I understand viscosity index and oil weights (i work at an oil change shop). I have used 15w40 and 20w50 in ea82's. Currently, i am running Mobil high mileage 10w30 in the 96 Impreza (semi-syn, 5000 mi) and Mobil 1 high mileage 10w30 in my 86 3door (ej22 phase 2, full syn 10,000 mi) I am considering a 40 wt in the Impreza my next oil change, considering mobil1 0w40 full syn (as it will be winter with 0 degree weather.
But all that aside, i am wondering what was the factory fill oil in ea81 and ea82's when new. I know for sure that late model phase 2 engines came with 5w30 'energy conserving' oil from the factory to meet fuel economy standards for USDM, although the 'not recommended' stipulations exist in the owners manual, and the tech manuals at work, as well as listings for 5w30, 10w30, 10w40,, 30, 40, 50, 15w40, 20w50 are options based on temperature ranges.s. Based on that, and in my personal and professional opinion, 5w30 is only appropriate for temperatures consistently below 32-61 degrees F.
But for engines prior to 2000, 1995, before current economy standards, i am wondering what came in the box at the time of manufacture for EA engines. T^his would be before ISLAC GF 3 specs, and before API SJ, SI, SL specs. Current specs are ISLAC GF5 and API SN. Late model FA engines for 2013 and later call for 0w20 and 0w30 oil, as do most Toyota and Honda, and GM with 5w30 with 0w30 as winter option
Edited by MilesFox, 17 July 2014 - 11:14 PM.