I just used up a bottle of Pennzoil SAE30 from the early 90s in a mower that my parents found by the curb. SG rated, if memory serves. Also have an old bottle of Amoco SG rated SAE30 oil that I may use in a lawnmower someday. I found a bottle of SH rated Pennzoil at a KMart a couple of years ago that I bought to display on my shelf. Circa early 2000s, I believe?