[en] Highlights: • FeCoCrNiW_0.3 high entropy alloy predicted and synthetized. • Slip bands around indentation marks could indicate alloy with stacking fault energy. • Addition of 5 at.% of C to FeCoCrNiW_0.3 produces hard carbides in HEA matrix. • Good resistance to oxidation in 700–900 °C range. • Hardness and scratch hardness compare well with conventional more expensive alloys. A new high entropy alloy (HEA) has been synthesized using a predictive method recently developed. The alloy performance is compared to that of a benchmark commercial alloys (Stellite®6) as wear resistance material for coating automotive engine valves. Using step by step predictive parameters the occurrence of an fcc solid solution with entropy of mixing higher than the conventional limit of 1.5 R (with R the gas constant) was singled out and verified in the FeCoCrNiW_0.3 composition. The as-cast ingot displays W segregation within the fcc grains as revealed by Scanning Electron Microscopy and X-ray Diffraction (XRD) patterns which were fitted by assuming the arc melted alloy contains two solid solutions. The segregation is eliminated by annealing at 1200 °C for 3 h. In these sample a (Co-Fe)₇W₆-type phase is found embedded in the solid solution matrix. Slip bands around indentation marks suggest low stacking fault energy of FeCoCrNiW_0.3. The high entropy alloy (HEA) has been hardened by adding 5 at.% C to form carbides inside the fcc matrix. Conventional hardness, scratch and oxidation resistance tests show that the alloy compares well with Co-based Stellite®6 being the content of the expensive and strategical elements halved with respect to it.