T-One

I just bought a '99 SE-L. I calls for premium gas. Has anyone used regular unleaded? What are the consequences? Gas in Los Angeles is getting a little on the expensive side.

vmok

Use premium...

There's a knock sensor in the Maxima, so using regular won't hurt it. Your car just won't be as powerful.

If you're trying to save money, I don't think that's the right way to do it. When you use regular, the computer is more prone to sense detonation, then retarding timing and stuff. The engine isn't running at it's efficiency peak, so you'll probably end up using more gas. Albeit more CHEAPER gas, but you're probably better off just using premium and letting the engine run at it's most efficient peak, which will return optimum gas mileage, etc...

-V

_DRU_

there a quite a few large threads debating the use of Premium vs Regualr. use the search function on the top right hand corner and you will find exactly what you need.

_DRU_

there a quite a few large threads debating the use of Premium vs Regualr. use the search function on the top right hand corner and you will find exactly what you need.

Eric L.

Well, I personally think it is a personal preference, as the increase in gas mileage that super gives over regular is not enough to justify the cost increase. As for performance, if you can feel the difference and it matters to you, then use super. I personally cannot really tell the difference (it is there, but not a big deal). And no, you will not damage the engine at all if you use regular.

Do a search for type of gas. The info is all there.

SWEETSOUND2001

iTrader: (30)

i run premium

BippuBenji

iTrader: (4)

Yea, just use premium, don't try to take any shortcuts.

Kevin Wong

I got better gas mileage running on regular, but I always fill with premium now. The car feels little lighter to me which probably means I'm getting more power. I'm currently getting around 28-30 MPG but whenever I have the car serviced, I'm right back down to 24-26 MPG.

Vitaly O.

is not worth the trouble just use premium because the book said so

Matrix

i use premium too


but ive heard stories that the gas at the pumps are all the same. They just label it differently. It might all be 89 octane for all we know

CandiMan

iTrader: (1)

Between the two grade (.10-.20) after filling up the savings will probably be about $1.50-$2.50 per tank depending where you live and if you're filling up when empty (which I do and recommend, seems as if I get more MPG with a complete fill-up instead of $5 here then $10-$15 there) Besides a house and kids your car is a big investment so saving $2 per fill not going to make or break me. Of course I can't speak for others, you have your own personal reasons. This gas hike gotta stop sooner or later, I hope.

VQ Quick

You can use regular but you won't be able to push the car as hard and since your acceleration will suffer slightly you may be inclined to push the gas a little harder to get the car in motion. High revving of the car with regular rotgot gus can have dire consequences. Drive like a granny and you'll be fine.

DARTHSWAN

Really, that's interesting. When I was dumb and put regular in my car the gas mileage was horrible. From that day, I promised to always use premium. Use it, it will save you money in the long run.

K

jiaxima96

I finished a few tanks of premium gas, and compared to regular gas that I used the most. I never pushed the acceleration pedal to the floor. However I do sometimes push it hard. It is difficult to compare the two, as when it gets hot I leave A/C on longer, etc. My feeling so far is there is no difference to me. Idling smoothness, acdeleration (not all the way to floor), MPG and so on. I believe there should be some difference that some meters can detect.

Eric L.

Exactly. The difference is minimal. Maybe a few horsepower, but hardly noticeable. If you take the car to the track, you might notice it in the run time, but not with the "butt dyno". Using premium is a personal choice. Regular DOES NOT harm the engine and the owners manual explicitly states that regular is acceptable (would Nissan say that if it were bad for the car? nope.)

So for all those people who insist on using super, that's fine. But I just wish people would stop insisting that one MUST use super in their Maximas.

Nick97SE

iTrader: (14)

I agree with Eric L. I've only had the car for a month or so, and I use regular. Even in my old Maxima, i used regular, and I'll continue to do so as the gas price keep going up!

