Well, my gf was driving my car for few days, and after that my car just felt very powerful. Acceleration was smooth, and it ran just great... I found out that she used 87 gasoline. after that i tried 91 ... and it seemed to be sluggish. I switched to 87 again... and my car is super-fast... How is that possible?
isn't it suppose to run better on 90+?

 

i had the opposite happen. My car was running kind of rough after 3 months of regular and it runs great immediately with a tank of premium

 

.....................

 

that's what i would say... but reality is different... i have this car since 03, and always used 91+ ... and now i see a huge difference , i don't know why it is like that, that's why im asking.

 

No proof, no care ....
#1) all you have is your as.s. dyno.
#2) It wouldn't be worth it to get a real dyno anyway.
#3) It's probably something else affecting its performance or placebo, or just a waste of a thread being taht it's a minimal gain if that

Or a call out for :attention:

 

Umm... I'm talking out of my *** since I'm no expert on fuel, but it would seem that there are only a few situations where 87 would run better than 93 in your Max.

87 will combust more readily at lower compression levels than 91 or 93. Maybe your Max is suffering from compression loss. It's also possible that your timing is somehow messed up.

 

thanks for an answer... it seems like it gained a lot of power on high rpms. I will def look into that...

NmexMAX: I'm sorry I even asked the question..

 

And Answers to Other Gasoline Questions

 

You are talking about a maxima right? Have you seen the label on the gas door saying, "premium" recommended for maximum performance?" Show us a dyno proving that 87 octane is better than 91 octane on a maxima.

As spiromax said, the only way 87 would run better is if you had some serious problem like leaky rings/valves thus lowering compression.

Or maybe it felt faster because you hadn't driven it in a few days and then you got a $hitty batch of 91 gas.

 

Wow, NmexMAx, must be having a bad day. Atleast be somewhat respectful!

 

2003 Maxima:

 

Don't worry about NmexMax, he's always like that....

 

i assume that dyno shows the difference between premium over regular? 13 hp/tq is pretty significant for just a difference in gasoline grade. that's a better gain than almost any single mod except for headers. wow!

 

This is because the timing is retarded and more fuel is squirted in order to run a richer mixture, providing less power and worse gas mileage.

 

Yep. You have to realize that there is a reason why our manual says to run premium only. To achieve the 222/255 crank HP on our cars, you have to run premium. But it's not just that, it's also better for keeping the engine clean, and preventing unwanted pinging and knocking issues. Seriously, edmunds doesn't even know what the f*ck they're talking about 99% of the time. The 10-cent difference between regular and premium won't make or break you.

 

This is truie at times. ...

There is also a similar discussion w/dynos in the 4th gen stickys .... My point being, this would pertain to the 5g DEK.

 

It's only 15-20 cents more a gallon which works out to be around $100 more per year to operate asuuming 15K miles per year. Is giving your maxima that gas she needs worth $9/month or 30 cents per day? LOL, I sound like those Christian Childrens Fund charity commercials now....

Since you prolly have a 5th gen, you prolly paid 10k-25k to purchase the car and are fretting over 15-20 cents per gallon?

 

I know that when I tried to run 87 octane, my car would knock and ping like hell and as soon as I put in some premium fuel, it stopped.

 

Source of dyno. It was an Altima 3.5, not a Maxima. My bad. Same engine, so whatever. http://forums.maxima.org/showthread....ht=octane+dyno

 

From my understanding, even though the altima has the same engine, it would still have different numbers at the wheels than a VQ35 powered maxima.

 

Why is that?

Only thing I can think of is the transmission, but from that dyno and stock Maxima #'s, it's right on par with a 6M Maxima. ...

 

Hm, good point... Perhaps ECU is different?

 

First you have to prove that they put down different #'s, then we decide why ... i.e ECU .. Until then ...

On altimas.net, there are may autos in the high 230-240 and a couple in the 250's, but they use STD, and also their times don't show anything better than our fastest autos.

 

That's exactly why they call anything else than a dyno a 'butt dyno' -and here is proof positive that butt dynos fail us....

 

Yeah ... butt dynos stink

 

Nobody gave you an answer. How about this for a guess? Your girlfriend used different brand of gas.

- Vikas

 

If you read the original post, you would realize your answer is completely ridiculous. Genius

 

What were you driving while she had the car? Was it something with considerably less power? It might just be that it feels faster, even with lower quality fuel. I can definitely tell a difference between 89 and 93 fuels.

 

adid u go to the same gas stop u always go to? maybe u went somewhere and got bad gas?

 

I was advised by the stealership svc guy, the 3.5 has a pretty high compression and requires 91+ for better performance. My brothere did me a favor and filled up on 87 one day. When I got the car back, it drove like crap. I could definetly "feel" the difference after filling up with 93, or was it all in my head?

You may have some other issues if 87 octane "feels" faster.