It's a Briggs 26 hp. Water cooled heads. I had a thread awhile back about what intervals to change fluids. Many of the guys recommended a high zinc oil. Up till now I've been running NAPA synthetic 10w30
wonder who's oil NAPA has private labeled??
I'm reasonably sure it's more than fine.....and if Valvoline, it's the best ...period
also reasonably sure who ever makes it, the only change on the line are the bottles