For lubrication. Steel on steel would cause friction with would lead to heat which would cause seizing of parts and destroy the engine.
No, old oil can use synthetic engines
No. It is blended for gears not for engines.
Racing engines use Oil most of then 7 quarts or more, and they use racing oils like Torco, Redline or Lucas.
The gas engines use 5w20The diesel uses 15w40Any name brand oil is fine.The gas engines use 5w20The diesel uses 15w40Any name brand oil is fine.
Oil is used in cooking, greasing and also we can use in engines.
If you mean motor oil, yes.
oil and grease is used in vehicles to reduce friction.
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.
buses
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.
either SAE 30 OR 10W 30 OIL
No. You need a specialized engine for that. These engines can burn other oils too, like burnt motor oil, vegetable oil, etc.