Originally Posted by firebirdguy

ok, was just curious what you meant by that. & just an FYI, but thicker oil doesn't help anything related to heat or turbos... oils main job besides lubrication is cooling internal engine parts & a thinner oil flows better than a thick oil, therefore cooling better.

also, thicker oil isnt better on start up, same thing applies for flow on start up, it takes a lot longer for a thicker oil to get pumped through the engine at start up, cold or hot. dont get too hung up on pressure, pressure is not what protects engine parts, its the flow & ability of the oil to get in & out of tight clearances, pressure is just a factor of the pump vs bearing clearances & i doubt your clearances are worn so much that you need thicker oil.

a standard rule is 10psi for every 1000 rpms, so at start up you want flow more than psi. think of it this way, you can try to pump oil through a very small hole like a syringe needle, it will have very high pressure because it can barely get out of the opening, but the volume of oil will be very very minimal.... same applies to an engine, you want a minimum psi to keep metal parts from touching, but just as important or more, is having enough flow/volume. either oil will work ok & 10/30 wont blow up the engine or anything... but if your oil pressure light isn't coming on with 5/30, its probably better for the engine to run the weight toyota calls for. thicker oil isnt better if its not called for or needed.