oly 9

Hi Um trying to figure how this works. Eflite has a motor in the 480 size rated 225 watts. Omega has a motor that weighs 72g compared to 87 for the E flite. The diameter and length are very close. The Omega is slightly smaller. They both are 1100 kv. Also this info is for 3 cells. The omega is rated for 425 watts. How can the motors be so close in size and weight and be rated so differently in watts. Can one manufacture be so different from another? Is this a quality or engineering issue or is it over rating their product.? Does anyone know? Thanks for the help.