Hi,
maximal effciency of 36% cannot be possible.
The "VTEC" Engine from Honda reach 215g/kWh at the best point!
File:Honda Insight 5mt.jpg - EcoModder
Heat engine - Wikipedia, the free encyclopedia
Burning temperatures about 2500°C and exhaust temperatures about 1000°C equals a maximal efficency of 54%.
Theoretical efficency for gasoline engine -> 63%
http://einrichtungen.ph.tum.de/T37/S...SS07/page3.pdf