from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A substance, such as tetraethyl lead, added to gasoline to reduce engine knock.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. of an additive added to petroleum/gasoline to reduce the occurrence of engine knock.
- n. Such a substance, usually tetraethyl lead (also MMT, MTBE and ethanol)
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any of various compounds that are added to gasoline to reduce engine knocking
- adj. suppressing or eliminating engine knock in combustion engines
They replaced the last of the lead-like antiknock with ethanol in big part due toADM.
Distillate fuels and heavy oils were heated under pressure in large drums until they cracked into smaller molecules with better antiknock characteristics.
Moreover, cracked gasoline actually had a much better antiknock value than natural gasoline, which meant more power and allowed for higher-compression engines.
It was then discovered that cracked gasoline was actually preferable to “straight run” gasoline because it had much superior antiknock properties.
The important qualities for gasoline are octane number (antiknock), volatility (starting and vapor lock), and vapor pressure (environmental control).
Tetraethyl lead, gasoline antiknock additive, produced by Thomas Midgley (18891994).
ATL Racing Fuel Cells, Ramsey, NJ, May 30, 2008: Most unleaded racing fuels contain "ethanol" as an antiknock, but ethanol settles out if moisture gets into your fuel cell.
Check your car’s owner manual for the recommended fuel (unleaded gasoline versus diesel) and octane rating or antiknock index (on the yellow sticker affixed to the pump).
Most cars can optimize their own performance to the gas they’re fed, but only up to a certain point: Gas with too low an antiknock index causes an engine to fire prematurely and lose power.
Gas with an antiknock index well above the required octane level doesn’t increase performance or power, just your fuel costs.