Originally Posted by MN Driver
From an oil tribology perspective, the only need for a higher viscosity comes when there is not enough oil pressure between the bearing surfaces..... 5w30 will work with this engine as I've found bearing tolerances tighter on engines that run this viscosity
Thanks. It's good to get a reply from someone who actually THINKS instead of just blindly following whatever "the man" tells them in a manual. 0W-20 is great for a new engine but as the engine ages most mechanics advise switching to a thicker oil.
Also: I have no doubt the trend towards 0w-20 and 5w-20 among modern cars has less to do with protection, and more to do with increasing MPG numbers. Car companies don't care if your car engine experiences increased wear and dies 100,000 miles early, so long as they can claim +1 more MPG to the government and meet CAFE requirements.
On my old Dodge Shadow the recommendation was for 5W-30. For some reason my dad used 10W-40 when he did my oil changes, and that thing lasted 360,000 miles even with the thicker oil.