It's probably just a way for the inefficient giant Sears to get rid of old stock and save a few cents in the process. I'd run a top grade oil or a synthetic.

The HONDA owners manual says SJ or later.

Here is a link that might be useful: GCV 160 manual

bill-kapaun

Thanks for the information on getting the engine manual. It gives me the information I needed. It really did not say what the API spec was for the oil that came with the machine. It just said it exceeded SG. However, the engine manual said SJ or later. Charles Ranheim

You can't really expect a manual FROM Honda to say anything about the oil Sears gave you.
In actual use, I doubt there would be ANY problem with SG.
There's a lot of engines out there that started their life with even more obsolete specs.

You need about 19 ounces anyway, and a 20 oz bottle is okay. I would use 10W30 in the new Honda in accordance with the manual. Anyway, your title says 'Honda oil in Craftsman mower', but your text says 'Craftsman oil in Honda engine'. Don't use the 30W oil in the mower. Buy the 20 oz bottles of 10W30 lawnmower oil.

I mostly use 10w-30 Mobil 1 in my 160cc Honda (GCV160.) Sometimes if I haven't had any around I've used the 5w-30 I have for the car. Mine is on its third season now. Still starts on the first pull and doesn't burn oil. I think my use is a little extreme compared to the average homeowner. So far this weekend I have filled the gas tank and run it dry four times and there probably isn't much left on that fifth tank. That's about nine hours of mowing.

One thing to watch on that engine is dust getting past the air cleaner. Some grease on the blue rubber sealing surface of the paper element seems to put a stop to that.