10 CRC Engine Durability Study CRC Study of 8 engine models (2001-2009) Engines removed from vehicles o Tested for 500 hr on drive cycle intended to simulate 100,000 mi o Tested on E20, if failing, tested on E15, if failing tested on E0 o Statistical analysis assumed passing result for engines not tested Failure criteria: o E = Emissions during EOT FTP75 testing o D = Diagnostic Trouble Code detected at EOT o V = Valve clearance measurement on at least one valve out of OEM specification at EOT o C = Compression measurement on at least one cylinder out of OEM specification at EOT o L = Leakage measurement on at least one cylinder above 10% at EOT Drive cycle engine speeds are too low to rotate valves (<3500 rpm) No E10 control testing Older vehicles well beyond full useful life at EOT Use of dummy data in statistical analysis biases results and makes error bars artificially smaller Inappropriate use of leakdown, typical shop manual criterion is 20-25%
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