An engine core including turbine, compressor, and core shaft connecting the turbine to the compressor, wherein a compressor exit temperature has an average airflow; and a fan upstream including a plurality of fan blades extending from a hub, each fan blade having a leading and trailing edge, wherein a fan rotor entry temperature has an average airflow across the leading edge of each blade at cruise conditions and fan tip rotor exit temperature has an average temperature of airflow across a radially outer portion of each blade at the trailing edge cruise conditions. A fan tip temperature rise as: the ⁢ ⁢ fan ⁢ ⁢ tip ⁢ ⁢ rotor ⁢ ⁢ exit ⁢ ⁢ temperature the ⁢ ⁢ fan ⁢ ⁢ rotor ⁢ ⁢ entry ⁢ ⁢ temperature . A core temperature rise as: the ⁢ ⁢ compressor ⁢ ⁢ exit ⁢ ⁢ temperature the ⁢ ⁢ fan ⁢ ⁢ rotor ⁢ ⁢ entry ⁢ ⁢ temperature , A core to fan tip temperature rise ratio of: the ⁢ ⁢ core ⁢ ⁢ temperature ⁢ ⁢ rise the ⁢ ⁢ fan ⁢ ⁢ tip ⁢ ⁢ temperature ⁢ ⁢ rise is in the range from 2.845-3.8.