Tom F&L GoR
Enthusiast
I was doing a little research and came across this chart of Mobil engine oil products. I am not promoting Mobil; I just think this illustrates a point well.
Oils used to have ~1200 ppm phosphorus (P) as a normal treat rate but the OEMs claimed it harmed catalytic converters. Every other new API category has lowered the allowed level in those oils that the OEMs generally use as factory fill and wish to be "fuel efficient." Therefore the P limit really only applies to the ILSAC starburst oils (symbol on front of bottle) that claim GF-4, which are SAE 10W30 and lower grades.
API SG and SH were 1200ppm, SJ and SL were 1000ppm, SM is 800ppm, and the next category yet to be named is planned for a fall 2010 introduction. It should have between 600 and 800 ppm P. The engine builder woes (wiping out flat tappet cams on break in) started with API SM 800 ppm P oils. I haven't heard of street engines with roller cams having problems. Look at the chart and here are some things you'll note:
0W40 is API SM, but 1000ppm P. That's because its not GF-4, a general OEM factory fill oil that needed to meet fuel economy targets.
The 15W50 has apparently been reintroduced and Mobil makes claims to use this oil in older engines.
The diesel 5W40 (as I have advocated) has 1100 ppm P. And lots of other good stuff.
The high mileage oils have more than 800 ppm P, and therefore are "only" API SL instead of most current SM. But they meet Euro requirements, so I suspect this is really a current European formulation relabeled as high mileage oil in the US.
The M1 Racing 4T oil is a motorcycle oil. Motorcycles still don't have catalytic converters, nor do they have friction modifiers. They have generally stayed at the API SH performance level.
The racing or motorcycle oils would make for good break-in oils if you didn't mind paying synthetic oil prices.
In the future you can assume 1000ppm P oils are good wear protection, probably fine for breakin, even street engine track days, racing, etc. 800ppm P oils are OK, questionable for breakin, good for roller cam engines. I don't want to be labeled as the type that needed leaded gasoline because all engines will die on unleaded, but I have reservations about oils with less than 800 ppm P.
The list may change, but it is a good summary right from the horse's mouth.
http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf
Oils used to have ~1200 ppm phosphorus (P) as a normal treat rate but the OEMs claimed it harmed catalytic converters. Every other new API category has lowered the allowed level in those oils that the OEMs generally use as factory fill and wish to be "fuel efficient." Therefore the P limit really only applies to the ILSAC starburst oils (symbol on front of bottle) that claim GF-4, which are SAE 10W30 and lower grades.
API SG and SH were 1200ppm, SJ and SL were 1000ppm, SM is 800ppm, and the next category yet to be named is planned for a fall 2010 introduction. It should have between 600 and 800 ppm P. The engine builder woes (wiping out flat tappet cams on break in) started with API SM 800 ppm P oils. I haven't heard of street engines with roller cams having problems. Look at the chart and here are some things you'll note:
0W40 is API SM, but 1000ppm P. That's because its not GF-4, a general OEM factory fill oil that needed to meet fuel economy targets.
The 15W50 has apparently been reintroduced and Mobil makes claims to use this oil in older engines.
The diesel 5W40 (as I have advocated) has 1100 ppm P. And lots of other good stuff.
The high mileage oils have more than 800 ppm P, and therefore are "only" API SL instead of most current SM. But they meet Euro requirements, so I suspect this is really a current European formulation relabeled as high mileage oil in the US.
The M1 Racing 4T oil is a motorcycle oil. Motorcycles still don't have catalytic converters, nor do they have friction modifiers. They have generally stayed at the API SH performance level.
The racing or motorcycle oils would make for good break-in oils if you didn't mind paying synthetic oil prices.
In the future you can assume 1000ppm P oils are good wear protection, probably fine for breakin, even street engine track days, racing, etc. 800ppm P oils are OK, questionable for breakin, good for roller cam engines. I don't want to be labeled as the type that needed leaded gasoline because all engines will die on unleaded, but I have reservations about oils with less than 800 ppm P.
The list may change, but it is a good summary right from the horse's mouth.
http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf
