The global efforts to reduce CO2 emissions, as well as the restrictions on fleet fuel consumption, accelerate the development of efficient driving solutions. A promising approach is the use of methane, the main component of natural gas, because of a CO2 reduction of about 25 % according to the low carbon content. Furthermore, methane provides, due to the high knock resistance, the possibility for efficiency raising measures. In the present work, the consequent adaption of a gasoline turbocharged three cylinder engine with 658 cm³ and four valves per cylinder for the use of natural gas is evaluated. Therefore, a stoichiometric combustion process with natural gas direct injection is implemented. With respect to the high knock resistance, pistons with an increased compression ratio of 13,6 and higher peak pressure stability as well as reinforced con rods are used. In addition, the variation of the intake valve timing allows the internal exhaust gas recirculation during part load and scavenging at wide open throttle operation. During part load, the engine can be de-throttled and mixture formation can be improved by intake synchronized injection. For a high LowEnd torque, the injection takes place after the intake valves close, eliminating the displacement effect of natural gas and causing an increased engine torque. In addition, a significant increase in torque is achieved by scavenging. Only raising the compression ratio shows a marginal advantage in fuel consumption due to increased wall heat and unburned fuel losses. Through a reduction of the compression ratio to 12,0, the combustion chamber shape is more favorable and presents the optimum for this engine. A modified intake camshaft design, with interlaced valve lift curves of the two intake valves, leads to the implementation of an Atkinson cycle, which creates significant fuel consumption improvement during part load and increased volumetric efficiency in full load operation. This results in an 8 % reduced fuel consumption by improved combustion process during the New European Driving Cycle on top of the 25 % CO2 savings due to the fuel properties. The methane slip is a big challenge for the exhaust gas aftertreatment of natural gas engines. The required catalyst temperature to reach the light-off point in comparison to gasoline is about 200C higher than for the stabile molecule methane. In slightly rich engine operation an increased methane conversion can be achieved at reduced temperatures, which, however, goes along with the formation of ammonia. One promising measure for fast achievement of the light-off temperature is the post injection during late combustion.