Q: I've been checking my oil and it's still at fulll and the oil is still light brown. What are some key indicators that I need it changed?

Hello. Most of the indicators that the oil needs to be changed are not visible to the naked eye. Simply getting oil hot while driving down the highway will darken it. The road grit and engine wear "debris" is often measured in microns (1 millionth of a meter), microscope territory. The simplest guide for oil and filter changes is 3-5,000 miles for highway use. Much more often for off-road or extreme duty situations (heavily loaded trucks, racing applications, stop-and-go driving only). Oils also accumulate acids over repeated cold-hot-cold-hot cycles, which attack metal surfaces including bearing, cylinder walls, etc. Follow your manufacturers guidance for oil/filter service.