Octane ratings, etc.

[Bnystrom]

Here are some explanations of octane, it's effects and what you should use in your engine:

http://en.wikipedia.org/wiki/Octane_rating

http://www.faqs.org/faqs/autos/gasoline-faq/part3/

http://chemistry.about.com/library/weekly/aabyb100401.htm

The last one specifically talks about how running higher octane fuel than necessary can be harmful. Initially, they state "In fact, using a gasoline with too high of an octane rating may cause damage to the emissions system.", They go on to elaborate that it results in incomplete combustion or as they put it "sends unburned fuel into the emissions system and catalytic converter". Incomplete combustion will also result in deposits in the engine, though they don't specifically state that. They do go on to state: "This puts unecessary stress on the emissions system."

The bottom line is that they all agree that there is no advantage to using higher octane fuel than an engine requires. It doesn't produce more power, it doesn't clean your engine and it's not "safer".

Andrew wanted evidence, now you have it.

[ba_feitl]

... I've got this can of worms here...
... anybody got an opener...

oh thanks Bnystrom

:D

[Andrew]

No need for a can opener.

I cannot believe you made a whole extra thread just to not understand. You probably realized you were prove wrong on too many accounts and had to sacrifice some dignity, and pick out the only thing I did not shut you down on. Either you don't understand the emission system, or you don't understand octane.

I wonder why they didn't say it would harm your motor. Interesting. I never said it would not harm your emission system, did I? The emission system is designed to be abused. You're more likely to get oil deposits in your motor, than actual fuel.

Naturally, running higher octane will destroy a cat faster. Try running race gas. It will destroy your cat and possibly your narrowband.

Let's take a look at something, called the oxygen sensor. It measures the amount of gasoline, compared to the air. Whether you use a narrowband, or wideband (which do the same thing, but one reads a much broader spectrum to a fine point). For this, we are going to pretend you have a wideband. Remember, perfectly stoich is 14.7 AFR. If you had that much unburned gasoline coming out, you would trip the sensor. It would throw a code, short out, or adjust. Depending on the amount. If you were to place a wideband (a true, not a tail sniffer) into an unmodified car. Run it directly on 87, and then 93, the air fuel ratio would be required to change assuming that there was unburnt gasoline in the exhaust stream. Unforuntalely, octane does not affect air fuel ratios. The specific gravity of the fuel (ie .735 for Sunoco GT plus 104), or even the temperature of the air will. But not mere octane.

You went through the trouble of making a new thread with the only detail you could work with, to provide a fact that it would harm the emission system. When you stated the motor would be harmed. Wait, your fact stated the emission system. But you said the motor would be harmed. Either that source is not very thorough, or you're wrong.

Either provide proof that the motor is actually harmed. Now, dont come up with some useless thing such as "there are atomized fuel in your EGR!!!". I'll admit that there are. You take that *slight* amount of unburned gas, and put it back into your intake tract. Which, if were a real problem. You would never see oil buildup in your intake manifold or exhaust manifold (on steeper cases). The fuel would wash away the oil. The carbon will always be there, since the majority of gasoline is carbon.

I'm aware I've gotten under your skin, but keep in mind this site is designed to help people out. I didn't get into the details in the very begining, but you continued to pursue your course. I'll give you credit, you're quite stubborn and you are begining to use some evidence. Going around trying to pick a fight isn't what this site is for.

Before this thread you had remained relatively mature about the whole situation. I respected that, not many people could take the abuse I put on you and not call me names or start childish bickering. You always stayed true to the point. I'd appreciate it greatly if you kept it that way.

-Andrew

[ricerrx7]

You bash someone for incorrect facts, yet some of your "facts" are wrong too. The O2 sensor doesn't measure O2 COMPARED to anything! It measures the amount of O2 in the exhaust period. It has NO way of knowing how much CO, NOx, CO2, or HC's are in the exhaust (wideband is a little better based on it's ability to measure the temperature of the exhaust).

AND, we don't have EGR's on our cars.

