running 0-40W oil
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I’ve been reading through this "oil war" and wanted to throw my 2 cents in, and my personal take based on the weather where i live is that I wouldn’t move away from the 0w rating ( I use Motul 8100 Eco-lite 100% Sythetic)
My logic is that the absolute worst part of an engine's life and where the most damage is taken is at cold startup. The 0W is what protects those critical components in those first few seconds before the oil is fully flowing. Even if you don’t live in the Arctic, a 0W reaches the top of the engine significantly faster than a 5W or 10W, and in a V8 with this much complexity, I want that lubrication immediately.
That said, I totally get what ASE and BenCSVT are saying about the operating weight (the second number) when it comes to towing or extreme heat. If I were in the Southwest towing a heavy trailer, I’d probably meet in the middle with a 0W-30 or 0W-40. That way, you keep the superior cold-start protection of the 0W that I value so much, but you still get the thicker oil film (MOFT) at operating temp to protect the bearings under load.
It seems like the 0W-40 is the "best of both worlds" if you want to follow the non-US manual's advice for heavy duty while still protecting the engine during the most vulnerable part of its cycle.
My logic is that the absolute worst part of an engine's life and where the most damage is taken is at cold startup. The 0W is what protects those critical components in those first few seconds before the oil is fully flowing. Even if you don’t live in the Arctic, a 0W reaches the top of the engine significantly faster than a 5W or 10W, and in a V8 with this much complexity, I want that lubrication immediately.
That said, I totally get what ASE and BenCSVT are saying about the operating weight (the second number) when it comes to towing or extreme heat. If I were in the Southwest towing a heavy trailer, I’d probably meet in the middle with a 0W-30 or 0W-40. That way, you keep the superior cold-start protection of the 0W that I value so much, but you still get the thicker oil film (MOFT) at operating temp to protect the bearings under load.
It seems like the 0W-40 is the "best of both worlds" if you want to follow the non-US manual's advice for heavy duty while still protecting the engine during the most vulnerable part of its cycle.
The bigger issues I personally face when going with different oil grade is understanding and relaying that not all oils in a given range are the same, as the oil grade certification (ie two oils rated for 0w20 might fall at different points in the winter grade or sae grade and target different things like high temp high sheer ) is a range rather then a fixed weight number.
Some companies like redline make oils that really outclass the rest with a hths of 2.9 for a 0w20. Which is great (5w30/40s start at 3/3.5) and if you feel like 0w20 is all you want to run, that is the best. On the flip side, if you look at a penzoil platinums 5w30 offerings their hths tends to skew just right at the low end of 5w30, and uoa seems to indicate that sheer prone motors, drop the oil into 5w20 territory
Last edited by Framestead; Mar 6, 2026 at 06:36 AM.
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Watch this video and decide…
Discussed already in this thread: https://www.clublexus.com/forums/gx-...s-0w-20-a.html
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Joined: Jan 2025
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Watch this video and decide…
https://youtu.be/uAx5NcPo4hE?si=yGNATI0sZcx4r3VH
https://youtu.be/uAx5NcPo4hE?si=yGNATI0sZcx4r3VH
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Eliaquim
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Sep 24, 2014 01:25 PM