This Technical Report lays down the results of a study on the field correlation of the different cold operability (cold flow and cloud point) test results in relation to actual fuel performance in engines in real world cold conditions (below the fuel's cloud point). For this work historical data on both manual and automatic tests and on old (1988), current and future engine concepts have been used. Real market distillate fuels and Fatty Acid Methyl Esters (FAME), plus common blends thereof, have been investigated.