Prophecy99

iTrader: (1)

thanks...for the explaination...i figured most of the above...
for now I will stick with 87

isaacbush

only premium pump

lightonthehill

I'm happy for those who feel the premium gas babys their car. With 87 octane costing $2.91, midgrade costing $3.09 and premium costing $3.25 (the three stations nearest me), that is a difference of 34 cents per gallon, which is $5.74 more per 17 gallon tankful for ZERO improvement in mpg. But if it makes a person happy . . after all, the Maxima is a car worth babying.

maximized98

iTrader: (16)

Use only Shell 93. Do not know why, since most of the gas comes from the same storage tanks. The only difference is that different brands put their "touch" to it by adding their own additives. So i guess its just an old habit why I use shell. No different than chevron or exxon

lightonthehill

maximized98 --Sometimes the reason we do things is fairly convoluted. I began using Shell gas back in the 1950s when they changed to Gousha maps, which were more accurate, detailed and easy to read than were the Rand-McNally, General Drafting, AAA, Hammond or the maps of any of the dozen or so lesser cartographic entities.

That was important to me, as I have collected maps since WWII. I have a complete set of maps of all western states distributed free to customers by gas stations between 1934 and 1938. Of what interest are these antiques? In looking at a 1935 map of Nevada, I see a large area marked as the 'Clark County Game Ranch' northwest of Las Vegas. But for the past half century, we have known that area as 'Frenchman's Flats Atomic Testing Area'. Time changes things, but perusing these maps can bring back the past. At my age, the past is important. I visited the Clark County Game Ranch in the late 1940s.

bigjoe87865

iTrader: (1)

Im happy to say... that im satisfied with my switch from 93 to 87... already ran 3 tank fulls.... and iv been making the same ballpark miles per tank numbers with 87... there was none of the "93 is worth it because u get about 30miles extra to the tank"

and my car still feels fine to me.... not slower or anything.... no knocking or pinging... no CEL lights....

hell... i doubt it has anything to do with the octane.... but MY CEL would give me EVAP codes alot... and i would just ignore and clear the code while i was running 93

but i cleared it one last time... and have been running 87 for 3 tanks... and no lights yet.


=)

lightonthehill

bigjoe - Congrats on a successful octane change. When gas was a buck or so a gallon, and the price difference between 87 and 93 was between 10 and 20 cents per gallon, giving our babies 'the best' was understandable, even though it did not improve the mpg.

But with premium well over three bucks a gallon, and costing 34 cents more per gallon than 87 where I live, using premium and getting no more mpg seems less practical.

Pearl93VE

iTrader: (14)

I do not use premium to "baby" my car. It is actually required with a knock sensor bypass and advanced ignition timing. My mom used 93 Octane in her Buick Century and she recently switched to 87 and has actually gotten more miles to the gallon with the regular. Given her engine is not performance oriented at all; some cars just don't call for it. But when you have the chance of messing something up if you don't use premium gas, you bet your bottom dollar I'll be putting the extra $5 in at my next fillup.

bigjoe87865

iTrader: (1)

and if your car isnt having premature ignition... wouldnt the 5$ go to waste?


well... aslong as in my car i dont hear any knocking and pinging.... nor do i see a downfall in MPG which could indicate the KS has retarded the timing.... i will continue 87

lightonthehill

bigjoe - You are correct. If 94maxshima's car is in proper tune, the 87 octane will have no negative effect whatsoever. Except on his wallet.

He evidently did not read through this thread, where it is unquestionably established that Nissan is very clear that Maximas are designed to run perfectly well on 87 octane. There have been high compression engines built that did not have any computerization in the fuel system, and did require high octane fuel. I have owned several, such as my 1966 Old Delta 88.

But the Maxima's fuel system is computerized, and adjusts to the octane it finds is present.
The only time a higher octane makes a difference is if the Maxima is not in proper tune, or if it is going to be used in an extreme situation, such as a timed quarter mile.

But I'm sure big oil companies love to sell the more expensive grades of fuel.

bigjoe87865

iTrader: (1)

yup.... it took me like 4 tries of reading through the responses in this thread to grasp the concept...



btw... when you say.. it would matter in extreme situation like a timed quarter mile...... what does that mean exactly?..... what will happen if i do a 1/4 race on 87?...

Pearl93VE

iTrader: (14)

Right, under a proper tune, and untouched engine I would agree with you. But look here:

So if I do in fact have my knock sensor bypassed with a resistor, wouldn't it only make sense to run premium gas to insure it does not knock?

bigjoe87865

iTrader: (1)

I guess you have a point... but like others have said... the engine doesnt knock in a properly tuned engine in NORMAL DRIVING conditions.... so even if you didnt have 93... it wouldnt knock..... unless you were in an extreme environment and or racing...

i dont know much about what you did with the KS... and resistors and what not... wanna explain that stuff to me?... i wanna learn.

kvg

premium always other wise less power and mileage so cheap gas costs more in the end. at my high altitude it knocks and i notice a huge diff

lightonthehill

kvg - You didn't read the thread. You do NOT get less 'mileage' with 87 octane. The cheap gas does NOT cost more in the end. And the power difference is NOT quantifiable in normal driving. If your car knocks, it is not in proper tune. Of course, depending on the situation, it may be cheaper to just use premium than to get the car fixed.

