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Regarding damage due to using 87 octane gas and Acura agreeing there would be none... I have no idea how you gained that information other than by twisting the meaning of words and contacting a level 1 clerk with bare minimum knowledge of the Acura powertrain.
-Use of 87 octane fuel does not seem to lead to engine damage. (based on anecdotal evidence)
Personal attacks and accusations will not be tolerated. I will be reporting anyone who does so. If you have no data to post, do not post.
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and the 2006 owner's manual)
Use of 87 octane fuel does not change engine characteristics below 50% load (based on measured data).
Above 50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
Ugh, I said I was out but I just realized there is an enormous fallacy with the data you're using to justify your conclusions.
This is your original post.
Originally Posted by RustyLogic
FYI,
Besides "pure" 93 (several fill ups) and "pure" 87 (2 fillups), I tried a mix, which I estimated to be around 91.4 octane. Here is the result. The differences between 91.4 and 87 are less apparent than with 93. So additional octane above 91 actually improves performance over 91. Therefore, the dropoff in the timing curve is the knock sensor retardation.
A few conclusions we can make right now to this thread:
1) Third generation TL is in the "91 recommended" category, not the "91 required".
2) The knock sensor is used to retard timing under all octane levels. The octane level shifts at what load/IAT the engine begins to rely on the knock sensor. This means even when you run 93, the knock sensor will "detect knock" at minuscule levels before they are harmful, and adjust timing.
3) Only use of octane below 87 may lead to engine damage. 87 or above, and below 91, leads to decreased performance and possible ping/knock with a combination of high temperatures and high load.
Everyone is free to use whatever fuel they feel most comfortable using. But let the above information be a guide.
The fallacy is in the presentation of the data. Unfortunately, this data set doesn't tell us anything. The reason that it doesn't tell us anything is that it does not specify the engine RPM at which the data was collected. The reason that the engine RPM is relevant here is that 50% load would have a different ignition timing advance at 1500 RPM when compared to 5000 RPM. This data should be presented in three dimensions with RPM on the z-axis for it to hold validity. It would be only then that we can draw a conclusion on the effects of octane on ignition timing. I could create this graph by blipping the throttle in 6th gear at 2000 RPM and it would produce different results than in a lower gear at the same speed with the same technique. Basically I can fabricate this data and make 87 look just as good as 93, or make 87 look like it doesn't belong anywhere near this car. Unfortunately, not willing to put 87 in my car.
The data was generated making the exact same drives in the same driving styles as much as possible. The variation in RPM is demonstrated as the spread of each of the curves. In one of the posts on an earlier page, I calculated the differences controlling for RPM for 87 and 93.
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and the 2006 owner's manual)
Use of 87 octane fuel does not change engine characteristics below 50% load (based on measured data).
Above 50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
Last edited by RustyLogic; 02-11-2015 at 04:39 PM.
Keeping the drives and driving styles the same is definitely important, but unfortunately it doesn't have an effect on the presentation of this data. I can't disagree that these data points exist at different RPM levels. You were driving the car, after all. They must have been changing. But, we don't know at what RPM the data points are located. Seeing this data on a 3D graph is the only way to tell the full story with scientific accuracy.
Let me phrase it in a different way. The ignition retarding is the output. What you're saying is that the retarding is a function of octane and engine load. What I'm saying is that it's a function of octane, engine load, and engine RPM.
As posted earlier, ignition timing changes between 93 and 87, averaged across all RPM ranges, equally weighted.
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and the 2006 owner's manual)
Use of 87 octane fuel does not change engine characteristics below 50% load (based on measured data).
Above 50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
Personal attacks and accusations will not be tolerated. I will be reporting anyone who does so. If you have no data to post, do not post.
Personal attack and accusation? If I wanted to attack you personally, I would have kept it to 1 sentence believe me.
Regarding accusation of twisting the meaning of the words in the manual, this goes hand in hand with your blatant ignoring of the rest of my post. You promote the data and discussion that supports your motive, but dismiss everything else. I was under the impression you were open to intelligent discussion, this was a mistake.
I'm out. Can't deal with that sort of close minded attitude.
