Alco Synergie Synth 5W-40. Alco Synergie Synth 5W-40 is a high performance low friction oil of the new "Low SAP"-generation. It was designed on base of synthetic oils, and it is foreseen for passengercar engines with exhaust aftertreatment devices (catalytic converter, diesel particultate filter) and without. Due to its progressive conception it provides an extremely wide range of performances: