Lubricant compositions containing molybdenum for reduced pre-ignition in hydrogen fueled engines

A method of reducing abnormal combustion events in a hydrogen fueled internal combustion engine (HICE) during operation of the engine comprising:

• a) providing to the hydrogen fueled internal combustion engine a lubricating oil composition comprising or resulting from the admixing of:
• i) a base oil having a viscosity KV100 of less than or equal to 12 cSt and included at greater than 50 wt. % of the composition and comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;
• ii) at least one overbased metal containing detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and included at a treat level to deliver between 100 to 5000 ppm by weight of total metal and between 0.15 wt. % to 8.0 wt. % of total soap to the composition;
• iii) at least one molybdenum containing compound included at a treat level to deliver between 20 to 2000 ppm by weight of total molybdenum to the composition;
• and
• iv) the lubricating oil composition having a total sulfated ash of less than or equal to 2.0 wt. %, a total phosphorus level of less than or equal to 0.120 wt. %, and a SAE viscosity grade of 25W-X, 20W-X, 15W-X, 10W-X, 5W-X or OW-X, where X represents any one of 8, 12, 16, 20, 30, 40, 50 or 60;
• and
• b) providing a fuel comprising hydrogen to the hydrogen fueled internal combustion engine;
• and
• c) combusting the fuel in the hydrogen fueled internal combustion engine;
• and
• wherein the hydrogen fueled internal combustion engine (HICE) operates at a BMEP ranging from 12 bar to 18 bar and at an air:fuel ratio (AFR) from 1:1 to 3:1;
• and wherein the fuel supplied to the hydrogen fueled internal combustion engine comprises at least 90 mass % hydrogen.