[Andrew]

You bash someone for incorrect facts, yet some of your "facts" are wrong too. The O2 sensor doesn't measure O2 COMPARED to anything! It measures the amount of O2 in the exhaust period. It has NO way of knowing how much CO, NOx, CO2, or HC's are in the exhaust (wideband is a little better based on it's ability to measure the temperature of the exhaust).

AND, we don't have EGR's on our cars.

I was referring to motors in general in terms of the EGR. As for oxygen sensors they measure something called the air fuel ratio. Even narrowbands do this, only 1/5 as effecient as widebands.

http://auto.howstuffworks.com/question257.htm

A wideband does not measure the temp of the ehxuast, that's an EGT.

edit-The wideband uses temperature to read and respond, is that what you meant? The narrowband still measures the AFR, just not on a large scale. It can't pick up hydrocarbon type, exhaust temperature, back pressure, etc. but it's still attempting the same thing. This is also why I said to pretend you had a wideband, to avoid any sensitivty comments. Maybe I wasn't clear enough on that. My wording in the last post was a little sketch, but I'm pretty sure you got the picture. And on top of that, not having an EGR will then take away from the original intent of this thread.

-Andrew

[focusXD]

http://web.umr.edu/~tlpgx2/crap/grimace.jpg

[Bnystrom]

You bash someone for incorrect facts, yet some of your "facts" are wrong too. The O2 sensor doesn't measure O2 COMPARED to anything! It measures the amount of O2 in the exhaust period. It has NO way of knowing how much CO, NOx, CO2, or HC's are in the exhaust (wideband is a little better based on it's ability to measure the temperature of the exhaust).

AND, we don't have EGR's on our cars.
As he has done all along, Andrew posts a lot of figures and spews a lot of buzzwords, but it's apparent that he has little understanding of the things he refers to. Anyone can post a few paragraphs of incoherent babble, irrelevent facts and incorrect interpretations and impress some people, but it's all just noise if you don't understand what you're talking about. This is no different than the oil thread where he made incorrect claims about the SAE, among other things.

As for the purpose of starting this thread, it was to present the facts to others here, rather than have them fall for Andrew's misleading posts. Forums like this can be invaluable, but not if they're overrun with incorrect information. People are free to believe whatever they wish, but at least the information is here if you want it.

[Andrew]

Way to be redundant. As stated before, provide proof to support yourself. Then tell me I don't understand it and that all I do is babble.

-Andrew

[focusXD]

i believe you've misunderstood what andrew meant by "safer". its safer to run the higher octane because it will keep your engine from knocking/detonating/preigintion BUT should you not have any power adders requiring that of you then it isn't any safer than running the lower octane. try running nitrous with 87 octane and see what happens.

no where did any of thos article state anything about higher octane being harmful to the ENGINE which is what you've been insisting upon in the other thread. you've only shown how it can cause damage to the emission system.

also, i don't understand why someone who seems to be so "intelligent" is obessed with powerchips. you've mentioned it i don't know how many other times in the other thread. someone who thinks putting one of htose on a stock engine will gain you more than I/H/E is a damned fool.

you aren't backing up anything you stated in the other thread. so put up or shut up alright? i'm tired of this stupid bickering that is getting nowhere except andrew irriatated lol

[Andrew]

Well, technically he hasn't been wrong about anything. A few little things, but nothing serious. Bynstorm and I have been arguing over a lot of little things, where both of us have been correct. We talked a bit and decided to stop the bickering contest, it's pretty pointless.

I'm not sure what the deal is with the whole powerchip thing is though, so I won't comment on that.

[Ugzz]

wow actually being solved instead of pent up and preparing for future aggressions..

Can you feel the love? Good stuff =)

And hey, in your "bickering" as you put it, you both provided solid info, reading material, and links. So hey, if people want to learn, they can still read these threads and learn a thing or 2 =)

[Bnystrom]

Well, technically he hasn't been wrong about anything. A few little things, but nothing serious. Bynstorm and I have been arguing over a lot of little things, where both of us have been correct. We talked a bit and decided to stop the bickering contest, it's pretty pointless.

Yeah, Andrew and I have come to an accord and the battle is over.

