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The mixture known as gasoline or petrol, when used in high compression internal combustion engines, has a tendency to knock (also called "pinging" or "pinking") and/or to ignite early before the correctly timed spark occurs (pre-ignition, refer to engine knocking). Notable early antiknock agents, especially tetraethyllead, added to gasoline ...
In the U.S. MTBE has been used in gasoline at low levels since 1979, replacing tetraethyllead (TEL) as an antiknock (octane rating) additive to prevent engine knocking. [19] Oxygenates also help gasoline burn more completely, reducing tailpipe emissions. Oxygenates also dilute or displace gasoline components such as aromatics (e.g., benzene ...
The octane rating of gasoline is measured in a test engine and is defined by comparison with the mixture of 2,2,4-trimethylpentane (iso-octane) and normal heptane that would have the same anti-knocking capability as the fuel under test. The percentage, by volume, of 2,2,4-trimethylpentane in that mixture is the octane number of the fuel.
A gasoline-fuelled reciprocating engine requires fuel of sufficient octane rating to prevent uncontrolled combustion (preignition and detonation). [9] Antiknock agents allow the use of higher compression ratios for greater efficiency [22] and peak power. [23]
Engine knocking is an unwanted process that can occur during high compression ratios in internal combustion engines. In 1926 Graham Edgar added different amounts of n-heptane and 2,2,4-trimethylpentane to gasoline, and discovered that the knocking stopped when 2,2,4-trimethylpentane was added. This work was the origin of the octane rating scale ...
Fuel additives in general Ether and other flammable hydrocarbons have been used extensively as starting fluid for many difficult-to-start engines, especially diesel engines; Nitromethane, or "nitro", is a high-performance racing fuel; Acetone is a vaporization additive, mainly used with methanol racing fuel
The fuel-characteristics of a particular gasoline-blend, which will resist igniting too early are measured as the octane rating of the fuel blend. Gasoline blends with stable octane ratings are produced in several fuel-grades for various types of motors. A low octane rated fuel may cause engine knocking and reduced efficiency in reciprocating ...
Methylcyclopentadienyl manganese tricarbonyl (MMT or MCMT) is an organomanganese compound with the formula (C 5 H 4 CH 3)Mn(CO) 3.Initially marketed as a supplement for use in leaded gasoline, MMT was later used in unleaded gasoline to increase the octane rating.