either SAE 30 OR 10W 30 OIL
The type of oil that is recommended for Kohler engines is 10W-30 Command Oil. SAE 30 Magnum Oil is also recommended for certain Kohler engines.
I am not sure what you are wanting to use the oil for. If it is for a lawn mower, most of them take either 10w30 or SAE 30. They are not the same oil. You will need to refer to your engine manufacturer for the oil required for your engine. Normally most Briggs and Stratton and Tecumseh engines use the SAE30 oil. While most Kohler engines use 10w30.
15W-40 is the generally recommended weight to use, while the API rating MUST be CJ-4 for 2008 and newer engines, while CI-4 can be used for 2007 and older engines. You MUST use diesel oil, as oil intended for gasoline engines is not intended to withstand the higher temperatures of diesel engines.
The manufacturer recommends that you use 10W-30 weight oil. 10 W-40 weight oil can be used in high mileage engines.
If it has a Briggs and Stratton engine you need SAE30. If it is a Kohler it uses 10W30.
Most use 30Wt, though a Kohler Command wants 10-30 to run quietly.
Oil is oil period. You need to know "What viscoisity(weight) oil to use in the motorcycle?" These engines rev high and the right weight oil is extremely important.
15W-40 tends to be a "default" for diesel engines, but your operating environment also affects the ideal oil weight.
The manufacturer recommends that you use 10W-30 weight motor oil in your 2002 BMW 530 diesel. You can use a 10 W-40 weight motor oil in high mileage engines.
MTD Throrx engines are made by Kohler and Briggs and Stratton. Some Thorx small engines, for use in chainsaws, are made by Walburo Inc.
Most small engines use 30 weight non-detergent type.
An NPR diesel uses a 15w-40 weight oil in most applications. Gas engines use 10w-30.