Iran is located at the high altitude region and has a diverse four season climate. The temperature difference of two locations at the same time reaches to 50° C. Therefore, the modern direct injection turbocharged engines are highly affected at this condition. This paper deals with the effects of temperature and pressure variations on the engine performance and fuel consumption of turbocharged gasoline direct injection engine. Ford ecoboost is selected for this study and the base experiments are performed at the sea level. At the next step, a comprehensive one-dimensional model of the engine is constructed in GT power and validated with experimental data. Validated model is implemented to investigate the effects of ambient air variations on the engine performance and fuel consumption. The simulations revealed that low end torque is not highly affected by the temperature increase due to the turbocharging compensation while engine torque is significantly dropped at high engine speeds in the elevated temperatures. At constant air temperature, brake specific fuel consumption is decreased for higher intake pressure up to 3000 rpm and does not change up to 3500 rpm.