I use shell rotella 15w 40w oil.

Good choice of oils Guys!:beerchug: Here is a bit of information; NAPA oil is produced by Ashland Oil company, the same company that makes Valvoline oil. Buy the NAPA oil. You are getting Valvoline oil at a cheaper price.:biggrin2:

Napa 30 weight in Kohler Magnum 18hp, 10w30 in Kohler Command 22hp.

I just put Castrol GTX 30w in my new to me 1000, and I also use alot of Pennzoil 30w in my tiller, push mower, etc., although the Castrol seems easier to find around here lately.

I read a comparison test done by a magazine, many years ago, on how well 20 or so major brand names of oil held their viscosity after time and usage. Castrol and Pennzoil were 1st and 2nd place.

I don't recall what other brands were tested, and if those same results would be found today or not, but I have had good luck with both for many years. I think the more important things to consider are changing oil often, and not mixing matching different viscosities / brands.

Josh P

I prefer valvoline in all my motors, someone mentioned that pennzoil was a good oil....I strongly disagree. I have rebuilt many SB chevy engines over the years, when tearing one down for a rebuild it was not hard to tell the ones that had been using pennzoil, the amount of sludge in those motors is incredible. I have seen them so bad that the valve covers were completely packed with sludge, only enough room left in there for the valve train componets to move. Maybe alot of it was caused by poor maintainance, maybe just the nature of the beast, I am not sure, but I chose not to use it from my past experiences with it. However, if you have one that has been running pennzoil, I recommend to keep using until it gets rebuilt, if you switch to another brand, that has more detergent additives in it, it will break loose alot of that sludge and possibly cause an engine failure.

I imagine that alot of the problems I have seen are mostly due to neglect, however, I have never disassembled a motor using valvoline that had much more than minor deposits in it, in fact most were extremely clean inside.

I use Kohler 30 w in all my small engines. Bit more expensive but my local small guy swears by it. Been using it for years with no complaints. And he sells it me at cost.