A muffler for an exhaust system of a gas combustion engine, which comprises a muffler body (14) connected to an exhaust pipe inlet (10a), an exhaust pipe outlet (11a) to the tailpipe connected to the muffler body (14), and adjacent baffles (23, 24) within the muffler body (14), characterized in that the exhaust pipe inlet (10a), the exhaust pipe outlet (11 a) and the adjacent baffles (23, 24) are in line without significant restriction to gas exhaust flow and having baffle openings (21, 22) and baffle louver openings (18b, 19b) to the central muffler chamber (17), whereby the central muffler chamber route (17) is generally a straight line from the exhaust inlet pipe (10a) to the exhaust pipe outlet (11a).