ZeroPSI

What octane do you usually fill your TL or TL-S up with?

Bxscig

93.... that is the only thing that is 91+ in nyc or at least that i can find.

Bareback

91 to 93 at Chervon and Sunoco

kcroberge

93 only

ou sig

premium only - anything less and you will have knock problems during hard acceleration and poor gas mileage

dark inspire

91 for me

kaih

I've been using 87 octane for a while now. The only noticeable difference is a slight loss, which might be just in my head, of power under hard acceleration. These engines will adjust to lower octane and will not knock. And I'm getting better gas mileage with 87 than I did with 91 (we don't get 93 in California).

ZeroPSI

we don't even have 93 at pumps around here. 91 is our highest, I usually use 89 - 90.

dark inspire

that may be the case, but it has longterm effects from what ive read

ou sig

you will start to knock...you are just like my dad - he wouldnt put anything other than 87 in my mom's '02 Avalon (requires premium) - she called me a week ago and complained of "noise" when she accelerated. I told her it was for sure the 87 gas. On the next tank she filled with 93 and it hasnt happend since.

My point is, she has 60k miles on the car, so it took a bit to catch up. and you are right, the computer will adjust for the lower octaine, but it is not good for the engine for the long haul. The computer adjustment is for if you accidentally fill up 1 time with the lower octaine - but you should never run less than required consistently - its not worth the dollar or two you save/tank.

Gingerbreadman

I always use premium gas (usually 93 around here) but am interested in this 89 octane issue. What are these "problems" that are caused by running the lower octane gas and please list reliable sources. Please don't take me rude, but I don't really care what your buddy "Bill the Mechanic" said unless Bill has done some sort of "scientific" experiments to prove his hypothesis. If our cars will in fact adjust the timing etc to run the lower octane, and the "spark knock" is eliminated, what is the harm. Actually I have read articles that show that regular unleaded actually burns a lot cleaner in the engine than premium and I would guess it would also burn cooler... which seems like a good thing to me.

Please educate me... one that knows the details. Be as technical as you like cause I will look up what I don't understand. Thanks.

drcookie

Premium - 91 in California. Had never tried anything below that.

kaih

Where did you read that, on marketing materials from oil companies.

I pulled up one quote, there are other sources.

“The car will run on regular fuel without damaging the engine,” said Martin Peters, manager of public relations for Porsche Cars North America Inc., the Atlanta-based subsidiary of Porsche AG, which like other automakers recommends premium fuel for all of its cars for “optimum performance.”

http://www.msnbc.msn.com/id/7518098/

ou sig

My experience is with my own car and my mom's car - both have similar engines with a higher compression that "require" higher octaine. My mom used 87 untill her engine started knocking bad - it immediately stoped when she used premium - that seems like a pretty obvious test with results.

Now saying that will happen 100% in our cars is ridiculous, because every engine is slightly different and our 3.2 vs. the Avalons 3.0 is also very different. I dont believe there will be a test with 100% accurate results across the board. So if you want to save the few bucks/tank, be my guest - just dont be surprised if you have engine knock sometime down the road with lower performance all the time.

kaih

The car was always filled with 87 for three years and never knocked. Then one time it knocked. You filled up with premium and the knocking stopped. You made the assumption that it was the 87 grade gas. It could have been a lousy tank of gas(water in tank). If if the car continued to knock after multiple fill ups of 87 from various gas stations, then stopped after the premium fill I could believe it more. But it happened one time then it went away The use of premium may have been a mere coincidence. Fill up the car again on 87 and see if it knocks.

Another thought is that the car needs servicing or has an ignition problem. I'm not convinced that the gas grade is the culprit.

progz

If Acura says to fill it up with premium gas only then there could be a very good reason behind it. I don't see the cost benefit of saving $0.20/gallon. BTW..I only use 91 Shell.

kaih

It won't make the maximum or advertised power on lower octane gas. But it will not hurt the engine to run lower octane.

