Which Oil Is Thicker Sae 30 or 40?

So, SAE 30 is a median thickness oil and SAE 40 is a slightly thicker than average oil.

Which is thicker 40 or 30 weight oil?

Obviously, a 10W-40 is thicker than a 10W-30 at high temperature. Armed with knowledge of viscosity grades, how can we put it to good use? Remember that using oil with a viscosity that is too high can result in excessive oil temperature and increased drag.

Is 40w thicker than 30W?

Forty-W oils are thicker and more viscous than 30W oils. The W indicates their "winter-grade" viscosity. Forty-W oils are less runny and do not travel as easily around the engine.