The used oil is contaminated from the combustion process, and while the engine may just be sitting in storage, condensation mixes with those contaminants, and form acids.
Well in that case, why not no oil?
2011 Sterling Gray Metallic 5.0 GT Premium, Manual, 3.73, Brembo, HIDs
Mods: 2010 AM GT500 wheels + Bridgestone Potenza S-04, GT500 axleback, MGW race spec, FRPP P springs, KONI STR.T struts/shocks, Steeda adj. panhard, BMR rear LCAs+relocation brackets