As posted earlier, ignition timing changes between 93 and 87, averaged across all RPM ranges, equally weighted.
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and the 2006 owner's manual)
Use of 87 octane fuel does not change engine characteristics below 50% load (based on measured data).
Above 50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
Dude. This is not valid. You can't just say that it's averaged across the entire RPM range. Firstly, you didn't even mention an assumed statistical distribution of the range. Second, we have no idea what weight each of the RPM points carries. And thirdly, your graph doesn't even have axis labels lol.
This graph can be completely manipulated by collecting the data in different RPM ranges. And if data can be manipulated or fabricated, it's completely invalid.
Edit:
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 87 octane fuel may not lead to engine damage. (based on input from the manufacturer and the 2006 owner's manual)
Use of 87 octane fuel does not change engine characteristics below 50% load (based on measured data). This conclusion is completely invalid. Engine characteristics will very likely be changed even below 50% load at higher RPMs.
Above 50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer). There may also be a loss of power below 50% load at a higher RPM range.
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected) You're calling this a conclusion while simultaneously stating that the data is incomplete. I'm sorry for being rude, but this is a slap in the face to science.
Last edited by Vlad_Type_S; 02-11-2015 at 05:12 PM.
I'm going to fix your thread signature, because those clearly aren't the conclusions of the majority in this thread.
Originally Posted by RustyLogic
SUMMARY OF NFN, RUSTY, AND A FEW OTHERS CURRENT CONCLUSIONS:
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and the 2006 owner's manual)
Use of 87 octane fuel does not change engine characteristics below 50% load (based on measured data).
Above 50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
Lower Octane found to be leading cause of ED in OP.
I don't understand the debate, nor the need for 9 pages. Acura says put 91 or above in...do it. If 87 was the same thing, they wouldn't even bother labeling octanes...it would just be "put some of this here nasty smelling shit in that there tank of yourn".
Personal attacks and accusations will not be tolerated. I will be reporting anyone who does so. If you have no data to post, do not post.
Do you think no mods come into this thread as it is? Also, you do not set the rules for this thread. Please do not tell people who can or cannot post, as you do not have any relevant data either- as pointed out, your graphs, although pretty, do not form any real data; they are erroneous at best. It doesn't help that others who side with you like to spread misinformation which is an even worse offence to the community.
You are trying to take a complex machine that has been refined by countless engineers and designers over many many years into a simple device, which simply is not possible. We have no idea what the numerous variables are doing at any given time, nor do we have the ability to recreate identical scenarios each and every time. The scan gauge that some possess is only a fraction of the puzzle.
I know you will argue this, but please understand, without investing the proper money to do so, we cannot simplify this into an easily controlled situation. Even your graphs show data points all over the map. We have come to understand how you and others feel about different grades of gasoline and that's all good. If you want to keep debating it, take it to private messaging so that you do not influence others with your beliefs, which whole heartedly are ill advised by the manufacturer themselves, and splitting hairs because of certain words used in a two sentence response to an inquiry is not solid justification to continue on.
I don't want to belittle OP. He's actually trying to use science to answer a question that he has and I respect that a lot in a person. But scientific findings have to be presented very carefully. If you remove the insults and attacks from this thread, what you basically have is a peer review of your scientific findings (standard process for any publication). If you really want to pursue this, I suggest scrapping your data and starting over while also including RPM on a 3D plot. Upload the data too, in addition to the plot. And when you switch from 93 to 87, be sure to run the engine until it dies to ensure that the octane is actually totally 87.
Another useful 3D plot would be engine load as a function of engine RPM and throttle position. So if you're using a scanner, collect that data! I'd expect some kind of very specific conclusion, such as "the performance difference between 87 and 93 is negligible under the following load and engine rpm conditions."
Last edited by Vlad_Type_S; 02-11-2015 at 06:05 PM.
Why make an open debate if you're going to go run for the moderators to start handing out vacations? Just because we don't agree with you?
Yet you make these petty rules and NFNSQUAD can clearly break them, but you won't say anything about that because he's your buddy right?
