I suspect that the roots for both MRV (D-4684) & CCS (D-5293) cP testing dates back to the 'ol days when motor oil quality was not as good as today. I say this because of the different temperature standards applied to different cold weather grades for these standard cold pumpability tests: 0w-xx uses -40°C, 5w-xx uses -35°C, 10w-xx uses -30°C.
Pre API SH/SJ/SL, the advent highly refining oil, and hydrocracking producing grp 2/2+/3 base oils, many people in temperate climates used heavier weights in the summer and thinner weights in the winter. This common recurring opinion to use 10w-xx in the summer and 5w-xx (now 0w-xx) in the winter pops up here on BITOG regularly.
Due to the improved motor oil quality and characteristics with SM oils, 0w-xx, 5w-xx, or 10w-xx can be used year round by the majority of drivers; I have used 5w30 year round since 1988 (API SF/SH) and never had an engine or starting problem; northeast temps range from an annual week of near below zero temps in the winter to an annual week of 100°F in the summer (and summers in the southeast).
Cold cranking wear has been a concern for a number of years and it is time that one temperature is applied to all grades for accurate comparisons between the cold temperature grades; let's compare apples to apples. 0w's, 5w's and 10w' are now used by the majority of drivers for basically the same temperature range: -20°C (-4°F) to 35°C (95°F). The ASTM standards needs to be updated to one temperature for all grades. I say pick -35°C to give an extra bit of comfort for that rare cold snap. -40°C, -35°C, -30°C are all dang cold!
What's your opinion on MRV & CCS cP tests?
Pre API SH/SJ/SL, the advent highly refining oil, and hydrocracking producing grp 2/2+/3 base oils, many people in temperate climates used heavier weights in the summer and thinner weights in the winter. This common recurring opinion to use 10w-xx in the summer and 5w-xx (now 0w-xx) in the winter pops up here on BITOG regularly.
Due to the improved motor oil quality and characteristics with SM oils, 0w-xx, 5w-xx, or 10w-xx can be used year round by the majority of drivers; I have used 5w30 year round since 1988 (API SF/SH) and never had an engine or starting problem; northeast temps range from an annual week of near below zero temps in the winter to an annual week of 100°F in the summer (and summers in the southeast).
Cold cranking wear has been a concern for a number of years and it is time that one temperature is applied to all grades for accurate comparisons between the cold temperature grades; let's compare apples to apples. 0w's, 5w's and 10w' are now used by the majority of drivers for basically the same temperature range: -20°C (-4°F) to 35°C (95°F). The ASTM standards needs to be updated to one temperature for all grades. I say pick -35°C to give an extra bit of comfort for that rare cold snap. -40°C, -35°C, -30°C are all dang cold!
What's your opinion on MRV & CCS cP tests?
