Question: is simba bigger than mufasa?
Answer: simba struggled with an aging scar at the end. mufasa was clearly the stronger lion. @wolfrazer: This. If you compare Mufasa's size to Scar's, and then Simba's size to Kovu's who himself has a similar build to Simba in the first Lion King, Simba could very well be as big, if not bigger, than Mufasa in the sequel.