77 Lubricants Motor Oil SF 20W-50

Worth knowing

The codes here are the same as in Motor Oil SF 15W-40: API SF and CD, with no declared approvals or carmaker compliance. The two oils in the line differ in viscosity, 17.8 mm²/s against 13.6 at 100 °C and 153.4 mm²/s against 93.7 at 40 °C, and in base number, 7.3 mg KOH/g against 8.5; sulphated ash is 0.66 % in both. The cold-cranking figures cannot be compared directly: the CCS of this oil, 6,080 mPa·s, is given at -15 °C (the SAE J300 limit for 20W is 9,500 mPa·s), whereas the 15W-40’s is given at -20 °C.

The article on API class CD describes the diesel part of the designation as intended for both naturally aspirated and turbocharged engines, and the data sheet likewise speaks of engines with or without a turbocharger. However, API warns that CD is not suitable for most car diesels made after 1994; for petrol SF the corresponding date is earlier still, 1988. Apart from this oil, the brand’s only 20W-50 with API CD is Racing Oil Classic 20W-50, whose petrol codes differ: API SG and MS, plus claimed compliance with Ford M2C101-A, M2C101-B and M2C101-C.