an intake system of engine comprises an intake pipe , an air intake manifold , and an auxiliary intake assembly disposed on the intake pipe and located before the air intake manifold of an engine . the auxiliary intake assembly comprises an auxiliary air inlet passage , an auxiliary air outlet passage , and a central passage . air enters through the auxiliary air inlet passage , comes out from the auxiliary air outlet passage and enters the central passage , so as to be mixed with air from the intake pipe . the present invention further relates to an engine intake system , comprising an electronic booster located upstream of the air intake manifold of an engine . an air flow enters from an air inlet , flows out from an air outlet , is mixed with air that flows through the intake pipe , and then is inhaled into a cylinder of the engine . the present invention further relates to a engines comprising the above intake systems . these intake systems and engines can effectively reduce discharge , reduce fuel consumption , improve engine efficiency , improve a low - speed torque feature of the engines , and improve a low temperature cold start effect of the engines .