Date: Fri, 6 Dec 1996 23:28:18 -0600 From: Thomas M. David Subject: Re: Gasolines formulations To those interested in strange stuff re. fuel and gasoline Gasoline as we know is a complicated chemical stew of oxygenated hydrocarbons and a wild variety of other complex chemicals. As lay men we tend to think of gasoline as one homogeneous product with simple differences in octane. The whole " re-formulated " debate ( nightmare ) has opened a number of eyes including this writers. I am just beginning to understand some of the basic chemistry behind " gasoline ". Some of you might be aware that a few years ago Formula 1 teams were blending highly specialized brews all of them met the maximum octane rule , 104 as I recall. They would use gas blend A at track X and then gas blend B at track Y. This stuff gave them very small but measurable improvements in mileage, peak horsepower etc. In simple terms they were tailor making each liter of " gas " to fit very specific engine performance characteristics. It was widely reported that the major F1 teams were spending $ 600 per LITER for these special gasolines. That is not a typo Six Hundred Bucks per Liter!!!!!!!!!! What does that have to do with VW's? Lots. There is one quality in particular that has a dramatic effect on the performance of Gasoline and that is called REID Vapor Pressure. Basically this is a component that oil companies tailor for given climatic conditions. Fuel that performs optimally when the ambient temperatures are between 50 and 90 F isn't going to work well when old man winter arrives, and vice versa. At times here in the mid west we experience fairly dramatic temperature shifts and the number of cars that won't start, or run poorly, or " ping " is significantly increased. It seems especially bad when the oil refineries are running a bit behind or ahead of seasonal changes. What can you do about it? Anticipate dramatic temperature shifts and just wait them out. Keep your car in top running order. Install a CDI if you don't have one. Go to the local Drag Race or Sprint Car guys a beg or buy a couple of gallons or so of their 104 non-highway use gas, and mix it with what you get from the pump. About 2 gallons Union 76 104 octane mixed with 10 gallons of unleaded premium is MAGIC. Learn to mix your own fuels. Dangerous, expensive, often illegal, and a big hassle. Be absolutely certain that I can not, will not, and am not, recommending non-highway gasoline for use on the public highways as that is illegal. But I use it in every motor I can. tom