Editing Compression ratio (section)

===Other fuels===
The compression ratio may be higher in engines running exclusively on [[liquefied petroleum gas]] (LPG or "propane autogas") or [[compressed natural gas]], due to the higher octane rating of these fuels.

[[Kerosene]] engines typically use a compression ratio of 6.5 or lower. The [[petrol-paraffin engine]] version of the [[Ferguson TE20]] tractor had a compression ratio of 4.5:1 for operation on [[tractor vaporising oil]] with an [[octane rating]] between 55 and 70.<ref>{{cite web |title=Tractor Vaporising Oil |date=2005-04-18 |url=http://tractorbits.com/infofiles/TVO.asp |access-date=2014-08-10 |url-status=usurped |archive-url=https://web.archive.org/web/20071012012756/http://tractorbits.com/infofiles/TVO.asp |archive-date=October 12, 2007}}</ref>