I think it probably makes sense to just go synthetic and forget about it. Since Briggs changed their small engine recommendations to 5-30 (or 10-30 can’t remember without checking) synthetic, I’m in the process of just using it year round in my small engines and not have to worry about weather changes.
I have no complaints about the 0W-30 that is required in the Sienna. I have never had to add oil between changes. As I posted earlier, I am going to test synthetic 10W-30 in my 23 year old lawnmower which I use in the summer and have. been using straight 30 weight. The engine uses oil so I am anxious to see if the oil consumption is less with the synthetic. Since the synthetic was $2.79 and less than $1 more than what I had been using, I havr nothing to lose even if the engine blows.
I have been using 10W-30 synthetic in my mower and trimmer and they’ve never run better.
@oblivion I am sorry to hear that the 10W-30 synthetic made your small engines run better. I was secretly hoping this 10W-30 synthetic oil would cause the engine to blow on my old lawnmower and get me out of mowing for a while.
Who’s to know if you accidentally forgot to put oil in in the first place. We won’t tell and it would be interesting to see how long it would run.
@Bing. I do have one mower that I ran part of last season without oil. It didn’t seem to hurt the motor. Of course it is a rechargeable battery powered mower. My wife really likes to now and I don’t. However she has had 2 rotator cuff surgeries and 2 foot surgeries. I thought the battery powered mower would work for her, but it is heavier than the gasoline mower which is an 18" with a cast aluminum deck. I thought the battery .power mower would do the job since she,wouldn’t have to pull the starter rope. I really don’t want the complexity of a self propelled electric start, so maybe the synthetic oil will buy me another year.