Never mind. I got the good ole Google answer. Just to think how long I was wrong about oil weights. Who knew.

Valvoline VR1 Full Synthetic Racing Oil 20W50

The bigger the difference between the Winter designation and Summer like a 5W50 the more friction modifiers have to be put in . Friction modifiers turn to $hit and the oil suffers.

This guy can explain it better:

https://www.youtube.com/watch?v=E_iN_IJpSIU My most recent experience with Mystic and mobil 1 15W50 is that when I change the oil it comes out thin as water so I switched

I really liked the straight 50 weight Brad Penn I used this weekend, we`ll see what BlackStone labs will say about it after I get some more hours on it.

I'm thinking of trying some mystik 15-40 but still have a case or two of VR1 straight 50 to use up. Anybody running that 15-40 mystik?

Valvoline VR1 20-50 Full Synthetic , if its good enough for my JD-345 with the 60" deck and the liquid cooled Kawi 20hp thumper its good enough for the 540's :bunnydance::bunnydance:

Mild Thunders oil pressure with Mystic was down too.

^^ I reread that. Got it now. VR1 is where I'll stay

Yep. Fresh 15w50 Mystik. After a hard run, oil temp around 190ish, at idle, in gear, oil pressure was 20-25psi. Changed it out, for 20w50 VR1 Synthetic in that engine, same scenerio, oil pressure was 30-35psi.

I have those oil drain hoses that hook to my oil pans. Using my little jabsco drill pump, engines had been sitting for a week, I was able to suck out 9 quarts from the pan, in no time at all. Mystik was coming out like water. had not even 10 hours on it.

In Michigan it can on some mornings! :)

Appreciate you sharing that. Real world firsthand experience.