Abrasion
Abrasion is wear caused by fine dust or dirt particles that enter the engine, mix with the oil, and then are rubbed between parts. This type of wear is the most common and damaging. The dust enters through leaks in the air filtration system or through the filter itself. Finely machined parts wear quickly when lubricated with gritty oil. For example, main bearings are most prone to failure because of dirt, not lack of lubrication.
CAUSE OF ABRASIONOff-road and dusty environments contain about 2,000 times the amount of dust found in normal air. Often, you can literally see it. Also, engine wear (amount of metal worn away) is directly proportional to the dust concentration in the air that is consumed. Air that is twice as dusty as normal will cause twice the normal wear. Air that is 2,000 times more dusty will cause 2,000 times the wear (assuming the dust enters the engine).
To minimize abrasive wear, avoid driving in dusty conditions. Also, make certain the air filter is of high quality and that there are no leaks in the filtration system. This includes any gaskets that seal machined surfaces of the air intake system.