I could've sworn I read what type of gas thread in this...but I can't find it now. Today I just filled up on some "87 Press" gas for my 97 GXE. The other option was 93 Press but the price was like...over 40cents/gallon. So I decided not to take it (it wouldve been around 7-8$ more for a full tank). Is 87 press alright?

 

okay, before you get flamed. Read the manual, even the gas cap suggests: "PREMIUM FUEL"

The VQ is high-compression engine that likes higher octane gas. The minnimum octane rating is 89. The suggested rating is 91+. We have a knock sensor that "listens" for knocks when using a low-octane gas to trim the ignition timing to prevent knocking/pinging.

Now, that same sensor is known for going bad after about 80K miles. If it's bad, IT WILL NOT set off a check engine light, but throw a ghost code. In this case, the ECU is always in safe mode (so it doesn't matter what octane you're running".

THREAD CLOSED....

 

^ right except the minimum octane that can be used in a 4th gen is 87 ;-)

This is a very debatable topic. I do believe that this whole "For maximum performance use premium" slogan is a bit of an exaggeration. Think about it, Lexus and Toyota share the same V6, but Lexus tells users to put in premium while Toyota is run on 87, because the target market is different. How many people would buy a Camry if it ONLY ran on 91 ?

Plus the name of the car "Maxima" and "...For maximum performance..." I duno to me it sounds a little sketchy, why would Nissan design an engine that can be slowed down and ran on lower octane than optimal? so it could not be timed properly and eventually fail ?

Just throwing out my 2 cents ...

 

he's kinda right.....87 is just when u think its time for the car to die and stop costing you..

 

from what i have read, 87 is fine if your knock sensor is in good shape. some .orgers will say there is a drop off in performance and some milage when the engine is working in "safe mode".

 

IBTL

When I first bought my car, I didn't pay attn. to the manual, threw a KS code, changed it and realized once I got it out that it was perfectly fine and realized that it was from running 87 fuel. I don't know what the previous owner filled up with buy since May, 93 is all my car has and will see. I have paid almost $3.50 p/g too.

But seriously, this topic has been covered to death and it will be locked soon.

 

Well, manual says 89 AKI, gas cap says premium. Maybe even NI$$AN is confused. Everyone has even tried 87 and said that performance sucked, or they went thru it faster. I say it's your car, put in it whatever you want. If you want your car running in "safe mode", it's your car.

The car is made to handle any unleaded gas in case you ever have to gas up somewhere in Uzbekistan with 50% 85 octane/ 50% goat ****

My car only sees Shell V-power (93). The extra 30 cents/gallon don't bother me.

 

When the KS senses knock, ECM backs of timing and enrich fuel mixture. Then gas mileage suffers. So a 10% gas mileage degradation running 87 could actually cost the same as running 91.

This was noted by that OZ guy looking at the ECM binary code.

Since gas is different everywhere, I would try a few tanks of both then decide what is best for your car.

 

..oh and andrei, please compare the two:

http://www.edmunds.com/used/1999/toy...441/specs.html

http://www.edmunds.com/used/1999/lex...254/specs.html

I wonder if the extra 16 horsies on that same engine would be the reason why the same engine would require higher octane?

 

You got it, maybe thats the difference in performance lost due to using lower octane

I dont think the difference is that extreme on the VQ30DE (certainly not 16 horses) otherwise it would be a lot more noticeable.

But also pay attention to the curb weight and mpg estimates, the lexus weighs only 100 pounds more and the mpg is lower by 1 and 2 mpg respectively (city/hwy).

So does that mean better performance at the cost of MPG ? cause i really dont think the 100 pounds makes that huge of a difference. What about those who say their mathematics prove that different octanes produce the same MPG, i dunno, kinda have to wonder...

Good find man!!! (oh and i dont think any maxes were imported to Uzbekistan, maybe Tadjikistan hehe)

 

Lol, you are a riot bro!

I think that the difference in weight would most likely negate the performance "increase" (not to mention the MPGs), but more like if it was 200 pounds

It also seems to me that since they upped the peak HP to 5800rpm. Then in order to even "feel" the difference between the two in an identical car, could feel it up there in the rpm range.

Anywhoo, we're getting abit off-topic. I leave you all with a reminder about a little tidbit in the FAQs, where someone dynoed some engine with a dead KS vs a functioning one with 91 octane. There were ~20HP losses. I know i definetly felt a good difference after having my KS replaced. (But i always do 93 oct).

 

It is in the General Maxima Forums.

 

Since you guys brought this topic up, how do I check my ECU is not running in safe mode. I just got my car and god knows what the previous owner was running on it. So now how do I check and finally would it really matter what gas you pump in the car overall ?. New Maxima owner!

 

Roshansri, welcome to the forums, and congrants on the maxima. I'm sorry, but we get at least one of such threads every week. Please read the FAQs and HOW-TOs in this section. You will find the answers to that and more! I've spent a week reading through all that when i came on board, and it was well worth it!

 

http://forums.maxima.org/showthread.php?t=546100

 

have your local parts store or dealership run the codes. though the KS will not trip the Check Engine Light (CEL), it will still come up as a code. if that code appears, you will need to replace the knock sensor. that is how you tell if it is running in safe mode.

and, for an extra 3 dollars per tank, it doesnt bother me that i might be gettin "tricked" into buying the more expensive stuff. it makes me sleep better at night.

 

I've used 87 before. Only cuz I wasn't paying attention

All I noticed was that I didn't get the performance that I usually get with 91.

 

higher octane will not have anything to do with performance, other than fooling your knock sensor into retarded timing.

ive asked around for a while and never really get a straight answer about octane. i drove volvos and a 1993 maxima on the cheapest gas i could buy for 6 years with NO PROBLEMS. no knocking, mpg was fine, etc. then i get a 96 and 97 GLE and find out that not only do you all obsess about high octane, but it also says in the owners manual to use high grade gas......ive tried both since and see no difference in MPG or performance. i still use high octane (and thats only cuz i put a new KS in) but ive been asking around.


my uncle actually used to work with aeronautical combustion engineers at an airport in the 70s. apparently when he was my age he was also right in the middle of the high octane vs. low octane argument.
he did a fair amount of research into it over the years and ended up talking to one of his longtime friends, a "fuel prodigy", who said that high octane, 91, would yield no cleaner or better results than low octane, 87, in the engine of an automobile. only in high performance engines such as that of a race car or airplane - where rate of burn is highly sensitive - would you see a difference.

the way he explained it was this. when the valve fills up with the air/gas mixture and ignites, it will burn much smoother with higher octane gas. the composition of the gas is designed for the explosion to be consistant in combustion - meaning it will burn at a constant and static rate from one end to the other. this, as it is, may result in SLIGHTLY reduced horsepower, because the piston is not firing as violently.

lower octane gas does the opposite. it ignites rapidly and progressively, which causes the occasional engine knock. this engine "knock" is the very reason people use 91 in the first place. lower octane gas, especially in engines as simplistic as ours, will actually yeild no damaging effects as far as the knocking goes because our cars are designed to deaden this knock (the piston hitting the valve ?). it does happen occasionally, but not enough to warrant putting an extra 4 bux into your tank everytime you fill...

i used to think the octane levels had to do with impurities in the fuel, probably from those shell commericals with the tiger jumping out of the hood, but i was wrong. they are both filtered and cleaned equally as well due to the restrictions of US energy commissions.

basically, he calls me an idiot for filling my car with high octane

im still putting 91 or 93 in my maxima but its something i do think about when pressing that big yellow button at the gas station