You want respect, you should have earned it. When you didn't reply to my PM and say thank you for providing the information you requested, you lost my respect and so did NFN for insulting my years of education based on his personal judgement on the automotive industry. I respect your study and what you have contributed to this thread, more than I can say about NFNSQUAD. Hell even Acura-OC had decent points, and he's another die hard 87 octane fan.
Food for thought, if you can't make a thread and expect others to not agree with you, then don't bother making a thread.
Last edited by 04WDPSeDaN; 02-11-2015 at 07:58 PM.
I don't want to belittle OP. He's actually trying to use science to answer a question that he has and I respect that a lot in a person. But scientific findings have to be presented very carefully. If you remove the insults and attacks from this thread, what you basically have is a peer review of your scientific findings (standard process for any publication). If you really want to pursue this, I suggest scrapping your data and starting over while also including RPM on a 3D plot. Upload the data too, in addition to the plot. And when you switch from 93 to 87, be sure to run the engine until it dies to ensure that the octane is actually totally 87.
Another useful 3D plot would be engine load as a function of engine RPM and throttle position. So if you're using a scanner, collect that data! I'd expect some kind of very specific conclusion, such as "the performance difference between 87 and 93 is negligible under the following load and engine rpm conditions."
This is what Vlad wants, but with the data you collected These are the IGN profiles (high and low cam) of the basemap for a J32A3.
There are too many uncontrollable variables that will undoubtedly skew the results. This needs to be done properly, in a controlled environment, with a shit ton of gauges and data recorders.
Temperature, wind speeds, wind direction, driver (we know the ecu "learns" our driving habits- can we be certain they were identical in all cases? How much time went on under each?), actual remaining fuel in the tank (need several several tanks of each for accurate results. 2 is not enough. Again we know the ecu likes to fuck around and change on us. Need consistency), roads driven, how much stop and go was there, etc, etc, etc.
Then we need the appropriate sensors spitting out appropriate data, not inferring what the ecu is putting out to the scan gauge. The ecu can be skewing the data trying to be inferred anyway, and we wouldn't even know it.
If someone is interested in doing such a study in a peer reviewed fashion, I'm all for it and I'll shut the hell up. It might be beneficial to find some sources for funding because it won't be cheap (hey, even 2k out of pocket for this is expensive). As of right now, at best, this is being done in a hocus pocus type fashion.
Measured timing for every sampled RPM/load point. For each RPM/load, averaged that RPM/load if it was experienced more than once. Then averaged over RPMs for a given load. The X-axis is, of course, load. The Y-axis is change in timing (degrees). If you would like to see a 3D plot, please collect data as well and post it. Otherwise do not post.
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and the 2006 owner's manual)
Use of 87 octane fuel does not change engine characteristics below 50% load (based on measured data).
Above 50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
Data sampled at 50-60F IAT:
Last edited by RustyLogic; 02-12-2015 at 04:40 AM.
Here, I will even start summarizing sources for all these statements. If you would like to see a particular experiment done, I am not taking requests, but I encourage you to do the experiment yourself and post the data. If you have no data to post, do not post.
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 91 octane for the third generation TL is "recommended" but not "required." (manufacturer input and 2006 owners manual)
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and clearly stated in the 2006 owner's manual*)
Use of 87 octane fuel does not change engine characteristics below ~50% load (based on measured data from multiple users).
Above ~50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
MYTH: Using regular gas in a car designed for premium will definitely damage the engine.
We don't believe that any modern engine that claims to require premium will be damaged by using regular unleaded judiciously. Neither do any of the sources we've checked with - including the American Petroleum Institute, the American Engine Rebuilders Association - even a chemist (who would rather go unnamed) at a major gasoline company.
Data sampled at 50-60F IAT:
Last edited by RustyLogic; 02-12-2015 at 05:14 AM.
[*] Use of 91 octane for the third generation TL is "recommended" but not "required." (manufacturer input and 2006 owners manual)[*] Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and clearly stated in the 2006 owner's manual*)[*] Use of 87 octane fuel does not change engine characteristics below ~50% load (based on measured data from multiple users).[*] Above ~50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data and manufacturer).[*] The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data).[*] 87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)[/LIST]
Why do you continue to state that the owner's manual clearly states that 91 octane is recommended when the manual states the opposite?