94maxshima - I'm no expert on the 94 Maxima, but, although I have driven my wife's trucks, I have owned no vehicle but Maximas for over 23 years, and have friends who also drive Maximas (Our nearest dealership is a large Nissan dealer). Most of those friends use only regular gas. Only a few young ones use premium. I have never heard a single one of those friends who encountered any knocking. I have driven one of my Maximas as much as 206,000 miles, and whenever I detected a hint of a knock (only happened twice), a quick tuneup made it disappear. For me, it is as simple as this: The Maxima Owner's Manual would not tell us regular gas is fine for the car if it wasn't.

bigjoe - I would be surprised if a quarter mile run with the same Maxima using 93 octane and 87 octane gave more than a tenth or so second difference. Of course, in competitive situations, that tenth of a second difference can be huge, AND IS THE PRIMARY REASON NISSAN RECOMMENDS PREMIUM GAS; the car mags tests will show the Maxima a tenth second faster, and that is a big deal to auto fans. Nissan knows this. But in normal driving, that tenth of a second is totally meaningless.

LvR

I am afraid if you are trying to attribute a motor's knocking to hight above sea-level, you are sadly mistaken.

The higher you go, the less dense the air is and thus the less the absolute pressure experienced in the power stroke of the motor - ie its less prone to knock the higher you go given the same fuel.

Pearl93VE

iTrader: (14)

My car doesn't knock. The VE30DE engine had a poorly made knock sensor in which they would crack and fail over varying amounts of time. This meaning that without a proper signal running to the ECU, it would retard the ignition timing by instinct, running any grade of gas while having a BROKEN knock sensor is fine, the car is smart enough to realize this and retard timing meaning it takes precautionary measures to insure it doesn't knock.

HOWEVER, with the knock sensor harness disconnected, and a resistor bridging the harness creating a bypass for the knock sensor all together. If the engine WERE to knock, there would be nothing there to compensate for it. Which is WHY premium gas (providing a longer time to be burned before detonation) is a smart thing to choose while having the knock sensor bypassed.

I have it bypassed only for performance reasons, and as of this far I haven't had any problems with it running premium gas. It's not so much that it is an expensive part, but I would love to find another reason to go under my intake manifold for as well, then just replace the knock sensor while I'm down there.

lightonthehill

94maxshima - I understand. In your special situation, the 93 is definitely safer. And the 93 may keep some engine parts a tad cleaner, although I have seen this argued several ways.

01_blue_max

93 octane for me and 8 oz. of marvel's mystery oil

foodmanry

iTrader: (15)

Leaded diesel combo...it's my secret, shhhhh.

MaxEx

I just filled up my 04 SE with 89 after it had been using 91. I noticed a small amount of pinging at first with low rpm, but it soon went away. I'll let you know on the mpg's.

foodmanry

iTrader: (15)

I actually switched over from 91 down to 87 a few weeks ago. I've been running 91 in my 2k max since I bought it new. First thing I noticed when I switched down to 87 was BETTER gas mileage. I got about a 2 to 3 MPG increase over the 91. So...I'm sticking with 87.

No pinging for me...of course my engine has never pinged.

lightonthehill

The pinging at first when switching down in octane will sometimes happen, because the owner's manual says it takes about a full tank of gas for the computer to completely adjust to a different octane.

MaxEx

That makes sense. After I wrote that I noticed a small amount more. It doesn't happen at low rpm, only when I step it down about halfway. It will ping from about 2800 to 3500 rpm.

z00york145

I've used 100 octane ONCE. It was 6$ a gallon and i didn't notice much of a difference. On the pump it said "for track use only" but I used it on the road.

As for normal I would fill up with 91-93 octane, but with gas prices now I'm thinking of going to 83-89 now.

ScottS

iTrader: (2)

Here is some more reading. Credit to NAJ on www.turbododge.com Source: Chrysler

NO: 14-08-97
SUBJECT: Poor Driveability With High DI (Driveability Index) Fuel
DATE: Nov. 21, 1997
SYMPTOM/CONDITION:
Long cold start times, warm-up sags, hesitations, and driveway die outs. These symptoms are most noticeable and severe at moderate ambient temperatures between 4 - 27 degrees C (40 - 80 degrees F).

DISCUSSION:
Gasoline with a high Driveability Index (DI) can cause the above described symptoms. DI is a measure of the gasolines total volatility, or tendency to vaporize completely. A high DI number is less volatile than a low DI number. Most premium gasoline sold in the U.S. has a higher (worse) DI index than regular or mid-grade gasoline. Use of premium gasoline is NOT recommended for vehicles designed to run on 87 (R+M)/2 regular or 89 (R+M)/2 mid-grade gasoline. High DI gasolines also cause higher emissions for the same reasons they cause driveability problems.

For vehicles that require an octane rating of 91 (R+M)/2, premium is recommended, or possibly required. Using premium fuel with a higher than recommended octane rating is not recommended. Owners who experience fuel related cold start and warm up driveability problems should try a gasoline with the recommended octane rating or different brands of gasoline until they find one that provides good performance.

