Guess I must be the odd man out here 'cause for a few $ and 1/2 qt of oil I can't imagine why one wouldn't change the oil in their genset at least once a year regardless of how little use the genset may see. Since oil is the life blood of any genset, regardless of whether that genset is a bargain basement or premium model, periodically throwing a few $ into an oil change seems obvious to me. Heck, I use more costly premium Mobil 1 synth instead of dino oil in my EU2000i but the small quantity required is hardly going to break the bank.