I like running top of the line oil in my mower. Why? Because it only takes half a qt, and has no filter, and I want to maximize engine life, so why not? Anyways, I'm debating on trying Redline or Motul, but I'm curious whether this is wise considering that my engine has a plastic camshaft, and I've read that plastics and esters may not play well together. Engine is a Briggs Pro 7.75. I haven't analyzed the oil or anything, but just based on what the oil looked like at the end of the year, my ranking so far is
1- Valvoline VR1 Synthetic 10w30
2- Motorcraft 5w40 Synthetic
3- M1 TDT 5w40 Synthetic.
4- RP SN 10w30 (may be biased result because it was purple to start, but it seemed too thin also. Like a 20w)
The VR1 stayed clean significantly longer than the others. I know that's not scientific, but this began as a brand new engine and has had synthetic since breakin and yearly changes, so I very much doubt it's "because the others cleaned better." The engine sparkles inside, there is nothing to clean. It could be that the engine is only now 100% broken in, and was letting more past the rings the first couple years. I have a small yard, so it maybe gets 60 hours a year. If it continues to keep oil clean longer, I may re run some of the earlier oils and see if there is a change. It's just for fun, my way of being a nerd. (One of them anyways haha) I don't plan to do analysis, but I will be trying the standout oils in my 1959 John Deere 530 gas tractor, so maybe that I will analyze. I don't think even this site has many if any analysis records for one of those!