Method for estimating the temperature of exhaust gas

The method involves determining an inlet temperature (T2) of exhaust gas entering a combustion chamber (21), and determining total amount of fuel injected into the combustion chamber (20). Temperature (T3) of the exhaust gas is estimated (22) from the inlet temperature and the total amount of injected fuel, where the temperature of the exhaust gas is estimated based on a relation logarithmic curve between a ratio of the temperature of the exhaust gas by the inlet temperature and the total amount of injected fuel. Independent claims are also included for the following: (1) an estimator for estimating temperature of exhaust gas produced by an internal combustion engine (2) a vehicle.