In the United States at least there are 3 grades of unleaded gasoline at most pumps. Does it really matter what grade of gas you use? Can I use the lowest grade one week and the next week get premium if I can afford it? Does it help with milage or does it keep your engine clean? What is the difference?
In: Engineering
A lot of engines are designed differently than others. Usually “high performance” engines use a higher grade of gas (91 or higher). This is to keep the engine running at its peak performance. Let’s say you bought a classic car with a beefed up engine and the seller tells you “it runs on 91 aka “premium gas” you drive it home it feels fine engine sounds great and is full of power. Now the next day you’re on empty so you pull into the gas station and fill it up and you decide to use regular gas (87 octane). The moment you start that car you hear sounds coming from the engine. These sounds can be described as knocks or pings. This is due to the “lower octane rating” of the fuel. Regular gas (87 octane) has a lower threshold for igniting compared to premium gas (91 octane). In the car you purchased the engine is designed to run at higher pressures and higher temperatures that only premium gas (91) can withstand. When it was filled up with regular gas the pressures and temperatures of the engine was causing the regular gas (87) to ignite prematurely causing the sounds and poor performance from the engine.
For all intents and purposes this is the only difference in the fuel between premium and regular. For a car designed for regular gas, premium does not provide better gas mileage, premium does not keep your engine cleaner. Premium does not increase power. To use it thinking premium is better for your car is a waste of money.
I hope this helps clear some things up for you
There is no such thing as premium gasoline. That is a marketing word. What we have is gasoline with different octane (or RON) ratings. The octane your engine needs is mostly based on engine compression among other things.
If your vehicle is rated for 87 octane you will gain nothing by putting in a higher octane gasoline.
If your car is rated for 93 octane but you use a lower octane it can cause pinging or knock. Modern vehicles have a sensor that detects this and the engines computer will adjust the timing of the engine which results in less power output.
In the United States all gasoline has fuel additives to clean out your fuel system and engine of gunk and deposits. It is [federally mandated.](https://www.epa.gov/gasoline-standards/federal-gasoline-regulations)
There is a list of [top tier fuel brands](https://www.toptiergas.com/licensed-brands/) that are supposed to do a better job of ensuring a higher quality of gasoline to begin with, proper mix of fuel additives and better fuel storage techniques. Personally I recommend Shell or Texaco.
“What grade of boomliquid is required for my rollmachine?” What a strange planet.
One of the fundamental basics of engines is that you want the air/fuel mixture to burn in a controlled manner, not explode. When the air/fuel mixture does explode, this is called knock, and can destroy engines pretty quickly.
Gasoline is rated according to its resistance to knock. This varies from engine to engine, as well as factors such as how hard the engine is working, how hot it is, how hot the air/fuel mixture is before ignition, and others.
The general rule is to use the grade of gasoline recommended by the manufacturer, although there are some exceptions to this. My wife’s Chevy Cruze has a turbocharged engine, and I have found that it seems to be a lot happier on premium fuel. I could probably get by with super, but since our other car is a VW GTI tuned for about 290hp, I’m used to spending the extra money on gas anyway.
For most cars that are tuned for regular, using premium is just a waste of money. It won’t clean your engine – gasoline already contains detergents that do that. It won’t necessarily improve your fuel economy – engines that run on premium tend to be more efficient, but they have to be tuned for it, so if your car is tuned for 87 octane, 91 or 93 won’t help you at all.
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