Which gasoline brand provides the best fuel mileage?

Answer 1

• All gasoline comes from the same refineries. What matters is the additive that each brand adds to the gasoline. Good standard brands are Chevron, Texaco and then Mobil.
• It's true. All gas comes from the same distributor. Different brands, Shell/Mobil, Chevron/Texaco, Diamond Shamrock, etc. chemicals are then added after the tanker truck is filled.
• All the octane does is slow down the burning of gas. Cetane on the other hand, speeds up the burning of diesel fuel.
• Gasoline's will give similar gas mileage, but some have additives. Some cars need higher octanes to run better.
• Octane is a unit of measure. It describes the burn rate of gasoline as compared to pure Octane. Octane burns at 100% and 87 octane gasoline produces 13% less energy than pure octane. Octane is an eight carbon chain like methane (one carbon) or propane (3carbon chain). The octane rating of pure gasoline is around 55, the manufacturers add components like benzene to boost the octane rating to what engineers designed the engines to burn. So the higher the octane rating the faster the gasoline will burn.
• The answer where it was stated "ALL OCTANE DOES IS PREVENT YOUR CAR'S ENGINE FROM PINGING" is generally a pretty good answer to this. Octane truly is the gases ability to resist "knock". Knock is a technical term used to describe premature detonation due to compression. What this all boils down to is that certain high performance vehicles has high compression within their cylinders. This high compression squeezes the gas so much that it ignites before it is supposed to. Your cylinder is supposed to fire near top dead center when the pistons upward motion is almost stopped. When you have "knock" the piston is still traveling very fast upward and the combustion of gas forces the piston to move back down when it doesn't want to. This is what creates the "pinging" or "knock" that you hear from inside the engine. The best example I have of this is imagine that your fist is a piston and you punching something statiopnary is the motion of the piston. If you just stand there and punch something the impact is rather low and your arm wont hurt very much. Now imagine punching something that is coming towards you at a fast rate.... the impact is much greater and it will hurt your arm. That is a good way to vision what is happening during engine knock and why it is bad for your vehicle. So the octane rating determines its resistance to this premature detonation. A higher rating will not ignite as easily under compression. The higher rating WILL NOT, I repeat, WILL NOT increase your vehicles efficiency. That is not part of its design and is a common misconception that could save people a lot of money. That being said, If you car is supercharged, turbo charged or says it "recommends super unleaded" then please DO use it, as you can cause severe engine damage if you don't, as stated above.