-Nick

MaximaGold

I don't think they(oil companies) will be happy until it hits 3.00 a gallon. Its like cigarettes you say you will quite when they hit 2.00 a pack, then 3.00 a pack but your still smoking. Same with gas, it will keep going up, and you will have to buy it. 15 cents a gallon difference is not much, but 2.00 to 3.00 is.

I switch back and forth with the high and medium grade I guess I have 90 to 91 octane in there most of the time.

I received an e-mail calling for a boycott of Mobil/Exxon
being that there the biggest. Stop buying gas from them and they will be forced to lower prices. And then you start a price war. But when was the last time this country was able to stick together for the good of everyone. Hum was it the revolutionary war, maybe world war II.

NYCe MaXiMa

iTrader: (9)

Boycott won't do a thing, yes it might lower prices for a little bit, but how much lower can they make them, only as much as other tiny manufacturers are selling them for.. regardless, there has been many threads on the Org about the whole oil situation check them out, very informing.. Oil supply is very limited, nd at an all time low, as the demand is at an all time high.. Supply is decreasing rapidly and demand is increasing at the same rate.. Increasing production will only help you run out faster..
Anyways, about the gasoline thing, I have tried filling up with regular and premium but it's only been premium for me for the last year or so I had the car.. I just feel better about it knowing I am giving it the best thing. And the 10-20 cents difference between gas prices isn't that much when I put in 10-12 gallons. But you won't really mess your car up putting regular in it, especially a max, these engines can probably run on urine that's how good they are

vmok

I guess to be a little more explicit, you are correct. I don't notice any additional power under normal driving whatever gas I use. But I do recommend premium for the following reason, detonation is bad for the car.

When it is warm or hot outside, the engine is more prone to detonation. The car's timing is set, advanced, and optimized for 91 octane fuel. However, the knock sensor is a feedback system. It usually takes detonation before the system knows to retard timing to eliminate the detonation. Detonation is had on the engine, as the engine is not firing at the right time. Normally, the mixture of air in fuel in the engine doesn't ignite until the spark plug starts the process. During detonation/ping, the mixture ignites before the piston hits the top of it's travel, therefore, that combustion is working against another cylinder which had fired after the piston has hit top dead center. (ok, technically, the spark fires slightly before top dead center, so that the flame kernel and expansion hit's it's optimum as soon as the piston hits the top of it's travel). There's stress placed on the crank, valves, pistons, rods, etc... In hot weather, detonation causes more detonation, and more and more retard in the timing. Why? The more the computer retards timing, the hotter the engine gets.

Also, many people think that premium gas makes more power. The octane in the gas doesn't make more power per say. It's a measure of the fuel's resistance to detonation. By using a fuel more resistant to detonation, manufactuers are able to tune the ecu to advance the timing more, knowing that the engine won't fire out of order, giving more power. Under hard throttle, the car is dumping preset amounts of fuel into the engine. Under these conditions, the car runs a little richer (and it run richer at idle as well.) However, under consant cruise, the computer is set to lean out the mixture to the point right before detonation is heard by the knock sensor. However, as the engine hears knock, it'll need to retard the timing, causing a slight power loss, and therefore, more throttle to make the car go the same speed. You'll probably actually get more engine knock rolling on the throttle rather than mashing it. I know I can hear it on my car when I roll on the throttle after cruising a while. This is because the ecu has leaned out the mixture (and a lean mixture detonates more easily).

However, a lean mixture isn't just more efficient, it also generates more power. So, for those people who have the resources, a Apex S-AFC air/fuel controller can get you power under careful tuning. By leaning out the fuel under higher RPM's, you can get power gains as the factory ecu's tend to dump more fuel into the cylinder.

