Originally Posted By: RF Overlord
Remember, too, that the most popular grades of that time were 10W-40 and 20W-50, both of which had boatloads of VIIs adding to the problem.
I recall something about a bulletin from GM advising against the use of 10W-40 in some of their engines as it caused the ring packs to get gummed up...anyone else remember this?
I remember it.
In the oil that had the huge viscosity differences, like 10W-40, 20W-50 and 10W-50, it was explained to me that the additives would cause the most sludge and buildup.
In other words, they were saying to use an oil that had a narrower viscosity range, like a 10w30 or a straight 30W so that there would be less buildup.
I was real hard to get my dad off of 10W-40.
Remember, too, that the most popular grades of that time were 10W-40 and 20W-50, both of which had boatloads of VIIs adding to the problem.
I recall something about a bulletin from GM advising against the use of 10W-40 in some of their engines as it caused the ring packs to get gummed up...anyone else remember this?
I remember it.
In the oil that had the huge viscosity differences, like 10W-40, 20W-50 and 10W-50, it was explained to me that the additives would cause the most sludge and buildup.
In other words, they were saying to use an oil that had a narrower viscosity range, like a 10w30 or a straight 30W so that there would be less buildup.
I was real hard to get my dad off of 10W-40.
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