My wifes aunt has an 01 and says ever since they got the car new they have been using regular gas and only using premium on every 5th fill........

She says she have never gotten a SES or felt anything different.........
...
is this bad for the engine?? ??

Thanks,
Mike

 

If it pings and damages the engine she is screwed. In higher altitudes (Denver) or when premium is not available you can use less than 92 octane but it is not recommended for continued use since the engine was designed with premium fuel in mind. If it doesnt ping that there should be no problem. She isnt saving much money by using el-chepo gas. Hope she will notice if it starts to ping.

 

Regular can't hurt the engine. I'm on my 3rd Max and have never used Premium. I've have yet to have engine problems. The only thing that is noticed is performance. If premium is such a benefit then why doesn't the Altima 3.5SE with the same engine as the max NOT require premium? Stick with regular and pocket the difference, desperado regular is currently 1.57 a gallon and 1.87 a gallon for premium, thats almost $5.00 a fill up x 2 fill ups per week, that is a lot of money $40.00 more a month on gas alone is a huge difference. I will say this though, if she does do the regular route, stick with the good brands such as BP, Mobil, Shell, etc. Chris

 

Besides The Pinging She Will End Up With Alot More Build Up On The Internals And Most Likely The Car Will Have Detonation, Not Failing To Mention The Computer Will Be Like Wtf Is This Crap And Have To Readjust And Not Run Right.

 

Lower octane is more prone to ping under hard load. Either way the knock sensor will pull timing if it sense engine knock. It's not a big deal. 10.0:1 compression isn't really THAT high.

TK

 

Thanks for the help..........truth is I never even though about getting regular......(plus the wife likes following the rules..so if its says required then thats what we get).

Will using lower grade gas lower mpg? I remember on the TL board people saying in the end it all evens out since though you pay less for regular you get less miles per gallon so you end up filling up more to get the miles.......
so in the end you don't save much...

truth is..alot of this does not make sense..the accord v6 with 240 takes regular...yet the the acura (tls recommend 99-03) want premium..its wacked.
Thanks again,
Mike

 

I can't speak for the cost vs. mpg part of the equation, but you may experience lower MPG with regular gas, especially if it pings a lot.
I remember trying 89-octane gas in mine once, and the mpg was around 2mpg lower than "average", but that may not necessarily mean anything... sometimes I get 2mpg lower than "average" with premium (93) as well. I'd have to run 89 or 87 all the time to definitively tell the difference.

I can say that if you have any problems with pinging (bad ignition coils, clogged fuel filter, whatever) it's DEFINITELY worth using premium all the time.

 

nowhere in the nissan manual says not using the premium will damage your engine. I'm sure it says will slightly reduce performance

 

87 octane fuel actually has more energy per gallon than 92. Octane number means resistance to predetonation (knock). Any perceived power decrease would be from timing changes made by the ECU but I doubt it would be necessary at a 10:1 compression ratio and bore of this engine. The only way running too low of octane could hurt an engine is if there was knock.

Someone mentioned buy a good brand of gasoline. It all comes out of the same tank!! All the gas stations in your area buy the same gas from the same refinery. The best place to buy gas is at a newer gas station or one that sells a lot of gas. This means that they have newer, cleaner tanks or that they put enough fuel through them to mininize the contaminant level.

 

Before people start spouting stuff about "87 octane having more energy", etc. I will direct you all to the Gasoline FAQ:
http://www.faqs.org/faqs/autos/gasoline-faq/part1/
It is a 4-part document.
This is a USENET FAQ compiled from rec.autos.tech

It is all you ever cared to know (or not know) about gasoline.

 

Dude where do you live? I filled up with Super 94 octane 2 days ago for $1.64 a gallon. Premium 93 octane was $1.62. This is in the suburbs of Philly.

 

this is one of those things people will debate forever. i'm don't think there is concrete evidence either way.

i've heard lower octane combusts too soon and can theorically damage your engine over time. i've read that high octane/premium is a myth - fabricated to make owners of expensive cars feel like they are getting something better, because it requires "premium" gas.

who knows...not me at least! i do know that my manual says a higher octane can provide better performance and TO USE IT! so, i do!

some do, some don't...both claim they are correct. it's a call you have to make.

 

i'm stoked because i just realized a few weeks ago that the gas station next to my house sells Plus for the same price as Premium...no reason not to get it now!

 

Yup thats the best.......in Baltimore most of the gas stations do that.....this is best because it makes the difference between premium and regular smaller...
now all we need is a place that sell premuim for same price as regular...

 

There's a Mobil near me that always does this...but I don't know if it's a good thing. I see it as them basically eliminating 89 octane from the equation and forcing you to choose between 87 and 93.

