7 Engine exhaust systems for trucks and busses, comprising pipes, selective catalyst reduction (SCR) units, collectors, clamps, diesel particulate filter (DPF) units; engine exhaust aftertreatment systems for trucks and busses, comprising pipes, collectors, selective catalyst reduction (SCR) units, catalyst tanks, mixing tubes, exhaust fluid injectors, diesel oxidation catalyst (DOC) units, diesel particulate filters (DPF); filters for trucks and busses, namely, fuel filters, air cleaners, oil filters; parts of internal combustion engines, hybrid engines, fuel cell powered engines, and electric motors for trucks and busses, namely, cylinder blocks, cylinder heads, crankshafts, flywheels, connecting rods, camshafts, fuel pumps, water pumps and fans, oil pumps, and radiators