V8_Fan

I have both the 2UZ (engine for the LX/GX470 and 98-07 toyota landcruiser) and 3UZ (LS430). The engines are the same design other than a larger bore and slightly longer stroke for the 2UZ. Overseas including in Japan, a 10w30 weight oil is recommended while in the US, 5w30 is recommended. As you all know, a 10w30 mineral-based oil has substantially higher viscosity than a 5w30. The reason the 5w30 must be recommended and used by dealerships/automakers in the US is the automakers use the thinner 5w30 oil in federal emissions/fuel economy tests, and they are required to recommend and sell the same grade of oil used in those tests. The 5w30 weight is primarily to manipulate the emissions/fuel economy numbers (much thinner than 10w30, so the engine warms up quicker). Overseas (at least for the 2UZ), engine longevity is the primary concern rather than air pollution. Also, parts like the engine oil filters are different overseas. They use the resin-core (looks like a dense felt) in the 2UZ/3UZ oil filters while N.American engines use the standard paper (we used to get the "good" resin-core made-in-Japan factory filter, but those became too expensive and the cheaper Thai-made paper filters are now what's available). Yes, they still meet specs, but keep in mind that overseas (I mean places like the Mid-East, Australia, Africa), people keep their cars for a lot longer than here so the emphasis is on longevity, whereas here, the emphasis is on keeping down costs and meeting federal regs. I've owned and have been driving toyotas for the last 26 years (mostly doing maintenance myself), and have never used a 5w30 weight oil (mostly 10w40 mineral-based oils w/ a 3K mi OCI with a shift to M1 Delvac 5w40 and 0w40 synthetics over the last 10 yrs w/ 8K mi OCI's). No issues yet. Personally, I like the Delvac 5w40 the best (used by commercial trucking companies), but it got too pricey...0w40 is about as good but cheaper, and much better than the Walmart M1's.

jbraswell

Actually the Mobil Super (non syn) 10w-30 oil is thinner at 100C (10.5) than either the Mobil 1 (syn) 5w-30 (11.0) or 0w-30 (10.9).
But your points have no logic since Toyota is leading the auto market with it's 0w-20 oil. Obviously Toyota believes 0w oils are superior.

I do agree with you about the filter. I only use the 90915-20004 in both my 2UZ and 3UZ oil changes.