Measured operating-point identities
Engine Test-Point Calculator
Calculate brake power, brake-specific fuel consumption, brake thermal efficiency and BMEP from one consistent measured operating point. No rating or atmospheric correction is invented.
Calculated test point
These are dimensional identities for a measured brake test point, not proprietary empirical correlations. BSFC is fuel mass rate divided by brake power. The US EPA engine-test plan likewise describes BSFC as fuel consumption divided by engine power and bases brake work on measured dynamometer torque and speed.
The result is rejected if calculated brake power exceeds the supplied fuel-energy rate; that indicates inconsistent measurements, time bases or calorific-value basis rather than a valid efficiency.
ISO 3046-1:2002 remains the published edition as of this review and adds engine power/fuel/oil declaration and test-method requirements to ISO 15550. ISO lists it as due for revision; ISO/DIS 3046-1, edition 6 is under development and is not yet a published replacement.
ISO 15550:2016 is the current general framework for reference conditions, declared power/fuel/oil consumption and engine-power test methods. ISO 3046-3:2006 covers measurement techniques needed to compare measured values with manufacturer specifications.
COP, PRP, LTP and ESP are generating-set application/rating classifications associated with ISO 8528-1:2018. They are not universal multipliers that turn a calculated engine power into 1.0×, 1.1×, 1.2× or 1.3× power, so the former selector was removed.
Removed unsupported material: generic engine/fuel presets, fixed fuel heating values, stoichiometric air-flow estimates, universal diesel/gas tables, blanket altitude/temperature derating factors, “heat rejected” as fuel input minus brake power, and equal per-cylinder power.
