Mark S. had asked me for some performance numbers on my RV-8 at more typical power settings than I normally use since I usually fly at economy settings.   Being an efficiency nut as well as the psychological effect of imagining a $50.00 bill going out the exhaust every hour is the reason, not any concern about the health of the engine.    I usually average only 5 - 6 GPH on a local area recreational flight at speeds around 130.   Thought I'd share the results of the trial run I did for Mark with the group.


 Went on a New Year's Eve flight and tried higher power settings at close to the conditions you gave me.   I have a fixed pitch prop and don't like to cruise at engine speeds more than about 6000 so had to modify the settings to keep them in that range.  (Mark had asked about performance at around 15 gph)   One other interesting thing  I noticed was that the OAT kept increasing the faster I went.   When I slowed down (at same altitude) the OAT measured 6 degrees lower.   My OAT sensor is located in the diffuser for the radiator but not in line of sight of the core.  I don't know if the change was due to rad heat finding it's way to the sensor or the result of compressing the air in front of the rad.

Altitude 6500
OAT  64
IAS 191 MPH
TAS (calculated) 214 MPH
GPS 4 way average - 212 MPH
MP  18.7" Hg
GPH  12.7
Engine RPM  6100

Tracy

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