The octane quality of gasoline is only a measure of its resistance to spark knock. The use of higher than recommended octane gasoline under normal operating conditions does NOT improve startability, idle quality, fuel economy, driveability, acceleration, engine durability, or emissions. In fact, most higher octane gasolines available in the U.S. have higher DI values than regular gasoline. Customers are most likely to experience poor driveability with premium gasoline than with regular.

Some vehicles, such as Viper, Prowler, 5.9L Grand Cherokee, 2.0L Turbo Talon, and 2.0L DOHC Neon have been specifically designed to take advantage of higher octane. These vehicles may have higher compression ratios, and/or more aggressive spark calibrations which provide optimum performance with the specified higher octane. However, other vehicles which are not specifically designed and calibrated to take advantage of higher octane will not benefit from higher octane.

Some vehicles may experience light spark knock in situations such as trailer towing or climbing steep sustained grades. Light knock or 'ping' under these conditions is not harmful. However, if the customer is concerned about light knock under these circumstances, the use of 89 (R+M)/2 or even 91 (R+M)/2 premium gasoline may be temporarily warranted. If a vehicle is experiencing heavy spark knock on gasoline with its designed octane rating, this may be an indication of excessive combustion chamber deposits, or some other problem. Combustion chamber deposits can be removed with Mopar Combustion Chamber Conditioner p/n 04318001. Standard diagnostic procedures may help in identifying other potential causes of excessive knock.

Some gasoline marketers may advertise that their premium gasoline contains extra detergent additives. Under provisions of the Clean Air Act, ALL gasoline sold in the U.S. must contain effective deposit control additives. Nevertheless, if fuel injector or intake valve deposits are suspected of contributing to poor performance, occasional use of Mopar Fuel Injector Clean Up p/n 04549613 is a much less expensive way to maintain engine cleanliness than regular use of premium gasoline.

The attached charts (Figure 1 & Figure 2) show the negative effects of high DI fuel as related to customer satisfaction.

If fuel quality is suspected in causing a customers driveability concern, your zone technical office may be able to provide direction on procedures for fuel sample analysis.

POLICY: Information Only

minsbang

I've recently switched from 91 to 87 on my '04 max with 129k miles. I don't notice any difference and wonder why I didn't switch 2 years ago. I get about the same MPG (depending on how I drive) and get to keep that extra few $$$.

ltpacct

I have been using 87 octane gas in my '97 max for at least two years. I couldn't tell whether it runs better or worse than the higher octane gas I used when gas price was much lower.

hfxcastillo

I have a 2000 Maxi and I only use 93. Brand, I only stay loyal to Chevron, as far as I know, its the best quality gas here in California, Los Angeles

bluejays026

i have a 98 and i use unleaded but sometime i go to premium if i am draging.

20V6

I'm using 55% 95 RON (90-91 "yankee" octanes) and 45% E85.
E85 has 104 RON octane, so with this mix I get 99 RON octane which would be equivalent to approx. 94 "yankee" octane. My car has the knock sensor bypassed with a 470k ohm resistor.
Consumption is higher due to the high alcohol content, however due to E85s lower price, the cost per mile is the same.

MaxEx

Alright, I've used different octane gas in the last 3 tanks and have noticed no difference whatsoever. The ping is not a ping but possibly some kind of whine from the transmission or belts. I haven't figured that out yet. The shell 93 didn't get rid of it. I just put in BP 87 and it runs the exact same. I'm sticking with BP 87 until I can find a reason to switch.

lightonthehill

Smart move, MaxEx. For years many posters here have spouted the same old 'its worth it to feed my baby the best, and it only costs a nickle more a gallon' hogwash.

So many folks don't seem to understand the Maxima is designed to run JUST FINE on any of the three standard octanes, with the only restriction being that it takes about fifteen gallons of 'run-time' for the onboard system to fully adjust from one octane to another, so frequent octane switching will keep the car from running efficiently.

As to the 'nickle a gallon difference' myth, my local stations are currently charging $3.05, $3.21 and $3.37 for 87,89 and 93 octanes; 'nickle' my eye.

kzoosho

iTrader: (16)

100 sonoco 93 shell 50/50 mix

L8rMr

I always use premium;burns slower.

max98se5sp

87 shell

Qbridg3

My gasoline always supreme.

Only premium just because I don't mind or care,

MaximaN00b

87 octane, Always mobile gas stations..
I have used higher octanes, like 93 at highest i think from a sunoco, noticed no difference.
I've owned my max since April of 07, put about 12k miles on it by now too, and havent had ONE problem.. well it has scared me and sputtered alil here and there when I used gas other than Mobil. So maybe there is truth to the VE liking higher octanes. But its to expensive and its JUST a maxima, so 87 mobil gas works fine for me, and my car seems to enjoy it

MazerMadness

I use mobil/sunoco 93 in buffalo, thats the highest you usually see here.
I heard that a delta sonic in niagara falls sells 100 octane, but I never seen that myself.

#1berettaman91gtz

I use 87 octane cauce I'm cheap.