Read this and then you will understand that even premium is too low under some conditions. http://www.crcao.com/reports/recents...l%20Report.pdf

 

It's an interesting paper, but its conclusion is that higher octane would facilitate car manufactures increasing compression ratios in future designs, resulting in better performance. But that changes in engine technology may make higher octane unnecessary to achieve the same results.

It does not conclude that existing cars designed for regular fuel would benefit from higher octane.

See page 60 section 5.3 item 1 and item 7.

 

Nice try Steve that is a DI engine which is a Compression spark assist ignition motor just like a diesel minus the spark plug. Which if you look into that they have there own problems with fuel quality. Look at page 53 section B Number 1 and that is for a 10 to 1 compression motor. Also look at section A number 2. Keep in mind the retard needed for a 10.5 motor to operate on 91 ron fuel.

 

Page 53 section B number 1 notes the octane requirements for test engines of various bores noting the smaller bore engines have a lower requirement. What was your point?

The paper concludes that Direct Injection (DI) might be used to mitigate the needs of future higher compression engines (11 or higher), but that other technologies (including smaller bores) would also be used negating the need for the availability of higher octane fuel.

It also lends insight into how Fits with a 10.4 compression ratio and bore of 73mm are designed to run on regular fuel, where a 40 year old design could not.

No where does it state that existing designs will perform better with higher octane fuels, where it's not already required or recommended.

Try again.

 

Read what you want but your wrong. Yes it can work on regular but that is only the lowest octane and does not include fuel quality differences and Octane requirement Increase. Phase separation in E10 93 octane will still have an octane the motor can run on, but not if 87 separated it would be too low causing a whole list of problems most of which have been hammered on this forum. You cant even go to Honda because they said 87 or higher. I will say that a mix of premium and regular/midgrade would be suffice on most operating conditions especially in winter for cost control and still get better mpg than just on regular.

 

Sure you can. If there was a benefit it would have stated 89 or 91 AKI "recommended."

Honda/Acura are not above recommending or requiring premium fuel in their cars where there's some reason to. They aren't playing marketing or word games.

Here's the page for their 2.4L

Check the pop-up for footnote 20!


Compare this with the Fit's.

If there was something published saying the Fit or any car that does not recommend or require higher octane than 87 could benefit from higher octane than regular I think you would have linked to it by now.

Your cite illustrates how car manufacturers are designing engines to run on regular gas now and in the future while increasing performance. Thanks.

 

That snap shot of a datalog showing knock counts even in favorable conditions I posted from a GD3 was with 93.

Let the windbag further discredit himself, it will only provide me with some much needed schadenfreude.

 

I have made the mistake of actually giving an opinion on here before, but the whole point of this thread was to talk about GAS MILLAGE not the fact that running 93 or 87 causes more or less knock. This has just become a S-show of people being know it alls. So has any one proven that using 93 in our cars. specifically gd3's that it makes a difference in fuel millage..and I am not talking about .1 MPG.

 

You've already made up your mind, whats there to talk about? By the way your "opinion" is not going to be given the same consideration as fact. So.. go cry about that some more.

Had you, I don't know, read the other posts around yours there are testimonies to achieving better fuel economy on premium. It's not universal, because the world is a complex place. I imagine this can be frightening for some, who don't like their biases being challenged.

Fun fact: Spark Angle and Air Fuel Ratios, both of which are directly and negatively impacted by knock retard, directly affect fuel economy.

I'd recommend you go research, but you seem the type like Steve who doesn't understand the basics enough to do anything but push your own opinion. Which as we've discussed isn't worth shit.

 

I am not "crying" about it. I was asking a question. I get that you have data showing knock with up to 93, and that some people have shown that running 93 yields slightly..very slightly better fuel mileage. Get off your high horse. You are making something so simple into something so much more just to prove you know more than some one else. confuchsia says "go piss up a rope"

 

I have data showing more than just knock, and so do many others. On many different platforms, new and old.

You want to trivialize something complex that you don't understand to feel better it sounds like.

There is a laundry list of reasons to run premium, but no one is making you do it.

You can get away with 87 and nobody is stopping you or telling you do to otherwise, but you still feel the need to justify your choice for reasons other than preference. They are just explaining why it is a choice some of us have made based on data and understanding.

The justifications you want to make, going back to your haggard BBC example.. don't exist. Because for the same reasons it was beneficial in the BBC it is beneficial in the L15.

Just do it as you please, don't need to try and prove to us its the "right choice" because there is no "right choice."

Don't act like a stubborn f*ckstick about it.

