Cat C-7 diesel oil viscosity
I have a 2004 Cat C-7 in a 36' Meridian which I have been using Rotella 15W-40 oil in it since new 68,000 miles back. Seems I remember reading somewhere the thought was that 10W-30 was better for the...
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Modern 4 stroke engines just aren't that sensitive to very small variations in oil rated viscosity. The difference between a CJ rated 10W-30 and a 15W-40 is very small, and many oils could probably be rated either way, since the window for the rating is fairly wide. If I wanted to put the best oil in, I would pick a synthetic 5W-40 like Rotella T6, unless I was running in very cold ambient temps when I would pick a 0W-40 full synthetic. With a HEUI injection system most times it's more critical to change the oil on time.
Brian
Brian
