I'm having this discussion on another board. Is there any truth to this:
METhe 30W is the same regardless so stability will be the same when the engine heats up. 10W will just give some extra protection during startup, but not much over a 5W.
quote:I thought that the only difference between a 5W and a 10W in a dino was the start up weight. Someone enlighten me.
Other posterIt's not the same. Being a 30 wt. at temp isn't where the extra stability I'm talking about comes in. The spread between 5W and 10W when cold, and the different chemistry's used to achieve it are the reason why one oil is more shear stable than the other. Even though they both meet the requirement to be called a 30 wt oil at 100c, there are still differences in how the oil will behave at temp. over the drain interval.