The effect of fuel composition and engine deposits on emissions from a spark ignition engine

Stanley L. Bower, Thomas Litzinger, Vincent Frottier

Research output: Contribution to conferencePaperpeer-review

11 Scopus citations


Chemically defined binary fuel mixtures of iso-octane (baseline fuel), toluene, methyl tertiary butyl ether (MTBE), and di-isobutylene (DIB) have been run in a production spark ignition engine at various speed/load conditions, with the engine in a clean (deposit-free) and deposited state. Pre-catalyst exhaust gases were analyzed for NOx, total unburned hydrocarbons (UHC), and speciated unburned hydrocarbon concentrations. As toluene was added to the baseline fuel, NOx concentrations increased but total unburned hydrocarbons remained constant. Total unburned hydrocarbons and NOx were unaffected by MTBE. DIB reduced total unburned hydrocarbon emissions but had little effect on NOx. Pure iso-octane produced seven major unburned hydrocarbon species. All the fuels when added to iso-octane resulted in changes in the existing species as well as the production of new ones. The major hydrocarbon species observed in the exhaust were consistent with current intermediate temperature oxidation mechanisms for the fuels studied. NO x concentrations increased substantially when the test fuels were repeated in the engine after deposits were formed; however, total and speciated unburned hydrocarbons were not significantly affected.

Original languageEnglish (US)
StatePublished - Dec 1 1993
EventFall Fuels and Lubricants Meeting and Exposition - Philadelphia, PA, United States
Duration: Oct 18 1993Oct 21 1993


OtherFall Fuels and Lubricants Meeting and Exposition
Country/TerritoryUnited States
CityPhiladelphia, PA

All Science Journal Classification (ASJC) codes

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering


Dive into the research topics of 'The effect of fuel composition and engine deposits on emissions from a spark ignition engine'. Together they form a unique fingerprint.

Cite this