87 - $1.65
89 - $1.78
93 - $1.78

Obviously no one is going to choose 89 in the above scenario, so everyone that needs or prefers something higher than 87 is forced to pay $1.78 for premium. By simply overpricing 89 by a few cents they almost eliminate it as an option and increase their sales of 93 octane which also means increased profits.

 

Yeah, I think 89 octane is just gravy for the gas companies... not too much point in it (it's only a little better than 87, but 1/2 the extra price between 87 and 93)
I guess 89 made sense back when 91 was "premium" everywhere...

 

Thats a really good point BigD...I never thought of like that..... Very interesting...!!

 

I'm constantly amazed at the people who pay $25k for a car, and then go cheap on fuel. Pay the extra and get the recommended octane. If you can't afford gas for the car, get a Civic.

 

i agree, i just paid 1.53 for 93 at Sams the other day but no matter what the price, i will be paying for 93.

 

There are many points to debate here.... Lower octane fuels, whether it is from a name brand or off brand, have lower concentrations of detergents and more impurities than the higher grade fuels (this is proven as there are specifications that each manufacturer has to meet for each grade of fuel). Also, the lower octane will be more prone to deposit on any hot surface such as intake valves and the top of pistons. This will CERTAINLY reduce performance over the long run and result in detonation. These carbon deposits act similar to a knive edge in a flame.... they will stay red hot and when the next load of fuel enters the combustion chamber, it pre-ignites or detonates. So really this begins to feed on itself.

Now to the gas mileage voodoo... When your engine's knock sensor hears a "knock" or ping (which by the way usually occurs before the human ear can detect it inside the vehicle) the timing is retarded to try and reduce the ping. If this doesn't stop all pinging, the air/fuel mixture is richened up slightly. Both of these will reduce your mpg and overall performance. Plus that overly rich mixture will deposit even more on intake valves. In the long run you will benefit to run the higher octane fuel. You can even fill up with 93 and when you get down to about half a tank top off with 89 if you want to save money so bad. I can't believe that anyone would consider putting 87 octane in anything other than a rental car. The 87 octane fuels out there nowdays is pure sh**. You can even smell the difference.

Also pinging is very hard on rod bearings. I'll put it like this; I have never met anyone with 250k or more on a car that ran lower octane fuels. The engine will just not last that long with detonation occuring throughout the life of the car.

 

From what I've read (and in my experience), the only difference between 87 and 93 is octane rating. There's absolutely nothing wrong with using 87, if that's what your engine is designed to use. As a matter of fact, using higher octane fuels in engines not calling for it can actually cause problems in the long run.

Of course, the Maximas engine has a high combustion ratio, and requires a fuel that burns at a higher temperature. That says nothing of the quality of the fuel though.

 

But to contrary, most of the high end car owners that I see fueling up are getting 87 octane. Go figure.

 

80 million posts have been written at least covering the subject of gas octane ratings. Like Tootsie Roll Pops, the world may never know, but...

Quick things:
- Detonation and knock are not the same thing!!!
- Why would a gas company want cars to get better mileage? Do you think they're fighting electrics and hybrids out of boredom?

"I can't believe that anyone would consider putting 87 octane in anything other than a rental car. The 87 octane fuels out there nowdays is pure sh**. You can even smell the difference."

You must have a pretty good sense of smell if you can smell the difference between regular and premium. Gas varies from station to station and supplier to supplier. If the 93 octane's in a rusty sedimented 30 year old tank there's plenty of 87 octane out there that will test out cleaner...besides, 95% or more of the cars sold and driven daily in this country run quite happily on their "sh**ty" diesel and 87-octane gasoline.

"I'll put it like this; I have never met anyone with 250k or more on a car that ran lower octane fuels. The engine will just not last that long with detonation occuring throughout the life of the car"

I suppose that means that every car that's ever gone over 250000 miles ran premium?

 

What is the cetane rating of the "detonation" fuel?

 

Combustion Ratio => Compression Ratio
10.0:1 is not THAT high.

TK

 

10characters

TK

 

this reminds me of the times at the gas station when i see s600 and bmw 7 series owners filling up on 87 octane to save that $40 every month.

lets just call the $40 a peace of mind in the long run, it couldn't hurt.

 

Thanks for the correction re: compression ratio. A 10:1 ratio is high enough to require premium fuel on many cars.

Please clarify the point of your comment. Are you arguing that we should be able to use lower octane fuel, or ?

 

Well im sure its not good for the engine but won't hurt sence she prob doesn't do hard driving.
The way i figure is why should i put higher than 89 octaine when my knock sensor is broken anways.

 

You know that your knock sensor doesn't work because your engine knocks?

 

He probably got the code from the ecu. And when the knock sensors broken, the engine will retard timing to be safe, like if you were running low octance anyways.

