I just read a thread from 2009 where everyone was saying "Oh no, no regular gas in this new 2009! It's got a much higher compression motor and you'll damage it in the long run! It's my baby, premium only!" Well, the tech is 10 years old on these cars now and while they are still nice cars...is anyone actually still using premium? It is quite a bit more money for a tank of premium right now and my owner's manual says "Recommended but not required." It's probably $8-10 more per tank for premium. The thread I was reading had so many people saying they notice a huge increase in MPG using 91+ octane but I just read several articles saying cars were tested and achieved the exact same performance and fuel economy using regular and premium...so we don't need it. I've been running 87 octane in my '13 and she purrs like a kitten. Anyone else?

 

I run 93 all the time.. get 24 mpg in town....

 

 

Yea my old fogie 09 with 80k still drinks 91 because the compression is still there. No need to go shopping for crackers and jello. BTW 91 only costs me $3 extra per tank.

 

2012 with 80.5k miles on it. Getting 23 mpg on 91 octane and sometimes I treat her to Shell brand V-Power(not even sure if that's higher than 91 or just extra shell additives). No intention on using a lower grade. It's only like +/- 20 cents difference anyway. Call me bougie but I'm not letting 87 grade touch this car lol

 

I purchased my '99 brand new and I have never and I will never use anything but premium (93 octane) ...

 

I have a 2010 and use premium when it's cheap enough but I mainly use regular and have had no problems at all, A Nissan tech that is a friend of mine said it's recommended but isn't a requirement. These cars run fine on regular and performance loss is minimal if any. A car that is Premium fuel required must run on premium at all times but our Maximas are not required it's strictly a recommendation to help boost acceleration, Using lower octane such as regular you may notice a little slower acceleration in cars for which premium fuel is recommended. It will not damage your car, Now if it was turbo charged and required Premium fuel you would notice the performance loss instantly and hear pinging etc. Save your money go regular and from time to time when premium is cheap enough feed it some but otherwise you will do just fine with regular.

 

Premium still with 110K on the odo.

 

The owners manual of my 09 and the label on the gas cap door specifically states to use only gasoline with octane rating at least 91. It also goes on to say that if premium is not available the use of 87 octane can be used for short periods and to avoid full throttle driving and abrupt acceleration, and to refill the tank with at least 91 octane as soon as possible.

 

Instead of looking at others' empirically trial and error results of using lower grade fuel, you guys should do more research on why different octane fuel is recommended on different motors in the first place. If it were in the 90's to 2005 era, associated issues would be higher when you down grade your fuel, but since modern engines most often times come with more complicated ECU's to control variable valve timing and ignition timing, you'll see less of a problem nowadays. The main enemy on using downgraded fuel than the recommended octane is "knock". And back in the distributor ignition timing days (with no variable valve timing), knock occurence is more likely when using downgraded fuels. Knock is the real enemy against prolonging the engine life as it puts impact on the rotating assembly inside the engine.

On our VQ engines, we have a very good ECU program to control both ignition timing and valve timing to quickly react to knock. Therefore, you're okay to downgrade your fuel and still get away with major engine component problems, even in the long run. Additionally, this VQ motor by design has its sweet spot to burn octane 91-93, so if your octane level isn't too far below that, you won't lose much performance. It's when you use something like octane 87 which will likely cause much pre-detonation, then the knock sensor will pick up these readings and ECU will respond by retarding ignition timing and/or hold intake valve timing longer to bleed off some air and get a lower compression ratio to match what the downgraded fuel will require to burn without that pre-detonation. With the controls making this adjustment, you'll lose some performance as the engine isn't running as efficient as it could.

Bottom line is, the engine on this Maxima and the technology it comes with, you can pump any grade fuel into it, it'll all work because the sensors and the computer is smart enough to figure out the best way to burn that fuel (to an extent, of course, unless the motor has a variable compression upgrade like some of the new infiniti's. However, with different grade fuel, the output power level will differ for sure. There's no two way around it. As far as reliability is concerned, it won't mythically hurt the engine as bad as it would compared to the old generation motors. Remember, our VQ motor started its debut on the 1995 Maxima when all it's got was advanced timing control, no variable valve timing or much of anything else. and it was already a very good motor back then. As each generation of maxima come out, the same motor gets fit with upgrades and safety changes which evolved to what it is today.

 

Well said, You explained that perfectly it will not harm the engine but will lose some performance such as the boost in acceleration and won't run as efficient but it won't do harm either.

 

Everyone can make up their own minds.. Me, I listed to what the engineers who developed the engine. After 406,000 miles on my 09 SV, I still only use 91 or better. I am not saying I wouldn't have made it this far without it, only that I don't second guess they guys that made the engine, wrote the software for the ECM, and put it all together.

 

holy crrap, you have 406k miles on your 09? Thats incredible! How much maintenance has been required to reach that? These cars are beasts if you treat them right. Im at 126k on my 09 and have only put premium in it since day 1. Just did my CVT oil and change the filters yearly. Oil changes every 3-3.5k miles. Only issues I've had are the hub bearing of course, and now they are telling me my control arm in the front has a lot of play in it

 

~15 gallons @ $.30 difference in price between premium and regular unleaded is only $4.50 per fill up. Pretty much chump-change for most, so...why not go with the fuel that will give you the most performance?
I drive my Max hard and it loves the premium fuel. But as Godfather so well said it...the engine will perform fine on regular unleaded. I know a lot of people running 'mid-grade' and feel it is the best...but to each his own.

 

I own a 10 Maxima SV with 217k on it. I started using premium, then mid grade, then regular to which i have noticed no difference in MPG or performance. That's a good thing because i fill up about 2.5 times a week which in the long run saves me a lot of money. But to each is own, if it makes you happy, go for it.

 

Maybe there's some difference in the 5.5th Gen electronics but I've ran 91 octane in my car and the small but noticeable detonation (rattling) was present. So I've run 93 for most of the life of this car which is a 2003 SE with 210K miles on it. If your compression decreases then using a lower octane is less noticeable. High octane guards against detonation on high compression engines... that easily detonates 87 octane or 91 octane due too their lack of anti-detonation qualities. Remember extremely high compression ratios can detonate fuel like a diesel if you're using lower octane gasoline!

 

 

Remember, the 09 model was the only one with the label "Premium Required" all the other 7th Gens are Premium "Recommended"