87 vs. 89 vs. 91 Octain fuel. My findings....

WTF?

I was referring to chris's gas mileage which seams a bit on the low side. If he wasn't going 68mph - he might see better mpg.

 

Among other things Chris never said his gas mileage was a problem and 68mph was a target speed for consistency on the mileage test loop. So you are making references to points that were not made.

 

Have you been following the posts?

It was MY OPPINION that his gas mileage was a bit low. I'm not the only person who commented on that. Chris explained why.... I understand.

But when he said he's going 68mph - I simply said...."There's your problem! Slow it down and run the tests again!!" Perhaps he'd get even better mileage if he went slower??? I'd personally be curious to see what kind of results he'd get going slower.

Chill out....I think you got lost in the flow of things there a bit. Sorry...but it wasn't meant to be taken all serious-like. Chris already knows I'm a putz. (hehehe)

 

My case in point!

He is not trying to improve his gas mileage. He is simply comparing the different grades on a consistent loop.

 

Hellooooo?? Anybody home?

You're still not telling me anything that I didn't already know.

Isocoee - I'll drink a few for ya..how's that? I just got off work and it's time for bed. Good night!

 

Yes, get a good nights sleep and then think about it.

 

What were you saying? Explain it to me again....

 

We are just exercising our rights to be "One big happy dysfunctional family"

 

....and you're the one who suggested us all have a drink!!

So you're the blame for it all!

 

yup the sh*t in here starts at the top

 

Maybe if Chris ran Vodka in his tank he could get 20mpg on his test loop!

 

Looks like a good attempt at controlling variables. I'd be interested in the same test if it were controlled for weather conditions and more importantly if it were 'double blind;' that is, if the driver did not know what gas was in the tank. It is amazing what we do unconsciously or otherwise when we want certain outcomes. And good scientists are aware that all too often they want certain outcomes even though they know they should try to be objective. That's one of the reasons for double blind studies.

Everything I read from 'reliable' sources refers to the 'octane myth.'

From Suffolk County, NY:

"....The advertising claims for these various grades would have us believe that the higher the octane of the gasoline that you use in your car, the better your car will run...more efficiently, cleaner, and with more "power." These are tempting claims.

....Octane ratings are a measure of a gasoline's ability to resist engine knock. "Knocking" or "pinging" in an engine results from an uneven burning of the fuel-air mixture. If your car is not "knocking," using a higher octane fuel will do absolutely nothing for you but waste your money. The fact is that regular unleaded gasoline, 87 octane, is the recommended fuel for most vehicles. You can determine what fuel is recommended for your vehicle by checking your owner's manual.

If you are using gasoline with an octane rating greater than 87 and your engine is not "knocking," drop down to a lower octane gasoline. If your engine begins to "knock," go back up to the next octane level. Remember, octane is nothing more than a measure of anti-knock quality...use the lowest octane fuel which provides you with knock-free operation.

Another myth is that use of a high octane fuel will improve fuel economy. The fact is that fuel economy is determined by a number of variables, including the energy content of the fuel and the condition of your vehicle, neither one of which have anything to do with the octane level of the fuel. In fact, two fuels of identical octane could have different energy content due to a difference in composition.
...."

From the State of Minnesota's Dept of Commerce:

"• If your engine runs well and does not knock or ping on low octane gasoline, there is no advantage in
switching to higher octane gasoline.
• If your engine knocks or pings, it does not necessarily mean something is wrong with the gasoline. It could
be a problem with the engine’s electronic control systems, ignition timing or exhaust gas recirculation. On a
high mileage engine, a carbon build-up in the cylinders can increase cylinder pressures and cause knock.• Almost all of today’s new cars have fuel-injected engines that need to use gasoline with a detergent additive.
They do not necessarily need high octane gasoline with a detergent additive. Generally, new automobiles
need high octane gasoline only if the manufacturer recommends it.
• Always follow the auto manufacturer’s octane recommendations in your owner’s manual.
Octane Myths
• High octane gasoline improves mileage.
In general, if your car is designed to run on 87 octane gasoline, high octane gasoline will not improve
mileage. If switching to high octane gasoline does improve mileage, you might find that your engine, or its
control systems, need repair.
• High octane gasoline gives quicker starting.
No, it doesn’t.
• High octane gasoline increases power.
If your car is designed to run on 87 octane gasoline, you shouldn’t notice any more power on high octane
gasoline. Again, if it does make a noticeable difference, your engine, or the engine’s electronic control
systems, may need repair.
• High octane gasoline has been refined more – it is just a better product.
Additional refining steps are used to increase the octane; however, these additional steps do not necessarily
make the gasoline a “better” product for all engines. They just yield a different blend of hydrocarbons that
burn more slowly. The additional steps also increase the price."

 

Was the different grades of gas used all with some and the same amount of ethanol?

In my area 87 & 89 octane contain up to 10% ethanol, however 91 octane does not have ethanol. Ethanol has a lower energy content, 70% the amount of energy as regular gasoline.

 

I'm a believer in 91! Shoot me...

 

yeah me too. 91 naysayers don't get that 91 burns better than 87-and if ya don't get knock with 87 it's due to the computer retarding your timing to null it, resulting in less power and more throttle input. The increased 91 price per gallon is justified and negated via better burning. I have been running 91 in my truck its whole life. Not one single ping or knock out of that motor.