I found the following article on Tulane University's Internet site and thought it could provide some basic information on gasolines that might be of interest to Ferrari owners. It is adapted from a very lengthy and fairly technical description of what gasoline contains, how it is specified, and how the properties affect the performance in your vehicle. Note that it does not discuss the relative advantages of specific brands of gasolines, it is only intended to discuss the generic properties of gasolines. All in all, this article represents less than 1/50th of the original article. The original can be found on the Internet at: http://ram.chem.tulane.edu:8080/f-body/trivia/trivia.html
Where does crude oil come from?
The generally-accepted origin of crude oil is from plant life up to 3 billion years ago, but predominantly from 100 to 600 million years ago. "Dead vegetarian dino dinner" is more correct than "dead dinos". The molecular structure of the hydrocarbons and other compounds present in fossil fuels can be linked to the leaf waxes and other plant molecules of marine and terrestrial plants believed to exist during that era.
When will we run out of crude oil?
It has been estimated that the planet contains over 1.4 x 1015 tons of petroleum, however much of this is too dilute or inaccessible for current technology to recover. The petroleum industry uses a measure called the Reserves/Production ratio (R/P) to monitor how production and exploration are linked. This is based on the concept of "proved" reserves of crude oil, which are generally taken to be those quantities which geological and engineering information indicate with reasonable certainty can be recovered in the future from known reservoirs under existing economic and operating conditions. The Reserves/Production ratio is the above reserves divided by the production in the last year, and the result is the length of time that those remaining reserves would last if production were to continue at the current level. It is important to note those definitions, as the price of oil increases, marginal fields become "proved reserves", thus we are unlikely to "run out" of oil, as more fields will become economic as the price rises. If the price exceeds $30/bbl then alternative fuels may become competitive, and at $50-60/bbl coal-derived liquid fuels are economic, as are many biomass-derived fuels and other energy sources. The current price for Brent Crude is approx. $18/bbl. The R/P ratio has increased from 27 years (1979) to 43.1 years (1993).
Are gasoline brands different?
Yes. There are specifications intended to ensure that minimal quality standards are maintained, however, the manufacturers add their own special ingredients to provide additional benefits. A quality gasoline additive package would include:
octane-enhancing additives (improve octane ratings) anti-oxidants (inhibit gum formation, improve stability) metal deactivators (inhibit gum formation, improve stability) deposit modifiers (reduce deposits, spark-plug fouling and preignition) surfactants (prevent icing, improve vaporization, inhibit deposits, reduce NOx emissions) freezing point depressants (prevent icing) corrosion inhibitors (prevent gasoline corroding storage tanks) dyes (product color for safety or regulatory pur-poses) During the 1980s significant problems with deposits accumulating on intake valve surfaces occurred as new fuel injections systems were introduced. These intake valve deposits (IVD) were different to injector deposits, in part because the valve can reach 300oC. Engine design changes that prevent deposits usually consist of ensuring the valve is flushed with liquid gasoline, and provision of adequate valve rotation. Gasoline factors that cause deposits are the presence of alcohols or olefins. Gasoline manufacturers now routinely use additives that prevent IVD and also maintain the cleanliness of injectors. These usually include a surfactant and light oil to maintain the wetting of important surfaces.
Texaco demonstrated that a well-formulated package could improve fuel economy, reduce NOx emissions, and restore engine performance because, as well as the traditional liquid-phase deposit removal, some additives can work in the vapor phase to remove existing engine deposits without adversely affecting performance (as happens when water is poured into a running engine to remove carbon deposits). Most suppliers of quality gasolines will formulate similar additives into their products, and cheaper lines are less likely to have such additives added. As different brands use different additives and oxygenates, it is probable that important parameters, such as octane distribution, are different, even though the pump octane ratings are the same.
So, if you know your car is well-tuned, and in good condition, but the driveability is pathetic on the correct octane, try another brand. Remember that the composition will change with the season, so if you lose driveability, try yet another brand. As various Clean Air Act changes are introduced over the next few years, gasoline will continue to change.
About the author:
The author of this information is Bruce Hamilton (B.Hamilton@irl.cri.nz). Look to future issues of Sempre Ferrari for more information of gasoline, covering subjects such as octane, lead, additives, oxygenates, etc.
For a complete look at Sempre Ferrari, you may want to check out the
rest of the articles from
Volume 2, Issue 8 - September 1995