high888

The owners manual recommends 92 octane, however it also says you can use 87 octane. I understand that there must be a "knock sensor"
which would retard the timing to prevent predetonation should it happen, because of the 87 octane rating. I have been splitting the
difference and using 89 octane with no problems. What am I missing?
92 octane is well over $2 per gallon. It ain't cheap.

CanadianMoFo

Use whichever you want to. It doesn't make a difference in operation.

I use 94 in the summer (though not at the prices they're charging now) for slightly better fuel economy. I use 87 in the winter since my fuel economy is in the toilet anyways with the cold weather.

CM.

jc53

Last time gas prices got "out of hand", I'd fill the tank with 92; then when half-empty, top off with 87. Then run the tank down to one quarter, fill with 92, then repeat. Seemed to work fine for me. But that was a much older Max.

MaxMaybe

I used 92 octane for the first 1,000 miles and switched to 87 after that.

I can't say about better performance with the higher octane fuel because I was taking it easy breaking the powertrain in. All I can say is that this vehicle runs VERY STRONG with 87 octane.

However, when the temps increase as we approach summer, I will be listening for any knocking from the engine. If I do notice any, I'll experiment with higher octane fuels.

bluemaxx

I farted around trying to figure this out last summer. I used only Shell 87 or Shell 93, three tanks of each. Kept records and all... If there is a mileage difference your going to need a scientific calculator to prove it on my car. I didn't do dyno testing but the sphincter says no difference in performance either. Most guys around here will tell you premium fuel only but a lot of them will also tell you that your 04 won't crack a 15 flat quarter.

I almost always buy 93 though. Kind of the same reason I use Mobil 1. I just like doing nice things for my car.

SteVTEC

You'll never hear any. That's what the knock sensor is for. It'll pickup the onset of knock long before your ears ever hear a thing and the ignition timing will get retarded, with the side effect of lower power and efficiency.


You can run whatever fuel you want in these cars. If you have a very granny driving style you could probably get by just fine on 87. But the engine was designed to run on premium, and you'll get the best overall performance on premium. If you have a more aggressive driving style then run the engine on what it was designed to be run on. Premium. If you're driving hard on 87 octane the engine will always be at the onset of knock, timing will get retarded, and your overall performance and mileage will go down to the point where you might as well have just run premium anyways.

high888

So, in order to get the most power, the timing is advanced, which then
requires the 92 octane to prevent knock. However, those clever
Japanese designers built in an idiot feature which is the knock sensor, so
if you use 87, the timing is retarded so you don't screw up your engine.
Ah so, very interesting.

bluemaxx

I wonder what kind of gas that guy was pouring into his loaner car to clock a 14.279? If the dealership put gas in it you can bet your *** it wasn't premium.

SteVTEC

I've seen dealers put in either.

bluemaxx

I'm not saying it couldn't happen but car dealers are some of the cheapest bastards known to man. It's hard to believe they would send the porter to Citgo to gas up the loaners with premium. Maybe the guy that took the loaner to the track put premium in it.
I'd pay $200.00 for a Celine Dion ticket before I'd put premium in a loaner, but that's just me.

lightonthehill

The '04 seems to run great on mid-level (89 octane). With my style of driving, that should be fine. 87 would work, but I feel I am 'meeting the car half-way' by using 89.

I put only 93 octane in my '00 Maxima for two years, then switched to 89 for the next two, and was unable to detect any dropoff in performance or MPG. But then I am not a very aggressive driver.

I did read somewhere within the last year that the worst thing one can do is switch between 93 and 87 frequently. The sensors evidently reprogram gradually, and don't switch between extremes very fast. To 'blend' the two (93 and 87) by switching while the tank is still a third or half full should be fine.

If gas prices get much worse, almost everyone will be using 87 octane.

MaxMaybe

Here's an article from "AutoSpies" that addresses the issue, albeit from a "reverse" perspective:

http://www2.autospies.com/article/in...9&categoryId=1

Tvetti

Let us do a simple math.

Say 92 Octane is 0.30 more than 87. For a tank it saves $6. Assuming Two tanks/month saves $12 ie approx $150-$180/year. Should we have to take a risk of damaging 30k car just to save some couple of hunderds over a year?

bluemaxx

No risk of damage that I'm aware of. Risk of diminshed performance maybe but it's going to be hard to prove.

andymax95

Since I've got a job, I can afford the 93 octane gas. but when the parents we supporting my a*s,( with 4 4th gen max's) I only could use the 87 octane, cause I had to spend money on other stuff that burns, but my cars ran fine, I do notice with the higher octane, I spend more cash on something pointless, I still get the same gas milage and power from the engine, I just use 93 octane as a precaution, cause my foot loves to mash the pedal all the time. Just my 2 cents

jackconly

We've got our '04 down in Mexico where 87 IS high test, and have had no problems whatsover. Been here for 6 months!

Mike_TX

Boy, that brings back memories! I took a new '67 GTO (back in 1967, you see) down South of the border. Before I could even get aimed back toward the USA, my car started backfiring through the 4-bbl carb (that was what we had before fuel injection, kids) and running like stink. I managed - barely - to limp back to civilization, where I was told I had 8 burned valves, among them several intakes (hence the fire through the carb). I finally unplugged a couple of spark plug wires on the worst cylinders so I could continue to limp home to Dallas.

That terrific Mexican gas cost me half my vacation and a valve and top-end job.

Me? You won't catch me skimping on no steenking octane!

Mike

bluemaxx

It sounds like your goat was starvin for lead.

Edify11

I've always put in super unleaded in my 97 Maxima and I'll continue to do so in my 2004. One question... where's everyone getting higher octane gas? 92 used to be standard here but now everythings 91. Is 93 and 94 available here (socal)?

gmc74

I haven't noticed any performance issues with 87, and I have been running it since I got it almost a year ago.... except a few weeks were I tested 92 octane to see if the mileage or performance was better. I didn't notice anything on the performance side, and the mileage was the same. And it definitely gets hot here in AZ.

SteVTEC

It might take more than a tank to adjust. On the 03+ Accord V6's (the engine is "technically" designed for premium, but they derated it to only 240hp/212tq on regular for marketing reasons), the shop manual says that if there is any knocking the engine will keep the timing more retarded for 300 miles. So if you run 87 and the engine is at the detonation limit and running in retarded mode, it'll take a tank or so of 91/93 gas to get it back up in the performance mode.

As for that autospies article, yeah, that's generally true. But there are always going to be exceptions.

Allenz

"There is no gain. You're wasting money," insists Jim Blenkarn, in charge of powertrains at Nissan in the USA.

jrussell915

I used 87 Octane in my '93 Max with no issue for the life of the car. When I bought my '00 Max, I noticed knocking upon acceleration when using 87 Octane. The dealer checked the car out pretty thoroughly and suggested that I try filling the car with 91 octane or better. That solved the issue, and since the owner's manual stated to use 91 or better, I could not argue with the dealer.

I have not tried 87 octane it in my '04 max yet, but may do that just as a test. If it proves ok, I may stick with it to mitigate some of the high fuel costs. I fill up 2 - 3 times per week because I travel a lot.