Save money on gas: the octane factor
With the price of gas these days (over $ 3.00 per gallon at the time of this writing) most people
they are feeling the financial hardship and wondering what they can do to cut their gas costs. This article presents one of several ways to earn as many miles per dollar as possible.
When it comes to the grade of gasoline or octane you put in your car, “More is better”, right?
Not always. There are a number of myths surrounding the use of high octane gas.
Myth No. # 1: Using high octane gasoline will make my car run better.
Not quite. If your car is “pinging” or “banging,” a higher octane gas will help or remove the ping and save your engine, but it doesn’t directly add horsepower. However, it prevents your electronic ignition from delaying timing as an “anti-knock” measure when a ping is detected.
Myth No. 2: My car will get more miles per gallon by using a higher octane gas.
Since higher octane gasoline does not produce more power, you will not get better gas mileage.
Myth No. # 3 – My engine will run cleaner and produce less emissions and smog with a higher octane gas.
Is not true. Many oil company advertising methods may have you believe this, but octane has nothing to do with how “clean” your engine is.
Myth No. 4 – Octane is added to gasoline to produce a higher quality fuel.
No actually Octane it is gasoline, at least most of it. See the octane rating below.
You can save money on gas simply by using the lowest octane gasoline your car will tolerate. Using a higher octane
gas from what the manufacturer says is simply a waste of money. If you’re not sure what octane your car is designed for
To use it, you can start with the lowest octane gas (87 in most areas) and give it a try. If you ping under load, move to
next octane and only buy the lowest octane your car needs. To learn more about octane, read on.
What is “ping” or “hit”?
Most of us have heard the rattling noise under the hood, usually when the engine is under additional load like
up a hill, towing a boat or in a loaded truck. The noise itself is produced when the air-fuel mixture in the
compression chamber ignites too early (pre-ignition or detonation). This condition causes the air fuel mixture to burn unevenly and
Produces the pinging or hitting sound. This uneven burn causes flash points in the combustion chamber and can lead to engine damage.
What does Octane do?
Without going into all the chemical properties and technical aspects, basically the octane increases the
Combustion point of gasoline when under compression and retards combustion. The result is that it does
Gasoline is less volatile so it doesn’t ignite before your ignition system causes it to ignite at the correct time.
The intention of octane is simply to provide an anti-knock property.
The octane number you see in the gas pump is simply a percentage of the octane chemical in the
gasoline mixture. In other words, if you buy gasoline with an 87 octane rating, that mixture contains 87% octane and
the rest are lower-quality chemicals like heptane. See also http://en.wikipedia.org/wiki/Octane_rating
What about “Octane Boost” additives?
If your car requires higher octane gasoline, you can use “Octane Boosters” available at your local auto parts store. The cost
and the effectiveness will vary. Test a tank filled with an additive to see if your can works properly and then do the math to see
if it makes sense. Here’s a cost analysis for my 1993 Mustang GT:
Example: 1 bottle of additive to power a tank of gasoline costs about $ 5.00. With a 15 gallon tank, this adds about $ .33 to the cost of each gallon of gasoline, plus the hassle of going to the auto parts store to buy it and remembering to add it at every fill.
If you really want or need a high octane mix, you can make your own.
Homemade Octane Booster
There are a number of websites and blogs that post the recipes or “homemade”. I’m not going to post it here because I can’t directly endorse the
use or safety to do it yourself. However, if you are looking for a xylene or toluene octane booster recipe, you will find it out there. The chemists
xylene and toluene are of higher “quality” and can produce an increase of more than 100%. Chemical octane alone by definition can never produce more than one
octane rating over 100.
Other ping solutions
If your car continues to ping or bump even though you are using an octane gas with an octane rating equal to or higher than that specified by your car manufacturer, this
it is an indication of engine problems that you should have your mechanic check. There is a well-known problem that you may be able to
try to diagnose yourself and that is the case with a stuck or failing EGR valve. It is beyond the scope of this article to explain how to verify
your EGR valve, but it is something to examine if your car has a chronic ping problem.