is it correct oil?

Originally Posted by Well Oiled

SF and SG are indications of the oil quality, as defined by API (American Petroleum Institute). The S stands for Spark ignition (petrol engine). There are 'C' specifications for Compression ignition (diesel). Somewhere on the can will be a list of specifications that the oil meets.

The F and G are the quality level. Each time the spec is revised and improved it goes up a letter, so SG is a more recent and higher performance spec than SF, but they are both old specs. The latest is SM. If the second letter on your can is higher than G it will be fine as the later specs cover the requirements of the earlier ones.

Hope that helps Keith

OK. Got it. Thank you!