User:PengChaLi/Current Project 2

Reference for use of lead in aviation
 * Updates for Gasoline page

Reference for use of lead in auto racing

Discussion of density impact on pricing
When gasoline is shipped in large quantities, the cost is invoiced based on the weight of fuel shipped. However, it is not possible to accurately determine the weight of fuel in a tanker directly. Nevertheless, the volume is known, so the density of the fuel is used to convert the volume to the weight of fuel for pricing. However, this is not really the problem. The problem is clarification of the sentence: Finished marketable gasoline is traded (in Europe) with a standard reference of 0.755 kg/L (6.30 lb/US gal), and its price is escalated or de-escalated according to its actual density. So add the following text: For example, at the end of July, 2020, the average wholesale price of gasoline in the UK was 79.88 pence/litre. Bah Gave up on this and suggest deleting the sentence. Put a proposal in the Talk page to that effect.

Addition of reference in Octane section
The following sentence needs a citation: In the United Kingdom, ordinary regular unleaded gasoline is sold at 95 RON (commonly available), premium unleaded gasoline is always 97 RON, and super-unleaded is usually 97–98 RON. However, on review, I find that this sentence is out of date. It appears that more recently, fuel is sold at two octane levels, 95 and 97/98. 12th Annual EU report has UK data: min RON=95 17370 million lit, min RON=98 650 million lit, min RON>98 no data The majority of [EU] petrol sales in 2017 comprised fuels with a petrol grade research octane number (RON) of 95, which accounted for 85.7 % of the total petrol fuel sales; 8.3 % of sales were 95 ≤ RON < 98; and 5.8 % were RON ≥ 98. There was an insignificant proportion of RON = 91 sales.

I will replace the offending sentence with the following: In the UK, the over 95% of gasoline sold has 95 RON, and is marketed as Unleaded or Premium Unleaded. Super Unleaded, with 97/98 RON and branded high-performance fuels (e.g. Shell V-Power, BP Ultimate) with 99 RON make up the balance. Gasoline with 102 RON may be available for racing purposes.

MMT Section Update

 * As is

Methylcyclopentadienyl manganese tricarbonyl (MMT) is used in Canada and the US to boost octane rating. It also helps old cars designed for leaded fuel run on unleaded fuel without the need for additives to prevent valve problems. Its use in the United States has been restricted by regulations. Its use in the European Union is restricted by Article 8a of the Fuel Quality Directive following its testing under the Protocol for the evaluation of effects of metallic fuel-additives on the emissions performance of vehicles.

The following links cover detailed information on MMT, especially the regulatory, performance, and health issues: Bottom line, while MMT is not banned in the US, it is not much used, either. The widespread "top tier" designation explicitly prohibits it. It still sees some use globally.
 * https://www.sae.org/publications/technical-papers/content/2016-01-9073/
 * https://toptiergas.com/licensed-brands/
 * https://forums.redflagdeals.com/brand-contains-mmt-1332089/
 * https://www.consumerreports.org/car-maintenance/study-shows-top-tier-gasoline-worth-extra-price/
 * https://www.consumerreports.org/car-maintenance/study-shows-top-tier-gasoline-worth-extra-price/

To the question of, does the additive MMT prolong valve life in older engines designed for use with tetraethyl lead? The following statement is flagged in the current article: It also helps old cars designed for leaded fuel run on unleaded fuel without the need for additives to prevent valve problems. I recommend deleting this statement. One report seems to indicate it does not help with this issue. There are no claims on the manufacturer's web site that it performs this function.

One must beware of circular references supporting unattributed statements. Here is an example from PediaPress, which is a Google Book autogenerated from this Wikipedia article.

Updated version: Methylcyclopentadienyl manganese tricarbonyl (MMT) is used in Canada and the US to boost octane rating. Its use in the United States has been restricted by regulations, although it is currently allowed. Its use in the European Union is restricted by Article 8a of the Fuel Quality Directive following its testing under the Protocol for the evaluation of effects of metallic fuel-additives on the emissions performance of vehicles.

United States
Working copy - still need to check the E10 statements - out of date The federal Renewable Fuel Standard (RFS) effectively requires refiners and blenders to blend renewable biofuels (mostly ethanol) with gasoline, sufficient to meet a growing annual target of total gallons blended. Although the mandate does not require a specific percentage of ethanol, annual increases in the target combined with declining gasoline consumption has caused the typical ethanol content in gasoline to approach 10%. Most fuel pumps display a sticker that states that the fuel may contain up to 10% ethanol, an intentional disparity that reflects the varying actual percentage. In 2011, the US Environmental Protection Agency approved the sale of fuel containing up to 15% ethanol (E15) and use in cars from model year 2001 and later. As of model year 2019, 85% of new car model warranties authorize the use of E15 fuel, although for older cars, the use of E15 is not universally endorsed. In parts of the United States, ethanol is sometimes added to gasoline without an indication that it is a component.

Vapor Pressure and Ethanol
Existing text The main concern with gasoline on the environment, aside from the complications of its extraction and refining, is the effect on the climate through the production of carbon dioxide. Unburnt gasoline and evaporation from the tank, when in the atmosphere, reacts in sunlight to produce photochemical smog. Vapor pressure initially rises with some addition of ethanol to gasoline, but the increase is greatest at 10% by volume. At higher concentrations of ethanol above 10%, the vapor pressure of the blend starts to decrease. At a 10% ethanol by volume, the rise in vapor pressure may potentially increase the problem of photochemical smog. This rise in vapor pressure could be mitigated by increasing or decreasing the percentage of ethanol in the gasoline mixture.

Attempted references for ethanol gasoline vapor pressure.

Health Effects
Reference for health effects

Comparison with other fuels

 * Reworking this table

Below is a table of the volumetric and mass energy density of various transportation fuels as compared with gasoline. Heating values fall into two categories, usually referred to as “higher” (or gross) and “lower” (or net). If the products of fuel combustion are cooled back to the initial fuel-air or fuel-oxidizer mixture temperature and the water formed during combustion is condensed, the energy released by the process is the higher (gross) heating value. If the products of combustion are cooled to the initial fuel-air temperature, but the water is considered to remain as a vapor, the energy released by the process is the lower (net) heating value. Usually the difference between the gross and net heating values for fuels used in transportation is around 5 to 8 percent; however, it is important to be consistent in their use.

(*) Diesel fuel is not used in a gasoline engine, so its low octane rating is not an issue; the relevant metric for diesel engines is the cetane number.