oil viscosity

Alright what weights are you guys running and why? I saw this photo posted by squirrel concepts on IG and got me thinking.

obviously they’re talking about 22r/re’s specifically, however I’ve been told by many that running 10w-40 is perfectly fine in 1st gens (for the lifetime of the truck). My truck has 303k and I’ve been debating switching to a blend or running synthetic soon.
Anybody have a similar photo out of a 1st gen FSM?

Let’s hear your opinions!

 

5w-30 syn from Costco. Don’t need to over complicate.

 

From the owner’s manual

 

sae it is!

 

i use Napa 5w30 in the 3.4`s

I use 20-50 in all my 22Re engines from fresh to 250,000 miles plus for the last 22 years

 

Hot areas (like my home of Phoenix) can do the winter number higher with no problem. Peep the chart above. It probably won't even hit the 20s this year, so even 10W is low

 

2003 FSM:


10W-40 may cause the oil filter bypass valve to open more frequently at operating temperature, causing the engine to run on unfiltered oil more often.