There are four basic types of wear.
Fortunately, all four can be controlled with quality lubrication.
With the average cost of a new vehicle pushing north of $30,000, it’s no wonder people are hanging onto their vehicles longer than they have in the past. Folks that would have bought new vehicles every four or five years in the past are now commonly keeping their cars and trucks for 8 or 10 years or longer. Wage increases also have not always kept pace with the rising cost of living in recent years. As more people look to keep their vehicles longer, more of them learn that, without proper maintenance, vehicles might not last as long as they’d like. It is up to drivers to protect their investments.
"There is little more detrimental to your vehicle’s engine than wear, and lubricating oils are your first line of defense"
There is little more detrimental to your vehicle’s engine than wear, and lubricating oils are your first line of defense. Numerous factors contribute to engine wear, but all can be categorized as one of the following four basic wear mechanisms: abrasive, corrosive, adhesive and fatigue.
Abrasive wear is caused by foreign particles entering the engine, most commonly soot and dirt. Once inside the engine these particles become trapped between moving parts – the piston and cylinder, for example – and grind against their metal surfaces. Wear particles act as sandpaper, continuously rubbing and wearing away metal surfaces by rupturing the oil film separating moving engine parts, resulting in particle-to-metal contact. This contact creates friction and reduces energy efficiency.
Abrasive wear commonly occurs when dirt or other contaminants enter the engine through the air intake system. These contaminants cause excessive wear on rings, pistons and cylinders. Increased cylinder and ring wear can cause blow-by, which decreases compression and causes loss of power. An efficient filtration system can help prevent abrasive wear by blocking contaminants that would otherwise enter the oil sump and find their way into the system.
Corrosive wear is the result of rubbing action on a metal surface in conjunction with chemical attack. Combustion byproducts introduce acids into the oil sump. If unaddressed, these acids can build up in the system and oxidize or corrode the surface of sensitive areas, including lead- and copper-lined bearings and other soft yellow-metal surfaces. As the surfaces begin to corrode, pieces of oxidized metal break free and become wear particles in the system.
The most commonly recognized mechanism is adhesive wear, which occurs when metal surfaces come in contact under conditions of high load, speed or temperature. Surface irregularities, called asperities, touch and weld momentarily, then break off as the surfaces separate. The load applied to the two points of contact is so high that they bend and adhere to one another. Rough metal surfaces with larger microscopic hills and valleys are more susceptible to this type of wear. Adhesive wear can result in scuffing, scoring or seizure.
Fatigue wear originates from situations where the lubricating film is in place, but recurring stress like vibration or shock-loading causes cracks or pits over time. This is a common type of wear found in equipment that frequently starts and stops or changes speeds. Fatigue wear can develop in rolling element bearings as they pass over a stressed area repeatedly and, ultimately, develop cracks that release small bits of metal over time, leaving holes or pits in the surface. These holes or pits grow and connect, resulting in large losses of surface metal and catastrophic damage.
No Matter What Vehicle You Drive
Regardless of equipment type, bearings, gears and cylinders are susceptible to wear, and thus require high-quality lubricant protection. Choosing the proper viscosity for your oil will aid in wear protection by reducing the likelihood of metal-to-metal contact. A full-synthetic base oil provides a naturally higher viscosity index for improved shear stability, again helping to reduce wear by maintaining proper viscosity. Oil film strength is also a key wear-protection property. Adequate film strength provides a lubricant barrier between moving parts, ensuring friction is greatly reduced.
Being able to identify the symptoms of each mechanism is important in order to diagnose both mechanical and lubrication issues. AMSOIL synthetic lubricants offer outstanding wear prevention to help vehicles last longer, which is something everyone can benefit from.