Customer Questions and Answers:
What is gasoline?
A: In general, gasoline is a complex mixture of many components, called hydrocarbons, which are refined from crude oil. These hydrocarbons are blended together to produce a fuel that’s used to power spark ignition, internal combustion engines. The recipe used for blending these hydrocarbons may vary from refinery to refinery. Finished gasolines, however, are required to meet certain specifications as defined by federal and state regulations and the American Society for Testing and Materials (ASTM).
What is ASTM?
A: The American Society for Testing and Materials (ASTM) is an organization made up of voluntary representatives from automobile manufacturers, equipment manufacturers, gasoline producers, and pipeline companies. Through this organization, specifications are developed for gasoline in order to provide a product which will provide satisfactory performance, under varied operating conditions, for all automobiles.
What about ethanol? What does it do to my engine?
A: Gasoline containing ethanol in concentrations up to 10 percent has been determined by auto manufacturers to be a satisfactory fuel for most late model vehicles. It is recommended, however, that you consult your owner’'s manual before using ethanol-blended fuel to ensure that your equipment is compatible with this type of fuel. Furthermore, vehicles operating on gasoline containing ethanol may experience a decrease in fuel economy due to the lower energy content of ethanol.
What is meant by Octane?
A: The Antiknock Index, commonly referred to as Octane, is a measure of a gasoline’s ability to resist preignition, or engine knock. The Antiknock Index posted at the retail pump, such as 87 Octane, is the result of a formula which most closely depicts the average resistivity of the gasoline to engine knock. This average is displayed on the gasoline pump with a sticker showing (R+M)/2 Method. The Research Octane Number, or R in the equation, is a measure of the gasoline’s ability to resist knock at low speed under relatively mild operating conditions, such as city type driving. The Motor Octane Number, or M in the equation, is a measure of the gasoline’s ability to resist knock at high speeds and under severe operating conditions, such as towing a boat or climbing steep hills. The average of these two numbers defines how well the gasoline will resist engine knock under most conditions.
What is engine knock?
A: Engine knock is a sharp metallic noise, sometimes referred to as engine clatter or pinging, caused by the pre-ignition of fuel as it’s compressed in the cylinder, milliseconds before the normal spark plug firing. This condition typically occurs during acceleration, such as merging into highway traffic, or under heavy load conditions, such as pulling a boat or travel trailer. Under knock conditions, a vehicle will experience a reduction in power output as well as reduced fuel economy.
What causes engine knock, and how can I prevent it?
A: Several factors can contribute to, or result in, engine knock. These factors include outdoor temperature extremes, altitude, humidity, operating under heavy engine loads, time elapsed between routine tune-ups, vehicle age, and manufacturing and engineering tolerances. The most common cause of engine knock is improper tuning of the engine, where the engine timing has deviated from the manufacturer’s design specifications. This problem is easily resolved through proper routine maintenance and tune-ups.
As a vehicle’s engine ages, the octane required to prevent knock may increase. This condition is referred to as Octane Requirement Increase, or ORI, and is the result of normal engine wear. In instances where you experience occasional or moderate knocking, your first line of defense is to try a higher octane gasoline to accommodate this Octane Requirement Increase of your engine. Severe knocking, which cannot be remedied by using a higher octane grade of gasoline, demands your authorized mechanic’s attention.
So, which gasoline octane grade should I use in my car?
A: Your first reference should be the vehicle Owner’s Manual. Each automobile manufacturer includes, in the Owner’s Manual, the recommended minimum octane for normal operation of the vehicle. As a general rule of thumb, however, use the octane grade which prevents your engine from knocking or pinging.
If I use the appropriate octane grade for my car, why do I also need a detergent additive?
A: Un-additized gasoline can leave harmful deposits in today’s fuel systems, which are technically advanced and highly sensitive to such deposits. Over time, as these deposits accumulate, a vehicle can develop drivability problems such as hesitation, loss of power, poor acceleration, rough idle or even stalling.
What is Reformulated Gasoline?
A: The Clean Air Act of 1990 identified specific areas in the United States with higher concentrations of air pollutants. To improve air quality, the Environmental Protection Agency mandated that certain of these areas would require Reformulated Gasoline (RFG). RFG is gasoline which has been specifically manufactured to reduce undesirable emissions from vehicles. RFG must meet more stringent specifications compared to conventional gasoline (non-RFG). These more stringent specifications, which also require the addition of oxygenates to the gasoline blend, reduce air pollutants from vehicles. The oxygenates provide additional oxygen in the combustion chamber and thereby result in a more complete combustion of the gasoline.
Will Reformulated Gasoline work in my car?
A: Yes. In fact, all automobile manufacturers have approved Reformulated Gasoline for use in their vehicles.
How will using Reformulated Gasoline affect my car’s fuel economy?
A: While gas mileage is largely affected by driving habits and vehicle maintenance, use of RFG may result in a slight decrease in fuel economy of up to 3 percent.
Can I use RFG in my off-road equipment such as a snowmobile, weed trimmer, chain saw, or boat motor?
A: For such equipment, you should consult the owner’s manual or contact the manufacturer regarding any questions about using RFG.