Finally, you bought Nissan's flagship sedan. If you notice, most manufacturers offer a 4cyl and a v6 in their vehicles (i.e. Camry). If you take note, most manufacturers recommend regular fuel for their 4cyl engines and premium fuel for thei 6cyl engines. Why? Because they know people buy the 4cyl engines for economy, but presume that if people are willing to pay for the 6cyl, then they're the type willing to pay for the better gas. Filling up premium fuel in a car not designed for premium doesn't help get any more power either, as the computer doesn't know to advance the timing to take advantage of the more ping resistant fuel.

It's your car, and you're right, you can fill up whatever fuel you want in your car. And to generalize, you're also correct that in most modern cars, regular fuel will not damage the car, as almost every modern car utilized a knock sensor. I'm no expert, but by having a basic understanding of how the octane affects the car, I feel better using premium fuel instead of regular fuel in my Maxima for the long term longetivity of the engine.

Just my $.02 and I'm in no way trying to offend anyone!

Daniel B. Martin

Have you tried this? If you do, please post the results. This idea is even better than the boycott.

NYCe MaXiMa

iTrader: (9)

Hey, I'll try it, just not on my car ... anyone want to volunteer their max?

Shayyadin

Okay, here's how I look at it, right? You shell out SO MUCH money on buying your ride that $2.00/tank is a drop in the bucket. You dished out a $hitload of G's when you bought the car, you pay a bunch more with every little mod.

You pay $170 for a Stillen intake, let's say. Or for a FTSB or clear tails, or even for a repair. All that money. Then you put less-than-recommended gasoline in?

No entiendo, senor!

If you're here, you probably think quite highly of your car. You probably even have named it, dedicated something to it, talk to it, or do all of the above.

If you're gonna treat it like royalty, why give it the common man's food? Especially when it requested good eats by name: 91+ octane unleaded.

That's just by two cents per gallon.

Shayyadin

vmok

Reading your post made me laugh, along with Dan Martin's post above. Keep it up peoples, these are the kind of posts I live for

-V

Eric L.

EXCELLENT points. Your rationale for using super unleaded could not have been stated more clearly and objectively. FYI, I use super unleaded as well, but believe like you, that regular will not necessarily ruin the engine (so I do use regular every so often, but I don't feel bad about it). Thank you for going through the points. It is so much more refreshing to read this sort of technical advice rather than "my grandfather used super all his life so I will too" or some other drivel like that.

Enjoy the ride!

maxnewbie

I have read all these postings and have noticed that no one mentioned using MID-GRADE gas. I mean, I wouldn't drop all the way down to just regular, but would mid-grade be acceptable. I have always used mid-grade in my other cars including a Mitsubishi Diamante that is considered a high-performance sedan and it never knocked with mid-grade. In fact, it drove just fine. The power was always there, and it only put out 175 HP. By the way, I am currently getting 26 MPG using Premium. I am going to test and see what I get with mid-grade and report back to you guys. P.S. Currently, I am paying $1.69 per gal. for Premium 91 octane gas.

Dreizehn

iTrader: (4)

Check with Daniel B. he was saying that low octane gas ignites too early, which may cause problems in the long run, correct me if I'm wrong... Please...

Daniel B. Martin

I don't think I ever said that.

Fuel with inadequate Anti-Knock Index is more likely to burn in a rapid and uncontrolled manner. It may burn with two flame fronts instead of one. Uncontrolled burning results in dangerously high combustion chamber temperatures and pressures. This results in excessive thermal and mechanical stresses resulting in broken piston ring lands, cracked piston crowns, etc.

Eric L.

Just so people don't misinterpret your definition of "inadequate Anti-Knock Index", I'll state it again. The ADEQUATE (i.e. acceptable by Nissan) octane rating for gasoline for 4th gen Maximas is 87, not 91. If you use 91, you may get a few more hp, but only a few, and only if you floor it all the time to get every last hp from the engine.

-E

jiaxima96

Having read these post, from other sources, and the owners manual, based on my driving habit, I'll still fill with 87 most of the time, and sometimes 93 just for a change. I just drive between home and work, and will never want to squeeze a few more HPs to run faster.