Saw I can get this stuff at Home Depot for $6/quart. Is this stuff any good? Ran some GTX 10w30 with some MMO for a short time in my new-to-me John Deere tractor which was burning some oil, and the smoke screen seems to have stopped. So, go with this stuff, or spring for Rotella T6? I'm sure the JD SL-rated oil is probably still better than when the tractor was new 28 years ago.