Interesting fuel....

[freeatlast]

Originally Posted by Draigflag

You don't get it in the US, it's too fancy



Well a third party carried out some tests over 5000 miles and it does give better fuel economy, they would be sued over trades description act if it didn't. I googled it, found the usual marketing nonsense, apparently it has better lubricating properties that give an even coverage over the pistons and more detergents etc etc...

Interesting. Thank you for the information. However I would point out any increase in MPG is not due to an increase in octane. Any increase would come from the same things that increase our MPG here with summer gas verses winter gas.
Summer-grade versus Winter-grade Fuel - Why is summer fuel more expensive than winter fuel? | HowStuffWorks

[freeatlast]

Originally Posted by R.I.D.E.

While there may be "limits" to the range of spark retardation when engine knock is detected, it is not limited to recommended fuel octane. In engines where the compression or other specifics of design absolutely require premium, IE turbocharged ultra high performance engines, they will not "disintegrate" if you use regular fuel, but you will notice significant loss of performance.

If that were the case you would see manufacturers-dealers refusing to honor a warranty if the customer had EVER used regular fuel in the vehicle.

30 years in the auto business, 60k hours of tech work, intimate knowledge of systems and their functions here. From the late 1960s to the end of the twentieth century, when emissions systems went from primitive to fairly sophisticated.

Today, with direct injection, you can have multiple injections, while combustion is occurring, which prevents knock altogether and slows down the combustion event to allow more pressure later in the downward movement of the piston, when the "leverage" of the big end of the connecting rod and crankshaft journal is better for power transmission.

Not as late as 90 degrees after TDC since the pressure levels drop off rapidly by then but closer to the 90 degree point.

Preignition or detonation, called spark knock, is when the mixture ignites before the piston reaches top dead center, the flame front collides with parts of the combustion chamber and then reflects back into itself.

Multiple injections, in a single combustion event, require direct injection into the combustion chamber as well as ultra high injection pressures of 3000+ PSI eliminate any possibility of knocking, as long as everything is working properly.

Thanks for the explanation, but I do understand all that as I used t be a race car driver and did my own work. I also worked in the oilfield industry so I understand about fuel blends and octanes. That being said if there was not a problem with low octane the manufacturer would never spell out a min. I assure you that if knock causes damage the manufacturer will claim you used improper gas and will NOT cover warranty work. The best thing is to stick with what is recommended as lower octane will NOT do you any good.

[JockoT]

Originally Posted by 14Corolla

Advertising ...

It is advertising, but here in the UK an advert has to tell the truth, or the ASA ban it and sanction the company. You can leave stuff out of an advert but you cannot make stuff up.

[R.I.D.E.]

With the newer integration of processing capabilities, every engine since 1995 in the US has the capability to "count" the teeth in the flywheel ring gear. A 1995 Sentra flywheel has 105 teeth. At 700 rpm idle speed that's 105X700 recorded pulses, every minute. This allows the power created by each cylinder to be compared to the others.

That measurement is called active cylinder balance, and it was required by the OBD2 systems that were standardized to allow anyone to properly diagnose engine misfires. If there is good spark and compression then it almost has to be fuel injection quality, either volume or spray pattern.

Good diagnostics are essential to proper, one effort repairs. This was the capabilities 23 years ago. Today I can only imagine the capabilities, performance levels unheard of in the past are routine now. Efficiency and performance are no longer a one or the other choice. Changing cam lift, duration, and even valve activity altogether have meant throttle plates can be wide open and power controlled through valve actuation.

[14Corolla]

I just got my worst summer mileage with this fuel. Actually two reasons.
1) My tire pressure was low. All four tires at 28 pounds. Should be 32. Don't know how it happened? I thought they felt low. I usually don't obsess over tire pressure.
2) When I fueled up. The fuel ran over. I usually let it stop on top. Then run it up at a certain slow speed. Then let it shut itself off a second time. It didn't shut off. Doh! This has always worked good for consistency in the past. ... This one station has some upkeep issues. Think I might try the same brand, another station that is still within my town limits.
So oh well.... Am sure I'll be back up there on the next tank. Live and learn.