The present invention relates to the technological field of cast iron alloys for automotive and similar applications. Problem to be solved: Presently, structural parts of internal combustion engines are made of gray cast iron alloys that rarely have a tensile strength limit range greater than 350 MPa or vermicular cast iron alloys that do not remain stable at high temperatures. Solution of the problem: It is disclosed a vermicular cast iron alloy that, due to the addition of amounts of Molybdenum, Copper and Tin, with Hot Resistance Factor from 0.5 to 1.7% (HRF=3×(% Mo)+1×(% Sn)+0.25×(% Cu)) achieves a tensile strength limit of 500 to 550 MPa at room temperature and up to 300° C., and a tensile strength limit of 430 to 450 MPa at 400° C.