How Can I compare oil quality?

Answer: Oils are certified by a couple of major international organizations, in particular the North American API (American Petroleum Institute) and the European organization, ACEA. The most commonly referred to specification is the API system. For gasoline engine passenger cars, this system always uses the letter S followed by a letter which implies the performance level of the oil. For example, the first specification was designated "SA", the next was "SB, the next was "SC" and so the pattern continues up to the current "SL". The API system for diesel engines replaces the letter S with the letter C. The current designation for 4-stroke diesel engines is "CI-4". The certification is based on extensive engine and laboratory tests as specified by these organizations in conjunction with engine manufacturers.

How Come Engine Oils Can Vary Substantially in Price?

Answer: First of all you need to compare the API rating. It is not much good in comparing the price of an oil meeting API SF to that of an oil meeting API SL. The oils have different additive systems and additives are expensive. The API SF oil was developed in the late 70's and is cheaper to manufacture (due, in part, to lower additive levels) than, say, an API SL oil which was developed in the mid 90's.
Secondly, oils of the same API rating can be made to just meet the specifications, or made to greatly exceed the specifications. However, unless you can see the full engine test results, it is impossible to tell the degree to which these oils pass the specification. Only in-service experience will tell which is the superior product.
Thirdly, there is the issue of cost recovery. Qualifying an oil to meet the latest ratings is an extremely expensive business. The oil manufacturer must recover these costs, which can amount to hundreds of thousands of dollars.

How To Determining Fuel Prices?

Answer: Consumers worldwide have watched the cost of petroleum (motor fuels) continue to fluctuate throughout the year. This raises the question,
In the long term, the greatest single factor influencing petroleum prices is the cost of crude oil. However, marketplace forces of supply, demand and competition can have a significant effect on the price of petroleum in the short term.

How About The Cost of Crude?

Answer: Crude oil prices have risen dramatically over the last year, driven by strong global demand, limited spare oil production capacity, and continuing political instability in certain oil producing regions.
Since the price of crude oil has the most significant long-term impact on the average price of petroleum, contributing over 50 percent to the retail price, it is not surprising to see average petroleum prices significantly higher as well.

How About The Increase in International Energy Demand?

Answer: Surging crude oil demand is being fueled by strong economic growth, particularly in the United States and Asia. The U.S. Energy Information Administration estimates that global crude oil demand will grow 2.5 percent in 2005, reaching 84.7 million barrels per day. Available spare oil production capacity is currently about one percent of total worldwide demand, leaving very little room to compensate for unanticipated supply disruptions or spikes in demand. The tenuous balance between supply and demand is even more of a concern when you consider that most of the world's oil is located in some of the more politically unstable parts of the world. As such, supply disruptions, whether real or perceived, can have dramatic effects on the price of crude oil.
Global economic expansion is driving what the U.S. International Energy Agency (IEA) says is the biggest increase in oil demand in 24 years. In particular, industrialised countries such as the US and Asia have had a demand surge.
China's rapidly expanding economy has created a huge demand boost and US demand has risen because of its strengthening economic recovery and greater need for higher grade crude oil suitable for processing into petrol (gasoline) for SUVs, which are popular with US drivers.

About Oil Supply - Uncertainty is Placing Pressure on Price

Answer: Crude oil is refined to produce petrol and diesel and the cost of crude oil is traditionally the greatest single factor affecting fuel prices over time. However, with the shortage of refineries to refine the crude we are in a unique situation where the price difference between crude oil and refined product can be large.
Supply remains volatile. A number of other factors also increase uncertainty of supply and with rising demand, this is placing tremendous pressure on pricing. Political volatility in oil producing regions has historically impacted on crude oil prices and the political situation in the Middle East is of global concern.