Last time I replaced transfer case oil in my 2017 LX, I got Toyota original 08885-81080 oil. Yesterday I was looking to buy again as getting close to replace again. Now when I plug in that part number on Bell Lexus website, it takes me to 08885-02806. Website also says it supersedes 08885-81085. The original oil was already expensive around $70-80 per quart and this new part number is double the price around $160. To me it's extremely expensive but would go that route if it is worth. Also, the specs are changed. From 75w to 80w now. 08885-81085 which shows superseded was 80w oil.
I have to buy two quarts for the job. Old part is still available online at other retailers and eBay.

Like to get input to decide which one should I buy. Is this change in spec made to improve longevity or drive quality? I am confused now. As always, I would trust recommendations on this forum then given by dealership.

Thanks in advance for advice.