The Gaz Energy 
The Commercial Court, via “The Gaz Energy”  852 LMLN 2 case, established the meaning of “overperformance” in view of bunker/consumption savings. The court determined the proper meaning of “overperformance” as performance that was better than warranted. Specifically, the court considered a warranted term of about 40mt/day of IFO. The Court determined that the warranty indicated an allowable range of 38mt/day to 42mt/day IFO when applying 5% for the term “about.” The court held that an “overperformance” would be had if the vessel consumed less than 38mt/day IFO. A consumption between 38mt/day and 42mt/day fell within the allowable range and did not constitute an “overperformance.” In other words, if the vessel consumed less than 38mt/day IFO, then the vessel had “overperformed,” or saved on IFO consumption.
To summarize, “The Gaz Energy” established the method to be applied for assessing savings on consumption, provided that the governing charter party agreement does not stipulate a different methodology. “The Gaz Energy” established that a vessel has performed as warranted if it demonstrates a consumption between +/-5% of the warranted consumption. A rate of consumption less than the warranted consumption minus (-) 5% represents a savings.