ou sig

you are right pretty much - I dont really know if the knocking is very bad or not for an engine (I cant imagine it being good for the engine). Also, she had the knocking for a while - she thought it was bad gas so she switched stations and the same thing happend. That is why she finally called me because my dad was too stubborn to admit I was right (hahaha). But now she has 0 knocking with premium, and the car is well maintained

progz

If the car is not designed to run on lower octane why take the risk. That's the same reason why you go with the big companies like shell, mobil....instead of arco or the no name brand in your neigborhood. It's because of the impurities that you might get from their gas. Well I guess its really up to the car owner. If he finds it satisfying then so be it. IMHO, I'll spend an extra 0.20/gallon for my $13K car. I don't have the $$$ to do mods but I have 0.20 cents to spend to keep my engine running.

fsttyms1

exactly. honda designed the car to be most powerfull and efficant at 91+ octane. will it hurt the engine? it is possible (all it takes is 1 knock) is it likely no. you spend this much money on a 30k car, why cheap out on the extra $$ to make your car run the way it was designed. i for 1 get much worse mileage with 87 (had to use it a few times) than with 93

ou sig

my point exactly - even my stubborn dad finally realizes that engines are different now, and premium isnt a waste but a necessity for some cars for them to run properly

kaih

They are different which is why you don't need the higher octane ratings. Most cars made from the early 80's and before that were carburated and had mechanical ignition systems. Those cars could not self adjust timing. Todays cars habr knock sensors and computerized ignition systems which can compensate for different conditions such as gas octane. Temperature, altitude and humidity also affect the engines abiltity to burn fuel and the cars systems can compensate for these factors as well.

The main purpose of octane is to control knock, by burning slower. It does not make more power by itself. The extra power comes from being able to advance timing in the ignition without knocking and thus make more power. Otherwise the higher octane does nothing else.

If you have a car today that is knocking it's probably coming from carbon deposits on top of the pistons which increase compression ratios. The higher the compression ratio the higher octane you'll need. There is a limit to how much the ignition timing will retard to control detonation. So if it's knocking it might not be the gas but your engine is needs to have the carbon removed. If that Avalon ran fine for three years and 87 then it started to knock that's probably the culprit.

You can put whatever you want in your gas tank. If premium makes you happy, fine it makes the oil companies happy too. But the fact is the car will run fine on regular. Show me a car who's engine has blown due to using the wrong grade gas. And don't quote me what some obscure mechanic said. Most mechanics only know what the computer hooked up to the car tells them.

kaih

They designed the car to be a luxury sedan. I don't recall headers, intake, springs sways, pullies exhaust, 19's and superchargers part of the design, but people change those all the time with no ill effect either.

RBallman

Only 93 is good enough for my DGP/Camel baby

ou sig

I dont doubt your knowledge at all - Im just saying a lower octane (Can) cause engine knocking and reduced performance in some modern usually smaller higher compression engines - will it blow up your engine? I would say no - but the Avalon quit knocking with the premium gas and hasnt since - kinda makes me think that the regular gas had something to do with it. Most of us are saying, the extra few bucks is worth it to have the best performance and no knocks that could come with the regular fuel. And my dad's stubbornness is understandable because like you and he said, older cars didnt need premium at all, and anything but regular fuel was a total waste of money in older cars and is in some modern cars also

fsttyms1

i cant show you a engine that has blown (recently but it has happened to me in the past) and NONE of us here have stated they can. BUT what i can show you is ALOT lower mileage, and when you have to fill up the tank almost every day like my self REGULAR gas (87) costs alot more than 93. i could also show you my car is slower with it too. YOU can put what ever you want into your car, and i will continue to put in 93 because it costs me less and i get better performance

SaNJoSeTLRydEr

i usually pump 91..but when im low in $$$ i pump 89....but usually 91 only..

progz

I also have a 03 Odyssey and the recommended fuel is 87 regular. But I did heard from Ody owners that putting high grade fuel gives the engine a better performance. I haven't tried it myself because Ody is not fuel efficient. I once own a 99 Camry and the engine knocked. I don't know if it was caused by the fuel type but based from that experience I'll just follow what the book says. And it is my belief that Acura has a very valid reason for putting a label on our gas tank "Premium Fuel Only." If they think that Regular Fuel will work then they should have put a different label.

ryanconk

My silver lady gets 93 octane here in NY. that's because it's hard t fid place with 91.
Occasionaly, I fill it with half 89 and half 93 just to save
But most of the time, I give my baby the love that it deserves!

brakejob

to echo everyone else, when you drive a premium car why go cheapo on the gas?

progz

Very well said

kaih

These are the same people that shop the internet for the absolute cheapest price and want to do a group buy on gaskets to save $4 in shipping charges.

