is there a real difference between premium and regular unleaded? or is it just a gimmick?

Question

also, which gas stations are the best to buy from? I usually buy chevron or shell.

Answer 1

What you are reffering to is called the OCTANE a measure of the autoignition resistance of gasoline (petrol) and other fuels used in spark-ignition internal combustion engines.

Octane is measured on a scale of 0-100. In America, you are probably used to seeing 87 (regular) , 89 Premium and 93 Ultra.
These are just marketing terms used for people who are not educated about the gasoline refinery grades.


To make it simple for you, Octane ratings point to the amount of "knock" expected from the engine's burning of the fuel.
Engine knocking is compression detonation of fuel in the power stroke of the engine. Knocking occurs when the air-fuel mixture autoignites all at once (or sometimes perhaps when the flame front goes supersonic because of early ignition timing), before the flame front from spark plug ignition can reach it. The explosive reaction causes combustion to stop before the optimum timing, causing a decrease in performance. A fuel with a high autoignition temperature that burns reasonably fast and thus does not need early ignition timing will most often have high practical value knock resistance. Ethanol is such a fuel.

Basically the higher the octane, the lower the KNOCKING and the more combustible the fuel.

NEwer fuels such as ETHANOL E85 are composed of 85% Ethanol and 15% gasoline.
Ethanol which is an alcohol has higher octanes than similar gasolines, less knock and burns cleaner and cooler than gasoline BUT, since Ethanol is corrosive it damages car's fuel lines that can't resist its properties of corrosion.
That is why your current gasoline is only mixed with 10% ethanol rather than 85%. E85 is coming to most cities in the next 5 years.

Airplane fuel for military jets is of the highest octane because it must be volatile enough so that the engine won't "flame-out" in combat manuevers.

Some cars such as luxury sports cars and luxury SUV's require no less than 93 because they require a fuel that burns quickly, and in its entirety with no knock. Take for example a RR Phantom. If you use that car with 87 Octane, you will hear the engine knocking and eventually you will damage the engine.

Super Luxury cars such as the Bugatti Veyron require no less than 97 Octane (Racing Fuel) which costs $8 a gallon.


I'd say the best gaoline stations to buy from are BP, EXXON, SHELL, and HESS. These are well-known, trustable gasoline marketers who are more likely to sell you what you pay for than to try and rip you off by adding water to your gas or selling you false octanes.

Answer 2

the number denotes the octane rating. basically it's more bang for the buck. A higher octane will have a higher energy in the ignition phase of a four stroke engine. It's all about carbon compounds. Some engines need higher octane--like race cars, jets, etc. Jet A fuel is one hundred something octane. In a regular normal car, your owner's manual will tell you which gas you can use to get the best mileage. If you have a high performance Porsche or Vette then you will need to use higher octane due to the engines higher compression ratio. If you use a lower octane in a high performance engine, you get pre-ignition. In other words the gas/air mixture in the cylinder ignites before the spark and since the timing is wrong, it messes up the engines performance. Chevron/Texaco Corporation fuels are about the best for performance and I think BP/Amoco Corp's fuel has been rated the cleanest.
And in actuality I think there are only like 5 producers of gasoline anyway. Chev/Tex, Exxon/Mobil, BP/Amoco, Sunoco and one other. These 5 make gasolines for everyone.

Answer 3

Premuim gasoline has a higher percentage of octane in it. However, you should stick to the octane rating recommended by the manufacturer. The manufacturer's recommended octane rating can usually be found in your vehicle's owners manual or on the inside edge of the driver's door, near the latch. The fuel rating is usually given on the gas pump (about 87 for regular unleaded up to as much as 93 for the "super premium" types). May God bless and keep you.

Answer 4

The refineries sell the same gas to all of them, so it doesn't matter which brand. The octane level does make a difference, and you should stick with what the manufacturer of your car recommended. But some stations sell the 10% ethanol gas which usually gives you a higher octane for the same price as the other stations charge for non-ethanol gas. More octane gives better mileage, and if it is the same price per gallon, go with the octane.

Answer 5

The differences are in the amount of octane in the fuel. Regular gas is rated 87, whereas premium fuel is rated 93.

Engines with higher compression usually require 93 octane fuel to run at their optimum and avoid damage over the long run. Although you can put regular in such a car, the engine management system has to retard the timing to prevent engine ping and knock (premature ignition of the fuel in the cylinders).

Also, premium usually has detergent additives in it to help clean fuel injectors.

If your car says it will run on 87 octane (consult the owner's manual) then use it.

Answer 6

There is a real difference, most cars and trucks are designed to run better on regular so people are just wasting their money buying premium. I just go to the closest gas station that is open! (Live a long ways from towns with more than one or two at the most)

Answer 7

Yes, octane! middle grade is mixture of 87 and 93. I wouldn't run 87 in my lawnmower. Premium is real gas. And it will do less damage over a period of time than 87. Yes I understand burn rates ,for all you engineers out ther. Gas is not what it used to be,87 in particular. Your not getting it. And by the way ,buy gas from a busy station that's not to old. Doesn't matter who.

Answer 8

There is a difference I'm just not sure what exactly.
My boyfriend's car is supposed to use premium only, but he had always but regular in it because regular was cheaper. Now he is putting the correct gas in and even though it costs more upfront, he is getting much better gas mileage on his car with the premium gas.

Answer 9

I had a car that was 5 years old and the engine would make a lot of noise when I put 87 octane in. I switched to 93 octane and the noises stopped. Kinda makes you wonder if those noises are causing permanent damage to your car. Ever since then I only use 93 octane.

Answer 10

Yes. Octane ratings = hotter burning gas. It is not needed on most vehicles, except sporty rides. But once in a while it can assist in a cleaner running engine. Check your owners manual, some will tell you NOT to use premium fuel.
Other than some additives, they all come from dead dinosaurs.