So yesterday I"m at the gas station and their out of 87 & 89 octane. The station offers me 93 for the 87 price. Over the winter I"ve been averaging about 42.5 to 43.5 mpg, I drive 80% hwy. This past tank with 93 octane With the same driving variables and temps I"m averaging 45.5 mpg. This is the first time I've used gas above 87octane. Is this a know benefit to mpgs?
Higher octane gas has lower energy content and, in general, will give lower MPG in a car designed for regular. If the 93 octane gas is ethanol free, it can result in an MPG increase. JeffD
Curious about this, because I just found a station locally that sells ethanol-free gas, but only in 93 octane. I know the Prius isn't meant for high octane gas, so I was wondering if there would be any benefit (or detriment) to trying out this stuff. Thanks for any information!
It should not provide any benefit. I run the lowest octane that does not ping in my vehicles. Even my Camaro can run on 92 pump gas as long as I do not floor it. Prius and old beater escort run on 87. In overly simple terms, higher octane will create a bigger boom in the combustion chamber but requires more energy to do it. In cold weather higher octane can be more difficult to start. Too much octane actually reduces performance/efficiency. I run between 94-95 octane at the track. If I go higher performance drops off... Using gasoline without methanol will probably improve your mileage. Methanol is often used to increase octane at the expense of fuel mileage in consumer gasoline.
This question keeps coming up again and again. Higher octane fuel does not help (even can hurt) an engine's performance, unless the engine was designed to run on it. Decades ago only Premium fuels contained detergents to help clean the internal engine parts, so they really pushed consumers into using it even though their engines didn't require the higher octane. Today's regular fuels now have those detergents. Even if your engine requires the higher octane, many engines have a ping detector that can adjust the engine's timing for the fuel. For example the Corvette engine does this, so regular fuel doesn't harm the engine but there is some performance loss. So again, unless your engine was designed for higher octane fuel don't waste your money on it. And one of the points of owning a Prius is to save money.....yes?
Yes. It was one of the many questionable additives used during my college years in a brew we called "Wapitui"... Maybe that experience contributed to my brain hiccup.