Plus a $150 saved in gas a year is 10 more cases of beer for me.

kaih

If the car was set up to run on 87 octane you will not get any benefit from running premium. Cars that were set up to run on premium advance ignition timing which takes advantage of the higher octane. A car meant to run on 87 will not be able to take advantage of this unless you use a chip or programmer to take advantage of it.

kaih

I've stated the car does not make as much power with 87 grade than it would with premium if it was designed around running premium.

My point is simple, you can run regular gas in a car that says premium without damaging the engine.

If the car knocks you've got other problems, don't blame it on the fuel grade.

kaih

The engine should be able to compensate for the knock. If it knocks there is probably something else going on.

That car most likely has carbon deposits on the pistons increasing compression and the engine management can no longer compensate enough.

I never said that. Premium fuel was needed in some older cars. High performance cars of the 60 and 70's regularly had high compression engine 11:1 and higher. The higher the compression the higher octane you needed. Premium leaded fuels (no longer availavle) had octances ratings of 100 or higher. Older engines back in the day were lucky to last 100K miles. The ignition systems were controlled by mechanical weights, no enhanced engine management by an onboard computer.

Chauncey

I filled up the otherday with 87, I tagged the tripometer and will monitor the mileage. I will next fill it up with the most premium I can find (93 most likely) and will report back on the mileage

As for why wonder if it will damage the car running 87, well I think its a great question. Gas prices are rising and the where I am at (Chicago) the gap is closer to .30 on the gallon. Thats close to 5 bucks a fillup. or 260 bucks a year if you only fill up once a week (I fill up more).

So say average driving with extra (holidays, events, etc...) you probably would end up spending close to an extra 350 a year for the premium gas.

not much to some.....blows the car budget for others. I dont think some of you should be blasting people for trying to save a dime where they can. As you can see I filled up with 87 so I am one of those people. I save where I can so I can spend what I want.

If it does make a significant difference I will never use low octane again though. I just read in so many publications that higher octane is a rip off. This is the first premium car that I have owned so I dont want to screw up the ride .... how sweet it is

Black3.2

i use premium which is 93 i think i used regular 84 octane and my engine started to knock. gotta pay more for our engine

MeldyS26

i used to pump regular gas, but now i switched over to premium 93 and i can feel that the engine runs smoother

Mr Hyde

Did you expect him, or anyone else to continue filling up with 87, and drive around despite the engine knocking the whole time?

NOT true...Cars designed to run on 91 do NOT have a baseline timing curve set to 87 which is then advanced only when running premium. You have that backwards. The cars timing timing curve is set at baseline to run with 91 octane. If you run a lower octane, then the timing is retarded from baseline to compensate. Keep in mind, the computer will not retard timing just to the point of knocking, or pre-ignition, but will overcompensate, and retard timing even further to be on the safe side.

I have seen a few article in publications dealing with what a waste it is to run 91+ in a car designed for 87, but I have also seen the same when talking about the reverse. Every time, the drop in mpg alone meant in the end that the difference in price between the 2 amounted to pennies, and was a small fraction compared to the difference at the pump. If you use more of the cheaper gas, its not much of a savings. This doesnt even take into account the issue of decreased power, and performance.

If your car is knocking, your sensors arent keeping up, and any knocking whatsoever is a very bad thing.

These cars especially the Type-S with its even higher compression over the TL-P run the best, and at their most efficient with the recommended octane. If you own a TL-P, or a TL-S especially, why waste the thousands on the added perfomance if you are going to just water it down with lower octane gas?

There is also the fact that most stations do add more detergents, and additives to their higher octane blends which help combat carbon deposits etc, and keep your engine running cleaner longer. In one users case, that could easily lead to carbon deposits, etc which would then cause knocking.

If a car is designed for it, you should run it. You say find me a blown engine due to running lower than recommended octane. I say find me any respected mechanic, or automotive publication that would recommend running lower than recommended octane.

Mr Hyde

Read those publications again, and I am sure they are referring to running premium in a car designed for regular which is a total waste.

In a car designed for 91+, running anything lower will cause over retarded timing, a drop in performance, and in the worst case, can lead to knock. May not be an issue cruising on a free flowing highway. On a hot day under load, etc it definitely could be, and all it takes is a few seconds of knock to cause major damage.