{{Short description|Measure of internal combustion engine performance}} '''Specific output''' is a measure of internal combustion engine performance. It describes the efficiency of an engine in terms of the brake horsepower it outputs relative to its displacement. The measure enables the comparison of differently sized engines, and is usually expressed as kilowatts or horsepower per litre or per cubic inch.<ref>{{cite web|url=http://www.caranddriver.com/features/2012-10best-highest-specific-output-engines-features|title=2012 10Best: Highest-Specific-Output Engines|date=6 December 2011|publisher=|accessdate=10 February 2016}}</ref> On average, forced induction engines out-perform naturally aspirated engines by this measure, primarily due to their increased volumetric efficiency.<ref>{{cite web|url=http://www.thetruthaboutcars.com/2015/07/average-gas-engine-specific-output-isnt-quite-100-hpl-yet/|title=Average Gas Engine Specific Output Isn't Quite 100 HP/L, Yet|author=Mark Stevenson|date=28 July 2015|work=The Truth About Cars|accessdate=10 February 2016}}</ref>
==See also== * Power density * List of automotive superlatives
==References== {{reflist}}
Category:Engine technology