An improved exhaust gas recirculation cooler comprising: an elongated, hollow main body; first and second end plates (24, 26) coupled to opposing ends of said main body; and at least one cooler tube assembly coupled between said first and second end plates (24, 26), said at least one cooler tube assembly including at least one elongated tube member with a substantially oval cross-sectional shape and a fin sheet having first and second longitudinal ends, said fin sheet extending into at least a portion of said tube member, characterised by: said at least one tube member extending beyond at least one of said first and second ends of said fin sheet to describe an unoccupied oval tube region having at least a first convolution integrally formed therein, said first convolution defining a relatively flexible section of said at least one cooler tube assembly, said tube member and said fin sheet being restrainably bonded within a relatively rigid section of said at least one cooler tube assembly, separate from and integrated with said relatively flexible section of said at least one cooler tube assembly, wherein said relatively flexible section of said at least one cooler tube assembly displaces upon thermal expansion of said at least one cooler tube assembly, to limit mechanical stresses proximate said first and second end plates (24, 26). an elongated, hollow main body; first and second end plates (24, 26) coupled to opposing ends of said main body; and at least one cooler tube assembly coupled between said first and second end plates (24, 26), said at least one cooler tube assembly including at least one elongated tube member with a substantially oval cross-sectional shape and a fin sheet having first and second longitudinal ends, said fin sheet extending into at least a portion of said tube member, characterised by: said at least one tube member extending beyond at least one of said first and second ends of said fin sheet to describe an unoccupied oval tube region having at least a first convolution integrally formed therein, said first convolution defining a relatively flexible section of said at least one cooler tube assembly, said tube member and said fin sheet being restrainably bonded within a relatively rigid section of said at least one cooler tube assembly, separate from and integrated with said relatively flexible section of said at least one cooler tube assembly, wherein said relatively flexible section of said at least one cooler tube assembly displaces upon thermal expansion of said at least one cooler tube assembly, to limit mechanical stresses proximate said first and second end plates (24, 26). said at least one tube member extending beyond at least one of said first and second ends of said fin sheet to describe an unoccupied oval tube region having at least a first convolution integrally formed therein, said first convolution defining a relatively flexible section of said at least one cooler tube assembly, said tube member and said fin sheet being restrainably bonded within a relatively rigid section of said at least one cooler tube assembly, separate from and integrated with said relatively flexible section of said at least one cooler tube assembly, wherein said relatively flexible section of said at least one cooler tube assembly displaces upon thermal expansion of said at least one cooler tube assembly, to limit mechanical stresses proximate said first and second end plates (24, 26).