Found this in one of the articles on the CIMAC website:
Sounds great... but 2% of BSFC is an infinitesimally small number, since a 2% reduction in BSFC on a typical high-performance engine would be like saying you reduced the initial BSFC of .5000 lb/(hp⋅h) * .98 = .4900 lb/(hp⋅h).
CIMAC said:Experiments were completed using a fuel economy test protocol that was defined, consisting of repeating six speed/load operating conditions. An automated dynamometer control system was implemented to ensure repeatability of the test procedure. Preliminary testing indicated that the coolant, oil, and exhaust temperatures reach a steady state within 5 minutes of changing operating conditions. The system oil viscosity was found to have a significant impact on friction, with a reduction in viscosity from SAE 30 to SAE 20 resulting in over 6% reduction in friction mean effective pressure (FMEP) and over a 2% reduction in brake-specific fuel consumption (BSFC). Chemistry effects were also evident in the system and cylinder oils. Repeatability comparisons between the individual repetitions of each operating condition were used to ensure that results are statistically valid. For the initial cylinder oil viscosity experiments, observed changes were within the established/normal repeatability; ongoing experiments will determine whether improvements in boundary condition control will enable cylinder friction changes of this magnitude to be measured on this engine platform.
Sounds great... but 2% of BSFC is an infinitesimally small number, since a 2% reduction in BSFC on a typical high-performance engine would be like saying you reduced the initial BSFC of .5000 lb/(hp⋅h) * .98 = .4900 lb/(hp⋅h).