The high quality of the bases and the high percentage of additives used in eni i-Sigma performance E7 15W-40 allow to significantly extend the service period. The detergent and dispersing properties, attested by the overcoming in particular of the ACEA E7 / E5 and API CI-4 / CH-4 specifications, make eni i-Sigma performance E7 15W-40 able to keep the pistons exceptionally clean and keep the solid combustion products thus preventing the formation of dangerous deposits in the crankcase. The antioxidant, anti-rust and anti-wear properties of eni i-Sigma performance E7 15W-40 are able to meet the needs deriving from heavy duty service and the prolonged changeover period foreseen for this lubricant. In fact, they effectively hinder oxidation and the consequent change in oil viscosity, protect a.