Read in the book that the car wants 96 octane. Where I come from (Canada) highest is 94. Why does Nissan demand more octane, when other manufacturers--Honda, Toyota--don't ask for this high? I drive a GLE, so it's not exactly sport-tuned.

MaXXX

 

You must be referring to RON 96, which is the same as 91 AKI. 94 AKI fuel is overkill. From the 1997 owner's manual, page 10-7:

Recommended fuel:
Unleaded premium gasoline with an octane rating of at least 91 AKI (Anti-Knock Index) number (Research octane number 96).

If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 87 AKI (Research octane number 91) can be used.

However, for maximum vehicle performance, the use of unleaded premium gasoline is recommended.

You can safely use a lower octane gasoline without hurting your engine since your Maxima has digital knock control; that is, the ECU retards timing to prevent pre-ignition/detonation/pinging if the use of a lower-than-recommended octane gasoline causes such a phenomenon.

As for why the VQ runs best on 91 octane fuel, I cannot answer that because I dunno.

 

91 octane fuel allows for maximum compression before ignition, permitting use of the 10:1 compression ratio of the engine. Using 87 octane, the ECU will ignite the fuel mixture a little sooner before 10:1 compression if knocking is detected. There is no evidence that the engine can advance the timing beyond that yielded by 91 octane, so I would say that anymore more is overkill. And you are right, 87 will not harm the engine.

 

I found this post very useful, because I have a 2000 Maxima SE, automatic, and I've used regular(87), plus(89)and premium (93) at different times. I'm glad to read that use of regular gas won't harm the engine. I get the feeling that the mfr. recommends premium to get the maximum performanc they advertise?

Anyway, one question I have is: is there any difference in gas mileage between regular and premium? Thanks.

grandpa

 

I am wondering this as well...

I have a 2002 and the salesman filled up with 87, so I am babying it until I am out of gas. I have managed to pass a few people, with no knock.

So far I have put about 100 miles on it this weekend driving around town and am getting an impressive 24mpg on 87. I should get even better with 93 right?

 

the owners manual told me to use 91 so i use 93 because thats the next best thing..

the owners manual also told me to drive with my head lights on during the night, wear my seat belt, put oil in the car, change my spark plugs.. but just because i have seen my unlce drive 15k miles without changing his oil and he likes to clean off his spark plugs.. i am going to do it too

 

 

 

You will not harm the engine using 87, but you will get slightly better power and gas mileage on premium. But remember than premium usually costs 10% more than regular. I would be hesitant to believe that it will yield 10% better gas mileage as well...that would over 2MPG extra! Highly unlikely.

If you cannot feel the difference in power between regular and super (most people can't), then you aren't doing anything wrong by using regular. But using 93 isn't a bad idea either. It depends what you are willing to spend.

 

http://www.off-road.com/rick/gas2/

http://www.off-road.com/rick/gas-tech_part1.html


Happy reading...

 

Interesting post, but it doesn't address the role of the ECU and knock sensor in compensating for lower octane gas.

 

cool we got a grandpa on here