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Discussion Starter · #1 ·
The owners manual recommends 15w-40 but i hear of a lot of dealerships/lube shops using 5w-40, I guess it depends on your climate???

Chris
 

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5W-40 typically gives better startups, especially when cold. Just flows better cold. Now that Dino oil. Synthetics are even better flow cold. Only downside to running a 5W40 compared to a 15W40 is there are more thickening additives in teh oil to make that 5 weight act like a 40 weight.
 

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If I was running dino, I would be using the 5W-40 myself for my climate. If AMSOIL had a 5W-40 with a TBN of 12, I'd be using that as well:)
 

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Yup. I run Amsoil 5W30 in my cummins, but I reccomend the Dmax guys stay with the 40wight oils. After seeing the oil pressure and overheating problems the select few LLY's had, I would hate to risk lowering the oil pressure and more.
 

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A lot of people here in Alaska are using the rotella from shell or the amsoil. Not sure what type but I can find out.
 

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Follow the owners manual recommendations.
 
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