Although modern engines often specify a Starburst oil rather than an API SM/SL/SJ-certified oil, Heavy Duty Engine Oil (HDEO) can sometimes be used in its place.  Starburst oils are passenger car engine oils that meet the latest ILSAC specification (currently ILSAC GF-4).  The main differences between HDEOs and Starburst Oils are maximum phosphorus levels and friction modifiers.  HDEOs are not limited to 800 ppm of phosphorus although API CJ-4 limits phosphorus to 1200 ppm.  Starburst oils have friction modifiers for better fuel economy (1-2% potential improvement) which HDEOs generally do not have.

If your car has a flat-tappet camshaft and no emission controls (catalytic converter & O2 sensor), then you should be using oils that contain enough phosphorus (in the form of ZDDP) to protect the valve train.  Any currently available HDEO contains more ZDDP than what is needed for OEM-style valve trains.  Aggressive aftermarket valve trains would probably be safer with CH-4 or CI-4 oils but there is more to an ideal engine oil than total ZDDP content.  If your car is equipped with a roller camshaft and full emission controls, you can also use the latest HDEO (currently CJ-4/SM), which should offer additional anti-wear additives to keep your engine from wearing prematurely.  HDEOs also contain additives to combat ring sticking that can sometimes be a problem on modern low-emission engines.  If your engine is not burning oil, the higher levels of phosphorus in an HDEO won't affect the emission system and should help to prevent it from burning oil in the future.

The following pages list HDEOs available in North America.  If the oil you are interested in trying is not your local store's shelf, you can order it from a distributor.  Engine oils with a certification equal to or lower than API CF are NOT listed.