I'm not sure what the deal is with the whole powerchip thing is though, so I won't comment on that.
The Powerchip contains re-mapped timing and fuel delivery curves. I don't think it changes the valve timing on CVVT engines, but I'm not sure about that. Basically, it re-tunes the engine to take advantage of higher octane fuel. It can advance the timing more than the stock ECU chip can and richen the mixture more if necessary. If you don't use higher octane fuel, you won't see much advantage from the Powerchip (it will simply retard the timing to prevent pinging), though at least in theory, it might provide slightly more power in part-throttle situations where octane rating is less critical.

i believe you've misunderstood what andrew meant by "safer". its safer to run the higher octane because it will keep your engine from knocking/detonating/preigintion BUT should you not have any power adders requiring that of you then it isn't any safer than running the lower octane. try running nitrous with 87 octane and see what happens.
Let's stick to comparing apples to apples, shall we? As soon as you start talking about nitrous or forced induction, it's a whole different ball game.

no where did any of thos article state anything about higher octane being harmful to the ENGINE which is what you've been insisting upon in the other thread. you've only shown how it can cause damage to the emission system.
It's simple. If running higher octane fuel results in (more) unburnt fuel entering the emissions system (causing the damage they cite), that is a clear indication of incomplete combustion. Incomplete combustion will lead to more deposits in the engine. It makes no difference if the incomplete combustion is due to a poorly tuned (or malfunctioning) engine or from fuel with too high of an octane rating; the effect is the same.

also, i don't understand why someone who seems to be so "intelligent" is obessed with powerchips. you've mentioned it i don't know how many other times in the other thread. someone who thinks putting one of htose on a stock engine will gain you more than I/H/E is a damned fool.

You seem to have an odd definition of "obsessed". I've probably made mention of them in passing all of a half dozen times in the past two years (and that's on two forums combined). I'd hardly call that an obsession.

Perhaps you're also thinking of something else. I'm not talking about the "snake oil" junk you see for sale on Ebay. A Powerchip is a re-programmed ECU chip that will produce performance gains, but it requires that you use premium fuel to get the maximum results. They're also not cheap. Their engineering seems sound and their claims are modest enough to be realistic. If you want to read about it, go here:

http://www.powerchipgroup.com/index.asp

I'm not endorsing the product, as I don't use one and I don't plan to. It just seems like a simpler, sensible alternative to dumping a lot of money and time into installing intakes, headers and exhausts (I/H/E), etc. that apparently provide minimal gains with the Beta II engine, though it's not as much fun to do if you like working on cars. There doesn't seem to be any agreement as to what I/H/E combination works best, either, so one can end up wasting a lot of money on products that provide little, if any gain. Moreover, some people seem to be more interested in intake/exhaust sounds and "bling" than actual performance, which is fine if that's what you want.

FWIW, I learned a long time ago that if you want to get the best performance from modding a car, it makes sense to find out what products people who race them are using and/or buy parts from companies that develop them for their racing teams. These are the people who are doing the real performance research, as opposed to companies that just make I/H/E parts that fit, then make unfounded claims that they will improve performance. If a company cannot provide hard data on the specific engine you're modifying, there's a strong chance that their products won't provide much - if any - benefit. Of course, not all racing parts are suitable for the street, but often race part manufacturers will also have "street" parts with demonstrable benefits.

Do whatever you want to your car, it really doesn't matter to me. You're only limited by the amount of cash you have kicking around and the time you have to put into the project(s). However, you can quicky reach the point where it makes more sense to just sell the Elantra and buy a higher performance car. ;)

[06elantra]

i dont mean to start a whole new arguement,
but i feel the need to throw my 2 cents in (having worked in petrol stations, i know all the fuel promotional blurbs that you get..)
anyhow

efi engines are able to adjust the amount of fuel via the ecu going throught the injectors into the cyclenders to be burnt.
i have found in my experience, that higher octane fuels contain more energy than lower energy fuels, thusly, the ecu knows this as well - thru use of the engine sensors.
It will adjust the amount of fuel being added into the mixture to be burnt.

i agree that running too high an octane fuel can be bad for the engine - but i think that also comes under general fuel system maintanence as well.