2006 Owner's manual:
Fuel Recommendation
Your vehicle is designed to operate on premium unleaded gasoline with a
pump octane of 91 or higher. Use of a lower octane gasoline can cause
occasional metallic knocking noises in the engine and will result in
decreased engine performance. Use of a gasoline with a pump octane less
than 87 can lead to engine damage. We recommend quality gasolines
containing detergent additives that help prevent fuel system and engine
deposits.
My interpretation of the above is that the engine is designed to run on 91 octane, period. Also, there is nothing in the manual stating that engine damage won't result in using a lower grade fuel.
If a Type S (same C.R.) the manual (same heading) states 91 octane or higher to be used and if unavailable, 87 octane or higher can be used temporarily.
With the above info we can, at least I can, conclude that 91 octane is the fuel requirement.
Many people will run regular grade in cars that require premium and encounter no driveability problems as long as they drive cautiously.
Fuel Recommendation
Your vehicle is designed to operate on premium unleaded gasoline with a
pump octane of 91 or higher. Use of a lower octane gasoline can cause
occasional metallic knocking noises in the engine and will result in
decreased engine performance. Use of a gasoline with a pump octane less
than 87 can lead to engine damage.
Many people will run regular grade in cars that require premium and encounter no driveability problems as long as they drive cautiously.
Yes, it was designed to provide additional power with 91. But it clearly states 91 is "recommended". It does not say "required". And it also only states that octane levels below 87 "can" lead to engine damage.
There's nothing wrong with using 91 or 93 to attain maximum power output of the engine. There is also nothing wrong with using 87 octane if you don't need that full power. But all the manufacturer statements and data we've collected show that power/cost is the only tradeoff. Nobody has shown any data demonstrating that 87 caused engine damage or increased carbon buildup.
CURRENT THREAD CONCLUSIONS SUMMARY:
Use of 91 octane for the third generation TL is "recommended" but not "required." (manufacturer input and 2006 owners manual)
Use of 87 octane fuel does not lead to engine damage. (based on input from the manufacturer and clearly stated in the 2006 owner's manual*)
Use of 87 octane fuel does not change engine characteristics below ~50% load (based on measured data at 50-60F IAT from multiple users).
Above ~50% load, there is a loss of power using 87 octane compared to 91 or 93 octane (based on data at 50-60F IAT and manufacturer).
The knock sensor is used to retard timing across all octane levels, depending on load and octane. (based on experimental data at 50-60F IAT).
87 octane fuel costs 20% less than 93 in some areas of the nation. Current measurements of changes in MPG are negligible, if they occur at all. (partial data, still being collected)
MYTH: Using regular gas in a car designed for premium will definitely damage the engine.
We don't believe that any modern engine that claims to require premium will be damaged by using regular unleaded judiciously. Neither do any of the sources we've checked with - including the American Petroleum Institute, the American Engine Rebuilders Association - even a chemist (who would rather go unnamed) at a major gasoline company.
Timing data collected at 50-60F IAT:
Last edited by RustyLogic; 02-12-2015 at 07:02 AM.
Yes, it was designed to provide additional power with 91. But it clearly states 91 is "recommended". It does not say "required". And it also only states that octane levels below 87 "can" lead to engine damage.
The title is fuel recommendation, and the that fuel is 91. Nothing hard about the conclusion, but I believe you're interpreting the fuel recommendation title as just that, recommended but not required.
If that were the case the Type S, as I stated previously, has the same heading and nomenclature, but also notes that anything less than 91 to be used only as a temporary measure, so must say, that negates your theory of recommended as 91 is required.
Also, to repeat, the fuel door states premium unleaded fuel only, a far cry from recommended.
Similar to the new Cadillac CTS-V Fuel recommendation
If the vehicle has the 6.2L V8 engine (VIN Code P), use premium
unleaded gasoline with a posted octane rating of 91 or higher. For
best performance, use premium unleaded gasoline with a posted
octane rating of 93. In an emergency, you can use regular
unleaded gasoline with an octane rating of 87 or higher. If 87 octane
fuel is used, do not perform any aggressive driving maneuvers such
as wide open throttle applications. You might also hear audible spark
knock during acceleration. Refill the tank with premium fuel as soon as
possible to avoid damaging the engine.