 

Strange logic.
If your knock sensor is broken, you should be filling up with 93 octane, as an extra precaution to keep pinging under control since your ECU is unable to detect and compensate for pinging.
Unless the ECU does something weird when the knock sensor is broken...

 

Honda Prelude VTEC requires 87 octane according to the owners manual. The H22A is far more aggressively tuned than the Maxima VQ, also has 10.0:1 compression.

TK

 

Do you know that honda any engine will run like crap with regular gas. esp if honda had past the 60k mark. I know I have 95 accord vtec. I have friends with lude, they if they put reg gas, the car would go no where the rev would be very rough and the car would ping left to right.

 

A lot of the time they suggest using a higher octane is just to be safe. Theres hardly any difference between running 87 or 93 octane unless your car has a rather high compression ratio, ~10.5:1 or greater. Remember compression isn't linear, the more its compressed the harder it gets to compress. So the difference between 9.5:1 and 10.0:1 is much less than the difference between 10.5:1 and 10.0:1. Generally speaking, on a mildly tuned engine like the Maxima VQ, everyday driving would hardly require higher octane. The precautionary measure for reccomending higher octane, is during bouts of winding out the upper rpms, in mid-high gears. At idle, the A/F ratio is very lean, relative to stoichiometric ratio. Temperature and stability of the combustion cycle are stressed more during a run where you decide to wind out the middle and upper gears, like 3rd and 4th. This is where problems occur, because things in the engine are occuring at a much faster rate, and there is less time between combustions in each cylinder, and less time for the air and fuel to mix.

TK

 

I'll just throw this out there...there was an article in USA Today on the 97 F-150 (when it was new) stating that the engineers at Ford applied not only anti-knock technology into the ECU, but also the opposite. Meaning that the ECU could also advance timing for higher octane.

Ford did this because they couldn't require premium fuel in a pickem-up, however the truck was able to supply a slightly higher MPG and HP if 93 was used.

 

Fuel companies are required by law to put the same additive package in their 87 as they do in their premium. This law was passed to keep people from having to buy higher octane than they needed to get the better additive package.

87 octane fuel does contain more energy per gallon than 93. If your car says to use 87, then use 87 unless it is old and knocks. An engine designed to take full advantage of 93 will have a higher compression ratio which is more efficient. The higher compression ratio engine will take more of the energy from the fuel and put it to the ground. 93 octane fuel does not have more energy, it just allows an engine to be tuned to take better advantage of the energy that is there.

Ted

 

If you can't afford the gas, you can't afford the car.

I must be the only one who doesn't care for gas prices. I only get 93octane, unless 92 is the max at that gas station. I don't even know how much gas is around my town. I NEVER look at gas prices. Unless it's more than i usually pay when fill up.
It costs me about $25 to fill up. $28 if DTE has been saying ---- for 30+ miles
Any more than $28 or less than $25 to fill up when empty and i know that gas prices changed.
I don't care for the company name neither (BP, amoco, kagaroo, or wutever the freak). As long as it's not a mom and pop shop that has like 1 or 2 pumps, i don't care. They all get gas from the same place. When i need gas, i just look for the closest station and pull in and fill up with 93. I don't even look at the price on the board. I try to save money everywhere that's necessary, but i also know that if i properly maintain her, i'll save time and money in the long run. Just in case i keep her for a while. You waste more gas trying to find the cheapest station, than if you fill up right then and there and go on about your business.
It cost me $23 to fill up in Atlanta this past weekend, so i know that gas is cheaper than my hometown. But i don't know how much it cost me per gallon, and i don't care. I know that i covered 400+ miles and still have about 120miles left on the tank according to my trip computer. Try doing that with 87 gas.

You guys are too cheap, or stingy. I guess i shouldn't change my mobil 1 synthetic oil, and filter, at 3000 miles intervals either.

 

I only buy 93, and usually try to buy from the station with the lowest price, just out of principle, though usually that boils down to 1 or 2 stations I frequent more for convenience, not necessarily for price (I started going to those stations because they've usually been the cheapest in the past...)
To me, it's just another cost of doing business. My fuel costs are all recorded in my electronic books, and while they are significant ($229.36 total last month), they're not that bad compared to my income vs. other expenses... and switching to lower octane fuel for cost-related reasons probably wouldn't gain me enough extra $$ to offset the extra risk of engine problems due to pinging. I also use Mobil 1 5W-30 synthetic (STP S6941 oil filter) and change it myself religiously.

 

The Altima 3.5 in all variants also states that 93 octane is recommended, but if it's unavailable a lower octane rating of 87 or higher can be run. www.altimas.net The only car in the vq35 lineup that doesn't recommend premium is the quest, but I believe it has a lower compression ratio.