very wise to stick to premium with this car. One detail - The '09 Maxima engine and fuel system were designed for 91 octane, which is premium, and as high as octane gets in many states. 91 is the octane Nissan recommends for this car. The 93 may make us feel better, and there will be urban rumors telling us it gets better MPG. There may be situations where 93 octane bests mid-grade (89) and regular (87) in MPG, but I feel any MPG improvement of 93 octane over 91 octane would be under half of 1 MPG, if that.

But, details aside, premium is definitely best for this '09 Maxima.

drakutis

She's my baby and she's getting premium!

mynameispee

iTrader: (3)

higher compression ratio motors are more prone to detonation. octane rating is also referred to as anti-knock index (AKI) which is the fuel's ability to resist premature ignition.
higher octane = higher AKI

Maxgal

Most gas stations around me only carry 93, so I think I'm stuck with it where I live.

lightonthehill

Same where I live. In fact, I only see 91 when I am in other states such as NC. I don't think I have ever seen a pump with four grades, so it makes sense that all stations in a particular area would carry the same octane as their 'premium.'

I'm just glad that the insanity of last summer, where the difference between regular and premium reached 48 cents a gallon at the stations in my area, is over. At that difference, opting for premium was indeed sacrificial.

Maxgal

Agreed. I won't change grades no matter what. I paid a lot for this car, and I'm not going to ruin its engine. I also love this car and that's another reason.

rays01se

93 octane for me. Upon delivery, the dealer filled it up with 87 octane. When that tank was empty, I filled it up with 93 octane and I noticed the difference right away. where I get gas my only choice is 87 or 93.

mls277

93 is the way to go. Especially with gas prices back to normal its actually not that expensive.

lightonthehill

91/93 (whichever one is available in your area) is the way to go for sure. But you can delete the 'not that expensive' bit, as that depends on where you are.

My local stations are charging 20 cents a gallon more for midgrade and 40 cents a gallon more for premium. On an 18 gallon refill, the difference between $1.99 a gallon and $2.39 a gallon is noticable (around $7.20 added to the $35.82 regular would cost, making $43,02). I feel my stations are not playing things 'straight up'.

NCSUpilot

As an FYI, almost everywhere in NC it is 20 cents more for premium over regular.

maxfever1987

iTrader: (93)

y cheap out when its only 1.50-3.00 more per fill up, instead of spending hundreds or even thousands down the road for another engine, the VQ is designed for 93-premium, be good to it and it will be nice back to you.

ManojK

logistically it doesn't make sense if you look it....say for example you average 15000 miles a year and get about 25 mpg. You would need about 600 gallons of gas. Where I am at price of reg. is about 2.06 and prem. is about 2.27. You are only talking about 10% bump in the cost of a fillup. Is saving 120 dollars/year worth the cost of replacing the engine down the road? I wouldn't sacrifice it. I would notice the sluggishness of the engine when I accidently put regular gas in my 02 maxima. Why would I put it in my 09?


Manoj

lightonthehill

Yes, by all means, use premium in this '09. But your cost difference is not correct for some areas. Iit costs me over $7 more per fillup for premium. But I still pay that extra money and use premium.

One more detail: This great '09 engine was NOT designed for 93 octane; it was designed for 91 octane. But that is not important. because there will normally be only ONE of those two octanes (91 or 93) available in any given area, and this engine loves either one.

lightonthehill

The situation varies by individual vehicle. I used premium the first year in both my '00 SE and my '04 SL, midgrade the second year in each, and regular the last few years in each, and, as far as I could tell, there was not any noticable difference in performance between octanes with either of these cars. I measured the MPG regularly, and it certainly never changed.

Having said that, the compression ratio in this '09 engine has been bumped up to where using regular gas would be a very poor decision, and would put this engine in an operating situation is was never intended to handle. Performance would suffer, and the engine would not be operating efficiently. I will never be using regular in this baby.

Topend

Without recording mileage between regular and premium,just watching gas gauge tells me the savings are undeniable (in town),let's not forget the potential damage to the engine as a whole.My 06 murano has the same appetite for any octane with no change in overall performance

omelet1978

I'm thinking of getting a used 09 Max. I really don't want to put premium fuel in if I don't have too b/c I drive ALOT...I've heard the argument where it says "you are buying a 30k vehicle so what is a few extra dollars at the pump", but here in Vegas it's about 30 cents more expensive than regular. I drove an 08 Altima on regular with the same VQ engine and it ran just fine on regular.

So bottom line, will I make up the money buy putting in premium fuel?

MaxLoverAz

iTrader: (1)

So you can't afford $6.00? You probably should look at another Altima or a Versa/Sentra/Cube. To each his own but the owners manuals doesn't state that Regular is an option it's only to be used when Premium isn't available.

omelet1978

Well the reason I'm asking is b/c I'm driving upwards of around 30k miles a year. I currently have a 2005 Acura TL and it requires premium BUT it gets b/w 24-25 mpg which is significantly better than what fueleconomy.gov says.

The Maxima I found is used, so that helps with the high mileage thing, plus in Vegas if it is private party you don't have to pay sales tax which also helps ALOT.

If it is at all realistic to get 24-25mpg it would make me feel better about using premium. If not then I don't think it will be the deciding factor in getting a new Maxima...

lightonthehill

omelet - I began with premium, then worked down to midgrade, then regular in all my previous Maximas, and continued to get the same MPG and almost the same performance. BUT, the compression ratio has been bumped on this '09, and the 'premium recommended' has changed to 'use premium fuel.' Period.

The '09 can be run on regular in an emergency, but with no aggressive driving, no high RPMs, and premium fuel added to the tank ASAP. With regular, this fuel system will have to make adjustments that will mean the engine will not be operating at full efficiency.

ALL stations around me are charging twenty cents more per gallon for midgrade, and FORTY CENTS A GALLON MORE FOR PREMIUM. But as bad as it may hurt your wallet, I would URGE you to avoid using regular in this '09 Maxima.

If it comes as any consolation, several posters here have been getting 30 to 32 MPH on open freeway trips. For a 3600 pound car with 290 HP, that is very good efficiency.

Deucekegler

Hasn't anyone noticed the decal on the gas cap/fuel door which says "PREMIUM UNLEADED FUEL ONLY" ???

it's not like NISSAN has partnered with the oil giants and wants you to spend more on gas. The vehicle is simply designed for premium.

Here in new york, the price between 87 (reg) and 91 (premium) differs as much as $0.70 in summer months. Ofcourse it hurts the wallet...

But I wouldn't feed a Tiger catfood. nuff said