My trucks oil gauge just maxed out to 80.when on open road I floor the pedal and it goes to 0 then gradually moves to 80 and then fluctuates.

oil pressure switch may be bad,or you would have probably already blown the engine from FLOORING it! have the oil pressure checked with a gauge,and have the switch checked! that gauge is there for a good reason. i wouldn't be just flooring it,unless you just want to buy a new engine in case that is a correct reading!