Will I get better or worse gas millage with high octane gas in my car?

Question

I know high octane gas burns hotter at least i thought but does that mean i will get less MPG with high octane gas or would it be higher MPG because its more clean?

Answer 1

you'll only recover about half of what it cost you :(

Answer 2

Nothing would happen to your gas mileage, because octane rating has nothing to do with gas mileage. It has to do with how much compression the gas can withstand before self igniting. Higher compression motors (things like turbocharged cars) need higher octane gas because otherwise the gas would ignite from compression itself before the motor reached top dead center. Put in the fuel specified by the manufacturer. Anyone who claims that higher octane gas got better gas mileage is either not using accurate records to record their mileage or, through the placebo effect, changed their driving habits unknowingly. Higher octane fuel does NOT burn cleaner, or better, or differently. Use what the manufacturer specified for the car, they have a lot more money into research and development on what gas to use than you make in a whole year.

Answer 3

The octane rating is a measure of the autoignition resistance of gasoline (petrol) and other fuels used in spark-ignition internal combustion engines. It's a measure of anti-detonation of a gasoline or fuel.

Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. Since higher octane fuels have higher activation energies, it is less likely that a given compression will cause knocking. (Note that it is the absolute pressure (compression) in the combustion chamber which is important - not the compression ratio. The compression ratio only governs the maximum compression that can be achieved).

It might seem odd that fuels with higher octane ratings burn less easily, yet are popularly thought of as more powerful. The misunderstanding is caused by confusing the ability of the fuel to resist compression detonation (pre-ignition = engine knock) as opposed to the ability of the fuel to burn (combustion). However, premium grades of petrol often contain more energy per litre due to the composition of the fuel as well as increased octane.

Using a fuel with a higher octane lets an engine run at a higher compression without having problems with knock. Many high-performance engines are designed to operate with a high maximum compression and thus need a high quality (high energy) fuel usually associated with high octane numbers and thus demand high-octane premium gasoline.

The power output of an engine depends on the energy content of its fuel, and this bears no simple relationship to the octane rating. A common myth amongst petrol consumers is that adding a higher octane fuel to a vehicle's engine will increase its performance and/or lessen its fuel consumption; this is false—engines perform best when using fuel with the octane rating they were designed for and any increase in performance by using a fuel with a different octane rating is minimal or even imaginary.

Using high octane fuel for an engine makes a difference when the engine is producing its maximum power. This will occur when the intake manifold has no air restriction and is running at minimum vacuum. Depending on the engine design, this particular circumstance can be anywhere along the RPM range, but is usually easy to pin-point if you can examine a print-out of the power-output (torque values) of an engine. On a typical high-rev'ving motorcycle engine, for example, the maximum power occurs at a point where the movements of the intake and exhaust valves are timed in such a way to maximize the compression loading of the cylinder; although the cylinder is already rising at the time the intake valve closes, the forward speed of the charge coming into the cylinder is high enough to continue to load the air-fuel mixture in.

When this occurs, if a fuel with below recommended octane is used, then the engine will knock. Modern engines have anti-knock provisions built into the control systems and this is usually achieved by dynamically de-tuning the engine while under load by increasing the fuel-air mixture and retarding the spark.

So, cutting the long story short, if your car is designed for high octane gas - use it. If it is not - you are not going to benefit from it.

Answer 4

better to a point. if your manufacturer reccomends 87 dont waste the money on 92. Our jeep runs great on 87, but on the other hand my moms range rover will not tolerate it. starts pinging and such. Go with the cheapest gas that your vehicle will run good on. i dont feel the added plusses of higher octane out weight the costs. AS LONG AS YOUR ENGINE IS DOING WELL ON THE LOWER OCTANE STUFF. hope this helps a little

Answer 5

Your mileage will most likely stay the same.

High octane gas doesn't burn hotter. It simply is harder to ignite, which makes it less likely to knock or ping.

If your car manufacturer recommends lower octane, and you don't have knock or ping you will get no benefit from high octane gas.

Answer 6

octane is an anti knock compound. It is used in high compression engines to stop knocking or what is known as pre-ignition This enables the air fuel mixture to resist ignition from the compression stroke a high compression motor It does not burn higher and will not give any better gas mileage

Answer 7

I have increased my mileage and gotten better performance by using a product from Fuel Freedom International. Here is the information: http://www.dfarley.myffi.biz/en/

Answer 8

The short answer. it will make no difference in your MPG. only in your WALLET

Answer 9

simply put...study after study says use the cheapest gas you can find if it dores not make your car PIng( see other answers)

Answer 10

ditto on above. exactly what gas engineer said on tv show.

Answer 11

Better