Note the title Fuel Recommendation. With your interpretation this would
would indicate the CTS-V could be operated on 87 without a problem.
Far from true.
Actually the 2015 Corvette Stingray contains the same title, Fuel Recommendation......................
Need I say anymore?
Originally Posted by Turbonut
Note the title Fuel Recommendation. With your interpretation this would
would indicate the CTS-V could be operated on 87 without a problem.
Far from true.
Thanks Turbonut.
OP. I have clearly explained why this states "recommendation" instead of "requirement". I cited an industry standard publication. It's not just Acura, it's not just automotive, it's literally everywhere that engineers write documents.
Why did you ignore that and continue to latch onto your own interpretation when I'm pretty much spoon feeding you the way that these documents are created and the language that's used? The use of the words shall, should, required, recommended, can't, and won't are all VERY carefully controlled with strict definitions.
Originally Posted by RustyLogic
Measured timing for every sampled RPM/load point. For each RPM/load, averaged that RPM/load if it was experienced more than once.
This is extremely unclear, but it's the only response in anything you've said so far that tries to address what you've been challenged with. What data did you collect? I assume that you have a file? If you're saying that you collected timing, RPM, and load, then upload the file here and I'll make the damn 3D plot.
But it actually sounds like you think RPM and load are the same thing and that they can be used interchangeably. And this is simply wrong.
Originally Posted by RustyLogic
If you have no data to post, do not post.
This is absurd. I will post. Read this: http://en.wikipedia.org/wiki/Peer_review
Then realize that your data is subject to scrutiny and that you should back up your findings when you are challenged with science. All you've done is ignore all of the rational ways in which your data has been challenged. Stop ignoring these challenges and address them directly. Your listed conclusions are invalid until you address the challenges to your data, so stop posting them because it's highly unfair and misleading to readers. I respected you in my last post for your seeming desire to remain somewhat methodical and scientific. That respect is now diminished for I'm dumbfounded how you tell us to post data or GTFO, yet you quote a car talk myth in the same post.
And your quote isn't even relevant. "Using regular gas in a car designed for premium will definitely damage the engine."
We've already concluded that it will not "definitely damage the engine" so this doesn't add anything to the discussion.
(The Honda Tech link you posted isn't valid. You might also want to check your links before posting them, kind of helps maintain credibility.)
Vlad, you are 100% right- engineers don't like using exact phrasing as it can cause legal issues for them. If someone did put 91 in and the car kept running, like you said, it isn't technically required then because the car will run on other grades. That doesn't mean it's good either though.
Also, acura won't say "OMFG IF YOU PUT REGZ IN, YOUR ENGINEZ WILL BLOW", because if it doesn't, they are again spreading misinformation.
Chalk this up as a loss, Rusty, NFN, and whoever else is in this boat. Keep doing as you please, but you guys don't have much of a leg to stand on in this argument.
Although, I'm quite curious, when a guy opens his gas cap and sees "Premium unleaded fuel required", what makes him think "hmmmm... I wonder what 87 will do..." And then afterwards goes "eureka! My engine didn't explode! Im a genius!!"
Vlad, you are 100% right- engineers don't like using exact phrasing as it can cause legal issues for them. If someone did put 91 in and the car kept running, like you said, it isn't technically required then because the car will run on other grades. That doesn't mean it's good either though.
Not only do we not like using this kind of phrasing (we avoid being wrong as much as possible ), but it's absolutely required (not recommended) by regulatory bodies that we abide to the published standards if we want to bring products into the marketplace. This isn't an opinion and isn't up for debate. This is the way industry operates.
02-11-2015, 03:58 PM
to death!
These are the IGN profiles (high and low cam) of the basemap for a J32A3.
), but it's absolutely required (not recommended) by regulatory bodies that we abide to the published standards if we want to bring products into the marketplace. This isn't an opinion and isn't up for debate. This is the way industry operates.