 

A trivial question does not need a complex answer. Does 93 get better MPG, yes but .2 mpg see there that is a simple answer. Not "well here is a mass amount of data showing this this and this" but in the end the answer is still .2 mpg. Its fine if you need to validate your existence by over answering something to show how smart you are.

 

Translation:

 

Just buying a few tanks of the good stuff and using more throttle and revs a time or two when you drive and making your own determination if your mileage and (or) performance has improved isn't difficult or costly... Your car's ECU will need to adjust to the change of fuel so you won't feel or see a mileage improvement immediately... Unless you try it you have no idea whether there is a difference or not... It saddens me to see so many people that have no confidence in their ability to base an opinion based on their own personal experiences instead of seeking out information from others that think the same way and then slander those that do.

 

I don't know if that was directed at me. This all started because I made the mistake of not agreeing with diomandmonster about something. I had stated driving habits effect fuel millage more than fuel grade. Which last time I checked is fact.

 

Except this is the full text of what you said. And here is the part we are disagreeing with:

Then you went full retard from there on out.

After that it was the Big Block Chevy allegory, which was debunked. Then you tried to go from the top again:

No one is disagreeing that a large component of fuel economy comes down to operator habits.. not a single person in here. So that's like coming in here and saying "sofia vergara is hot and I knocked her up."

It's almost universally understood that the former is true

So when we call you out on the latter, and you come back to the "she's hot" portion like that is the contentious bit and central tenet of your statements intent we're gonna have to call bullshit.

You came in here to make your assertion on fuel grade and how it relates to the fuel economy discussion. It was your first sentence for fucks sake, don't be coy.

That you shared a bit of "sky is blue" wisdom along side is not what were taking issue with.

Originally it read like this:


But its pretty clear now that you are one of the true believer types..

And now we're cycling back and forth on the "its just my opinion aren't we just here to talk bros??" style of reasoning like a Rush Limbaugh or Glenn Back trying to defend the indefensible from a position of pandered ignorance.

The infamous "I'm sorry you're offended, I'm just a comedian its a joke can't you take a joke" form of escape route for a moron trying to get his 2 cents in. It's disingenuous and you knew you stepped in some shit, but you can't back out now for who knows what reason.

When I don't know what I'm talking about, i try not to interject. Which is why you'll only see me in threads where I have some background typically. When I am wrong, and called on it.. I own it like a man and accept it. Sometimes thats embarrassing but.. It happens, grow up.

When a wise man is confronted with evidence that challenges his hypotheses.. he changes them and tries again.

 

No sir it wasn't directed at you... I tend to agree with you about driving habits effecting fuel mileage... That is why I suggest that a person use more throttle and revs on occasion when seeing whether they have a mileage gain with higher octane fuel... A few of us here get itchy trigger fingers because we share our observations only to have a troll that keeps contradicting his sources of searched out information and demanding that we do the same... This has been an ongoing thing for awhile... Deciding whether to use a product or not to and being attacked all of the time because of another's ego issues will tend to have an effect on a person.. I'm afraid that you may have been in the line of fire that was directed elsewhere... I do strongly feel that a person has to see for themselves whether they benefit from something or not... I'm old school and have the need to see for myself whether or not something is going to work.

 

you should heed your own advice there. I am not backing down and I am not wrong in saying that by putting 87 in as compared to 93 is does almost nothing as per MPG which this thread is about. If I was wrong I would admit it. you nor your data show that there is any significant gains when using 93. Saying that it does nothing helpful in a thread about MPG it would imply I am talking about MPG. I am not making a cop out. I am more than happy to admit when I am in the wrong, as I am an adult. If we were talking about performance effects I would agree with you but this post was about MPG's. I get that you actually know what you are talking about with fuel maps and knock and all that jazz. But honestly your such an ass hat I could really give a flying F.

 

Indeed sir.

 

Here's some recent testimony towards what we are trying to get through your thick head. You could actually have searched any of the others sharing their reports.. but you are in too deep now.

Also, fuel efficiency is a function of performance as well. Trying to make the most power out of a given displacement with the least fuel is the whole point.

The leaner you can run under full load.. the more heat/pressure you can generate.

Lean, for the uninitiated refers to a greater oxygen:fuel ratio. It also produces lower EGT because there is less fuel burning on the way out the exhaust valve.

If I can run the same timing at the same CR at 13.0:1AFR vs 10.5:1 I would do it. It will burn faster and hotter in cylinder, producing more torque.

What I love is that you are saying "I know you know what you are talking about, but I don't like the way you say it.. so I am going to continue resisting to learn"