Italian tuneup is a
slang
Slang is vocabulary (words, phrases, and linguistic usages) of an informal register, common in spoken conversation but avoided in formal writing. It also sometimes refers to the language generally exclusive to the members of particular in-g ...
automotive term for attempting to restore engine performance by driving a car at high engine speed (RPM) and load.
The term originated from Italian mechanics in the 1950s using this practice to burn off carbon deposits from the
spark plugs of sports cars.
However, modern
fuel injection and
ignition system
An ignition system generates a spark or heats an electrode to a high temperature to ignite a fuel-air mixture in spark ignition internal combustion engines, oil-fired and gas-fired boilers, rocket engines, etc. The widest application for spark i ...
s have rendered Italian tuneups obsolete for that particular purpose.
The practice is sometimes used prior to emissions testing, particularly for diesel engines.
References
Automotive terminology
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