... BUS Engines piston rings. United Material Piston Rings: for M.A.N. Engines Compression Ring | Intermediate Ring | Oil ... used for this purpose. Application:Piston rings set for M.A.N. heavy trucks & buses engine.Engine Models ... D 8614 M , D 9532 M , 2 BNM/S , D 0022 M 161 , D 0024 M 220/221 , D 0026 M 1/2 ... DO824 Euro II, I , DO826 Euro II, I , D2146 M , D2156, HMXU , D 2356HM2/HM9/HM10/HMN2/HMX , D2555M ...