How many have good fuel mileage data and have tried using high octane (think it's 93) at the pump. How was the mileage?

Ralph

 

Worse than using regular which is what the engine is designed to burn.

 

I know that's what it is designed to burn. I want to know if anyone has tried high octane and has good mpg records on it vs. regular.

 

My wife put Premium in our Mazda3 and it got worse mileage, as it should; premium fuel has slightly less power per unit compared to lower octane fuels.

 

"Premium" fuel does NOT, NOT, NOT produce better gas mileage. It prevents pre-ignition in high compression engines. It also lets gas companies make money off people who think it gives better mileage.

 

Ummm, no, not quite. Premium fuel has zero ability to prevent pre-ignition (i.e. auto-ignition of the air/fuel mixture prior to the spark event); if an engine is so inclined it will suffer pre-ignition and self destruct in a matter of seconds, regardless of what type of fuel is used. That said, Premium fuel is in fact instrumental in preventing detonation (i.e. spontaneous combustion of small pockets of end gas on remote locations in the combustion chamber).

 

Premium fuel could allow the engine's ignition system to be auto advanced some more. This could possibly produce better fuel mileage.

I'm looking for anyone with good records who've done it. There are good scientific reasons for trying it.

Ralph

 

I have to disagree; advancing the timing, if the engine control is so programmed, will not amount to much, if any improvement in fuel economy. Why? Because when in high vacuum mode (i.e. high fuel economy mode), the ignition timing is typically advanced as far as possible already.

Long story short, premium fuel contains slightly fewer calories per unit than regular fuel, unless an engine is designed to rely in premium, using premium will reduce fuel economy. Fact of life.

 

Has anyone used premium fuel in their Skyactiv Mazda? I don't want arguments. I want data.

Ralph

 

Guess you missed my second post in this thread.