How many years have we been explaining this to people here Scratch&Dent????

 

Except for one huge difference, outside countries use different octane ratings, some use RON some use MON. We in the USA use R+M /2 method which is rated much lower then MON since its averaged out with RON.

 

Mini Odyssey: I said that, in Europe the lowest is 95= 91 for USA.

 

Fair trade considering they pay more then twice what we pay for the same gas. Their cheap gas is what our race gas costs.

 

An ad from QT a couple years back. They've since stopped this marketing campaign as it was bad for business:





Dream on that your little econo-boxes will wake up their unrealized potential by adding a few bucks of anti-knock compound to your tanks.

And if you don't think Euros are susceptible to marketing when they're paying $10/gal guess again...

Hi DSM!

And just for fun, here's the C&D article DSM referred to.

Regular or Premium

 

Honda engines are high output and after reading my books at the doctors today I have a better explanation. Its been a while since I read them and got my prospective back on track. Regular is the lowest octane the engine can work on and the parameters that it operates efficiently is only a few if at all. The engine will operate in between 11 and 14 air fuel and produce the same power but its up to you on what side of the curve you want to be on. 14 being better fuel mpg and 11 being the richest it will work. 13 is prime power. So the leaner you run from 11 the more power you will have until you go back down the other side. There are many islands of efficiency your ecu will tune too and with better fuel it will operate in the more efficient islands which means better fuel economy. Before winter in my car it was around 90 octane that I hit 44 mpg and then the cold which the ecu then adds a lot more fuel and will operate richer till warmed up plus less btus in the fuel too. I am still getting 35 mpg with lots of idling and in 0 degree weather driving the same routes.

Europe pays most of their taxes in fuel and don't worry in a few months we will be paying them too.

 

I been fueling up on and off 91 to 87 and frankly i been getting mixed bag results in mpg, it doesn't seem to make much of a impact as i had thought. I still avg about the same. Keeping a keen eye on the tire air pressure had more of a result than the type of gas i been using.... i might go with my old habits of using higher octane 91 in hotter weather summer and using 87 in the colder winters.

 

We have 93 octane here still so I am able to alternate from mid grade to premium in the winter. The problem your having is the ecu wont advance the timing just because you added premium. It takes a while and you have to tell the ecu by doing a few highway runs while doing WOT on the entrance ramps. It will see no knock and start adjusting the timing and fuel trims.

 

The thing cycles back to the most efficient tune in milliseconds, until it detects knock again.

The standard response by the church of premium fuel apologists when new acolytes question the faith is "your car must learn to use the new fuel."

Think about it. There are variations tank to tank using the same grade fuel depending on where and when it's purchased. Would any car manufacturer design the car to run at less than peak efficiency for a long period of time?

 

Its no BS Steve. Go invest in a gauge and see for your self until flash-pro comes out for your car. MBT is actually a narrow operation band compared to regular because when your burning more fuel more time is needed. The ecu wont go to place it was never been so it will take time. "The K.Control is dynamically adjusted at a fairly slow rate while driving". Knock control tables

 

See for myself the car is actively adjusting spark advance and fuel trim several times a second? I don't doubt this.

 

You would also see from running regular to premium it would take time for the timing to adjust. It would start but slowly going back to max timing for regular before going forward. That means at first you would not see a immediate response to premium and would think it there is no advantage. Going WOT just helps it happen faster.

 

I think the question is whether premium will increase MPG. A scangauge isn't required for this. If that's all you got, I'll stick to regular in my Fit.

 

. We all have the ability to read our owners manuals and we also have the right to do what we choose to with our own property without being hassled by a troll... When a person is willing to share knowledge based on experience it isn't necessarily advising another person to do the same... If I choose to do something and I mess up I'll let others know, if there isn't any problem caused by what I have chosen to do I'll say so Why should I or anyone else not pass on to others what their experiences were without being trolled by someone that determines what sources are relevant and which aren't based on who he has chosen that day to troll.... Once again STEVE. The owners manual clearly states that 87 octane fuel is the minimum octane grade to be used... Those of us that can comprehend English do not see that as being a recommended for use in our cars but the absolute sorriest fuel that is safe to use... Those of us with the proper gauges to monitor how the ignition timing responds to fuels with different levels of octane... Most of us that do that also do all of the work on our cars and drive the hell out of them with no negative repercussions ... If we screw up we let others know so they won't do the same... That is how we benefit the forums we are on... Your ass would be so gone on many other forums... I'm on one forum where you have to agree to follow the rules to not be a pain in the ass or face litigation. It would be nice if there were rules like that here but I guess that wouldn't be as lucrative to the lawyers as a forum for luxury cars would be.

 

Those of us that have cars whose manuals state 91 octane is recommended and required also have an appreciation for language and nuance. My hat's off to you for your use of it.

 

91 or Higher is what it says. It also says the timing is consistently being adjusted so why wouldn't it adjust for higher octane. They are required for the engine to be able to use regular and I agree that its the lowest octane you can use but it also doesn't account for ORI and fuel separation from the so called green fuel they call regular.

 

87 or higher...

It adjusts for knock, and that's it. No magic. That premium has a higher AKI than regular, and can be noticed on the Fit's spark advance and trims is evidence the car is working as designed and the retailer is selling you something different for the price, not that the Fit gets better MPG or makes more power using premium.

Really It'd be great if for $3.00 a tank we could increase our cars' MPG and power output 10%. Car manufacturers would flock to this discovery. Every car mag in the world would be shouting accolades for high octane in economy cars. Show me one that claims any performance improvement using premium where it's neither recommended nor required.

Here, I'll help: google premium or regular gas.

 

Screw you Steve... You show me proof based on your own experience that proves that there isn't an increase in power and fuel mileage... I say there is an increase in both based on my own experience.... I was making my living in my own repair shop building high performance engines and doing repairs over 40 years ago... What makes you think that you know more than I do because you read something somewhere.... You don't actually know a damned thing, you just read something you think is right because that is what you choose to believe...

 

I meant 87 but I have 91 on the brain because that is MBT. First they cant make any car just run on regular and since 91 is in the middle of the octane its designed to run on that is what is required. The fuel curve also goes from 11 to 14.7 air fuel that the engine is designed to operate on. Now draw 2 points on one line 11 on the left and 14.7 on the right with 13.2 in the middle The 11 and 14.7 produces the same power but at 13.2 power is up about 5 percent. Now what side of that curve do you want your engine to operate on? That is about 33 percent difference producing the same power with the opportunity of 33 percent in mpg. On average I see 10 to 15 percent increase in mpg because of other variables.

 

My own experience is worth little. I have neither the resources nor money to execute a meaningful experiment. I'll go on published results of others.

Find me something to read that supports your view, and we can discuss it. Till then you're just blowing smoke.