I just got my 2002 6MT SE Sterling Mist Maxima today. I have one question & sorry if it has been asked before: If I use 91 octane gas will I get improved performance compared to 87 or 89 octane?

 

Short answer: NO.
Higher octane only reduces the liklihood of knocking or pinging or more properly, detonation, which is bad for the engine. The ECM (engine control module) can compensate for some knock, but the 3.5L V6 has a tendancy to knock even with 91+ octane under moderate load at 1700-2000 rpm.

 

Performance, that's hard to measure. it's always recommended to use 91 octane per manufacturer spec. However if you use lower octane, it'll run but you'll gonna notice decrease of performance where the knock sensor has to compenstate the injector to inject more fuel to counteract the compression of the octane.

 

There has been a dyno a while back that actually showed that he got better hp with 93 octane compared to 87. We dont have 91 around here just 87, 89 and 93.

 

Here is MY understanding of the way it works:
87 octane is more likely to cause knocking than 89 which is more likely than 91 or 93.
When the ECU detects knocking, it retards the timing to attempt to compensate. The retarded timing will reduce engine performace. That is why it says on you gas tank door to use premium for maximum performance.

 

????????????????????????
j/k, but please explain "compression of the octane."

 

I doubt there will be any noticeable performance gains with 91, although you'd definitely reduce the risk of pinging... like others have already said. Btw, just curious to know where in DC 91 is available... never seen it sold at any gas stations around here....

 

i notice my car to be sluggish on 89 yet preppy on 93.... on take off only that is.

 

Preppy? wearing a collard shirt or somthing.. i agree tho the car is more Peppy, or willing to rev to redline

 

smarta$$...

I get noticably better mileage w/ premium.

 

octane does not compress...the only thing that compresses is the air. fuel itself does not.

 

I get better milage and performance w/ premium. I did a compairison a while back (don't have numbers anymore) and found that it was slighlty cheaper to get the premium because of the better milage. Of course, with changing gas prices, it could vary, but I would think that it would be a wash or very close to it in the end. Stick w/ premium: you don't want to lose to a ricer when he revs his engine next to you!

 

Thank you all for the replies. Very helpful. Also sorry for the confusion, I meant 93 octane NOT 91 octane.

 

91 i think is available mostly in the northwest... While i was on a road trip the gas grades went down as i went up north and more into the mountains.. i guess due to the altitude.. anyways regular was 85.5octane plus was 87 and supreme was 89 (this was in Billings, Montana).. some stations had 87 89 91...

 

I have a 2k and using anything other than premium gas is a no no. I bought my car used with 21k miles on it and the pinging I bought it with never went away. Finally I took it to Nissan and told them not to give it back until it was fixed. After 3 weeks of changing random parts and replacing the whole air induction system the car was fixed. The previous owner used regular gas and it really messed it up. I don't suggest it. It you don't want to spend the extra money to buy the best gas get a toyota. Nissan's to my experience are high maintenance.

 

I have to agree with that, one time my wifey put 87 in my 2k Max and that thing ran like crap, it struggled to put out any power when I pressed the accelerator.
I asked her if she used the right gas and she was trying to hurry up and put the wrong gas in, boy did she ever.

It took a couple of bottles of octane booster and some serious driving to get my car to act right, so bottom line is: Follow the owner's manual and instructions on what gas to use, it is there for a reason.

 

Preppy.... man I haven't laughed like that for a long time. I know it was a typo but it was funny.

 

question I have a 01 max and I know that the owner previous put 89 and when i bought the car they told me 89 because gas was chaper, but what i realized was once i put a fuel cleaner, and 91 my car was getting much and i mean much better mileage. Can any one tell me if i put 93 will the Max go even better on the mile?? Or same sh*t just keep it at 91? I mean for 2 or 3 cents more I dont mind puting the 93 over the 91 if it really makes a big difference? But I will agree with everyone on that 89 is a big difference then 91 on performace, and mileage