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Vehicle Octane Number Requirement versus Altitude - Another Look
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English
Abstract
Historically, vehicle octane requirements decrease with increasing altitude due to the effect of changing barometric pressure on induction and ignition management system function. Recent advances in engine technology designed to reduce emissions and improve fuel economy of vehicles at high altitudes could result in minimal octane requirement change with changing altitude. In order to confirm the effect of these technology changes, Petro-Canada determined the octane requirements of twenty 1987-88 model cars and light trucks at high and low altitude locations. Seventeen of these were equipped with altitude compensation sensors. Contrary to previously published data, we found that the octane requirements of the 17 compensated vehicles were reduced, on average, by 0.5 (R+M)/2 per 1000 ft, increase in altitude. Although we expect that octane demand in high altitude areas will rise as the penetration of these vehicles progresses, the magnitude of the increase is not as great as previously estimated.
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Citation
Steckle, W., "Vehicle Octane Number Requirement versus Altitude - Another Look," SAE Technical Paper 892035, 1989, https://doi.org/10.4271/892035.Also In
References
- CRC Report No. 500 “1977 CRC Altitude Program” Feb 1979 Co-ordinating Research Council Atlanta
- CRC Report No, 523 “1981 CRC Altitude Program” Dec 1981 Co-ordinating Research Council Atlanta
- Callison J.C. “Octane Number Requirements of Vehicles at High Altitude” SAE Paper No. 872160 , Fuels & Lubricants Mtg. Toronto
- Minutes, CRC Octane Technology and Test Procedures Group Feb 25 1987 Detroit
- Minutes, CRC Octane Technology and Test Procedures Group Nov 4 1987 Toronto
- Mitchell Manuals for the Automotive Professional, Computerized Engine Controls
- CRC Designation E-15-88, “Technique for Determination of Octane NumberRequirements of Light-Duty Vehicles” Sept 1987 Co-ordinating Research Council Atlanta