[FJtest]

I don't know of the weights correlate to what we have in the US, but you're nuts to use a 40 weight in a motor designed for 20. There's reasons they use 20 - and you will void your warranty by using it if something goes wrong. Don't second guess the Toyota engineers. Smaller passages in newer blocks require thinner oil.
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A case of severe ignorance, wrong on literally all counts.

If you're skeptical of the much higher oil viscosities recommended by Toyota for the "rest of the world" FJs, using the same 1GR-FE engine as we get in the US but that DON'T need to meet the US fuel economy regulations, just read the oil viscosity recommendations made in the US Owner's Manual. Here's what Toyota says in the 2014 FJ manual (ESPECIALLY THE VERY LAST PARAGRAPH!!):

"Oil grade: ILSAC GF-5 multigrade engine oil
Recommended viscosity: SAE 0W-20

SAE 0W-20 is the best choice for good fuel economy and good starting in cold weather.
If SAE 0W-20 is not available, SAE 5W-20 oil may be used. However, it must be replaced
with SAE 0W-20 at the next oil change.

Oil viscosity (0W-20 is explained here as an example):
● The 0W in 0W-20 indicates the characteristic of the oil which allows cold startability. Oils with a lower value before the W allow for easier starting of the engine in cold weather.

● The 20 in 0W-20 indicates the viscosity characteristic of the oil when the
oil is at high temperature. AN OIL WITH A HIGHER VISCOSITY (ONE WITH A HIGHER VALUE) MAY BE BETTER SUITED IF THE VEHICLE IS OPERATED AT HIGH SPEEDS, OR UNDER EXTREME LOAD CONDITIONS."

(All caps & underline added for emphasis).

MontanaFJ61, perhaps you can provide some additional information on the new smaller oil galleries that you claim Toyota is using on the newest engines. Actual oil passage diameters or cross-sectional area would be useful, comparing "old" and "new" engine block designs.

 

[FJtest]

Thanks yeah that is posted somewhere on the site, nice to see it here also.

I honestly think that the 0w20 recommendation is for CAFE.

The 0W-20 oil recommendation is ONLY for the US (and Canada, which blindly copies US automotive standards), and was specified to meet the US Environmental Protection Agency's CAFE (Corporate Average Fuel Economy) requirements, NOT for achieving maximum engine life.

The 1GR-FE engine is used world-wide in many different Toyota vehicles, and in all countries which are NOT subject to CAFE legislation the recommended oil viscosities include 5W-30, 10W-30, 15W-40, and even 20W-50.

0W-20 is specifically excluded.

 

[FJtest]

Thanks for the chart; which owner's manual did it come from?

That photo is from the Owner's Manual from a 2015 GCC FJ , I believe.

Hersog's photo of the same page from an Australian manual shows the same viscosity/temperature recommendations..