Tuga,

From what I gather engine oil has a buffering characteristic that neutralizes the acids that you talk about, predominantly sulfuric and nitric. As the engine oil ages, the buffer/neutralizing capability diminishes. These acids, if left unchecked, attack the metals in the engine, damage surfaces and possibly lead to early engine failure. As the engine sits, the thin layer of oil covering vital surfaces becomes ever thinner until virtually nothing is left to buffer against the acids that may form due to condensation. This situation is made worse if the oil is worn out; i.e., it's buffering/neutralizing capability is down by 50%. Get some fresh stuff in there and you stand a better chance of guarding those precious surfaces. This is my layman's understanding.


David Brady
'02 Blue Bird Wanderlodge LXi,
Series 60 Equipped,
Asheville, NC