Small engine oil?

dodge man · 2026-03-27T16:58:09-0400

Not another oil thread! I did a search and didn’t see it addressed. What do people do for small engine oil? It used to be straight 30 weight was called for but that seems outdated these days. I found some small engine 10w-30 Walmart branded oil and bought a couple of quarts. Is just regular synthetic 10w-30 ok, that seems like what I’ll probably start using.

Edit, the stuff I got at Walmart is straight 30 weight.

mjonesnh · 2026-03-27T17:12:13-0400

dodge man said:
Not another oil thread! I did a search and didn’t see it addressed. What do people do for small engine oil? It used to be straight 30 weight was called for but that seems outdated these days. I found some small engine 10w-30 Walmart branded oil and bought a couple of quarts. Is just regular synthetic 10w-30 ok, that seems like what I’ll probably start using.

All my air cooled engines spec either 30w or 10w-30 conventional or 5w-30 synthetic with the exception of my Honda Rancher that says 10w-40. With that said I went to 1 oil for all the air cooled engines. Rotella T6 5w-40 years ago. Never a problem with this oil and easier starting in cold weather. In fact, just purchased a new inverter generator 3 weeks ago and after break- in of 5 hours I changed it to the Rotella T6. If I was using a gasoline rated oil I would probably go with 5w-30 or 10-30 synthetic, likely Mobil 1.

kevinj · 2026-03-27T17:15:54-0400

Mine all get the same 15w40 that goes in the tractors.

CloverKnollFarms · 2026-03-27T18:07:43-0400

Mine specs 20w-50 synthetic for summer temps

RandyT · 2026-03-27T18:13:32-0400

@dodge man Regular oil is fine and doesn't require synthetic. Lawnmower oil is formulated to operate at higher temps than regular auto oil, and also contains a higher zinc content due to the flat tappets.

nyone · 2026-03-27T19:32:36-0400

I have a Toyota that specs 0w20 oil, so I put that in. Any diesel gets 15w40. My suburban would be expensive to replace so it gets the 5w30 it wants and so every other engine i own gets 5w30. Generally gas engines especially small ones will be totally fine with 5w30.

For me the $2 synthetic costs its not worth stocking conventional for a few small engines. I typically like to keep about 2+ yrs of oil changes on hand for every vehicle. I own 14 things that have a seat and you can drive.