Mazda: Car Fuel, gasoline vapor, accelerator pedal

Question
I have a 2003 Mazda 6 with 82000 miles and have been using regular Gas. Is that fine or shall i need to start using premium? what is the basic difference and how will it effect the car, keeping in mind the way gas prices are soaring these days. Please advise.

Thanks,
Manish

Answer
With regards to the first part of your question, I do not specifically know whether or not your car needs to be run on premium. You should be able to consult your owners manual for that information.

To understand the basic difference between premium and regular, one must understand how compression works. When a gas is compressed, it is forced to occupy less space while retaining the same amount of energy. This energy is in the form of heat. So, as the gas is compressed -in this case the gas is a mixture of air and gasoline vapor- it gets hotter.

It is also important to understand what a flash point is. A flash point is the temperature at which a substance will combust.

In this case the substance is a mixture of approximately 14 parts air and 1 part gasoline. Different grades of gasoline have different flash points. Regular gasoline has a lower flash point while Premium's flash point is higher. If regular gasoline is used in a car that requires premium, the fuel mixture will ignite prematurely. When this happens engine damage can occur. In this event, the driver will generally hear a pinging or knocking sound when the accelerator pedal is pressed down.

If your owners manual specifies premium, then you should definitely use premium. Also, if you hear a knocking sound while accelerating, then you should definitely use premium.