My 1987 EFI Ford Fairlane's Ecu can do this trick - and thats a pretty old school Bosch EFI systems.
Surely if a car 20years old can adjust the timing, spark advance and fuel mixtures, then our cars being much much newer should also have this feature by default - as im sure it plays a part in how economical our cars run.

again - dont mean to start another arguement over it, but wanted to put my 2 cents in :)

(oh - btw, here where i live, the highest octane fuel i can get is 95 RON... at least south of me you can get 98 RON fuel.. and thats GOOOOOOD stuff!)

*gets back in box*

[ricerrx7]

It has nothing to do with how much is going in, but what is going in. So the ECU's ability to control the AMOUNT of fuel going in has nothing to do with the octane discussion. Now, a car that is tuned from the factory to run on 93 octane can sense if you put in 87 octane because of the knock sensor. It senses the detonation, and retards the timing so that the engine doesn't destroy itself. BUT a car that is tuned from the factory to run on 87 octane WILL NOT advance it's timing to make use of 93 octane. You can retune the ecu so that it can make use of it, but without doing so it will be pointless, and will not burn completely.

[06elantra]

actually, i thought the amount of fuel going in is relevant to the octane rating...

the ecu will need to put 'more in' of a lower octane fuel to get the same burn as a higher octane rated fuel...

as i did say in my other post tho, too high an octane fuel can be bad for the car - overheating is something i have personally had experience with due to using too high a octane rated fuel..

*gets back in box again*

[Andrew]

It has nothing to do with how much is going in, but what is going in. So the ECU's ability to control the AMOUNT of fuel going in has nothing to do with the octane discussion. Now, a car that is tuned from the factory to run on 93 octane can sense if you put in 87 octane because of the knock sensor. It senses the detonation, and retards the timing so that the engine doesn't destroy itself. BUT a car that is tuned from the factory to run on 87 octane WILL NOT advance it's timing to make use of 93 octane. You can retune the ecu so that it can make use of it, but without doing so it will be pointless, and will not burn completely.

Correct. The only system known to advance timing based on octane is the late 70's early 80's Chevy trucks. They run up timing until they sense knock, and then pull timing back a few degrees. I'm not sure what exact years, but the 81 had this feature.

[Bnystrom]

actually, i thought the amount of fuel going in is relevant to the octane rating...

the ecu will need to put 'more in' of a lower octane fuel to get the same burn as a higher octane rated fuel...
No, that's not the case. The mixture is controlled by the ECU based on the inputs from the oxygen sensors.

as i did say in my other post tho, too high an octane fuel can be bad for the car - overheating is something i have personally had experience with due to using too high a octane rated fuel..

*gets back in box again*
If your engine overheated, it's not likely that it was due to the fuel you used. If your catalytic converter overheated, it may well be from to high octane fuel.

[cbrmale]

As far as octane goes, I ran my Elantra on 91 RON and it used to ping sometimes. I changed to 95 RON, which is allowable by the handbook, and it doesn't ping anymore. It also runs smoother and a little better. However, I would not run it on 98 RON, as too high octane rating makes the engine run cooler internally, and build up carbon.

I suspect the Elantra engine is a 95 engine with a knock sensor to stop it destroying itself on low octane petrol.

[Seinster]

I never had pinging on 91RON, but personally I always use 95RON as well simply because I get better MPG (L/100km) out of it.
For 1.60 (let's take that to be 1.2L [less than half a gallon]) I get an extra 200km (124miles) per tank (taking the tank as being 40L), it's simple economics to me.

ElantraElite has been running his car on 98RON since he bought it, and has no problems. I just don't see any value in doing that.

I've experimented with many fuels (E10 95RON, E10 98RON, 98RON Unleaded, 95RON Unleaded & 91RON Unleaded) from all companies here (E10 was only from LibertyOil), and now stick only to 95RON Shell fuel.

Experience the difference for yourselves, and reset your ECU anytime you switch grades of octane for a better comparison...I don't understand why, but it worked for me.

[Bnystrom]

Octane ratings are different in the US. Ours are 87, 89 and 91, based on the (r+m)/2 formula.