Yes, gasoline is a commodity. It is often stored in common tanks and distributed to various wholesalers via common pipe lines. However, important additives are added at the wholesale distributer’s facility prior to shipping to retailers. In 2004, a petroleum industry standard for fuel additives was established. Fuels meeting this standard were designated “Top Tier.” Many car manufacturers require that owners use “Top Tier” motor fuels only. AAA did a study and confirmed that the extra two or three cents charged for Top Tier fuels were well worth the cost. Better mileage and performance along with reduced repairs were shown to result. Go to toptier.com on your computer where you will find a list of brands that meet the Top Tier standard.

I must destroy a common fuel myth! If your car requires only 87 octane gasoline but you purchase 89 or 91 octane, only your fuel cost goes up. Yes, I have heard many tales of 2-3 MPG improvement in fuel mileage and noticeably greater engine power. What I have never seen is a scientifically conducted study that in any way confirmed this myth. Octane is only a measure of “engine knock suppression.” Once octane high enough to prevent preignition knocking or “pinging” is used, higher levels are a waste and only increase fuel cost. However, using a lower octane than required will not produce “pinging” because the engine management systems in modern cars detect the pinging and reduce certain performance settings to prevent damage. These changes do reduce performance as well as fuel economy.

Using the correct motor oil for your car and changing the oil and oil filter regularly is one of the most important service items that will extend the life and performance of your car’s engine. First, check your car's manual to determine the correct “weight” or viscosity oil to use. It is very important to use only the weight listed for your car. My car requires “0W-20”. The “O” indicates the viscosity or thickness of the oil when the engine is started cold during the Winter (“W”).  “20” indicates the viscosity when the engine is operating at high temperatures. Next is the standard tests the oil must meet. In my car it is “ILSAC GF-5”. This is the International Lubricant Specification Advisory Committee, GF 5 testing standards. Higher standards may be used but never lower. Oil changes should occur in accordance with requirements in the auto’s manual. Time is as important as miles relative to oil life.

My next post will cover other, longer term fluids and filters.