Originally Posted By: 330indy
...maybe for mileage, but under hard usage considering engine longevity, I hesitate on this topic. Thin oil gets squeezed out of the connecting rod bearings. I like to occasionally drive hard and don't want to have to think about it.
Everyone keeps harping on the fact that the 20W oils are only supposed to be for mileage, and that they adversely affect engine longevity. Is the phenomenon you describe (engine oil squeezed out of connecting rod bearings) scientifically documented?
Consider this: Toyota is one of the companies advocating 20W oils in a lot of their engines. Toyota has also developed a world-wide reputation for reliability. Your claim basically says that Toyota is only interested in the tiny gain in mileage and is willing to take a huge black eye over engine failures down the road.
Sorry - that doesn't make any sense.