20/50 if you look in your owners manual covers a wide range of temperatures. I would run 10-40 in winter living up north, but most def. not in summer.

Not sure who told you 20/50 clogs your cam oiler tubes with sludge, but the weight oil you run has absolutely nothing to do with sludge. How often you change it, how hot your engine runs...that has direct effect on sludge.

All of my cars run either 15/50 or 20/50 and I can promise you they are as clean as can be.

Jonathan

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Blue Ridge Mercedes
Jonathan Hodgman
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Enthusiast Service, Restoration & Tuning.
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