Normally I try to have enough oil around for two more oil changes and at least that for filters, but usually double that. In the cars I personally drive I keep an oil change and filter in the trunk for a 'just in case' situation. So I have 2 changes of ST 10w-30, a change and a half left of MaxLife and two changes of Delco 1300, plus some random bottles of GTX, Shell and RP 5w-30. I just bought another 2 cases of filters, so 12 filters of the car that I don't drive, 14 filters for my toy car and only 6 now for my beater. Do most here buy enough oil for only their upcoming change?