To your engine, oil is what keeps all the various parts working together in harmony. Nothing is more important that feeding your engine with the right lubricants. Your Chevy doesn't have to be a lost cause at 150,000 miles. We're going to show you how to get 250,000 to 300,000 miles out of your classic or late-model by doing nothing more than using the right lubricants and changing them out on a regular basis.
What Oil Does
Lubrication performs two basic functions. It keeps moving parts from touching each other and it carries heat and corrosive contaminants away from those moving parts. Engine oil has the most intimate contact with an engine's moving parts, including the hottest parts like exhaust valve stems and piston rings. It has to have qualities that allow it to stand up to the toughest conditions imaginable.
When lubricating oil breaks down under high-heat conditions it stops protecting moving parts, which is what leads to engine failure. Not only does engine oil keep moving parts from getting together, it also coats these parts to prevent destructive oxidation and corrosion. Additives in the oil contribute to the prevention of corrosion and the resulting deterioration. Detergents and dispersants contribute even further to prevent sludge and carbon buildup.
Sludge is something we seldom see anymore because fuels and lubricants have become more refined. Gasoline is free of lead, which caused its share of sludge. In the old days, engine oil technology wasn't as refined either, cooking onto hot surfaces and lumping into one hot mess for rebuilders. And when the oil wasn't changed on a regular basis it only made the sludge buildup worse.
Engines are lubricated via pressure, splash, and fog. Oil meets moving parts under pressure at the crankshaft and camshaft journals and bearings. It is also supplied under pressure at the lifters and rocker arm shafts. The layer of oil between moving parts is known as an oil wedge. The oil wedge is a liquid bearing on which moving parts ride without touching each other. Moving parts get together whenever that oil wedge is compromised.
The oil wedge is compromised whenever the engine is shut down and it has time to sit. Oil drains off of moving parts, which have time to get together. When you hit the starter moving parts have brief, direct contact until oil under pressure reaches those critical parts. Splash and fog lubrication takes time to get slung around before it coats cylinder walls, pistons, and pins. And forget lubrication at piston rings. Piston rings have direct contact with the cylinder walls, which have some lubrication but not enough. Because both the cylinder wall and the rings are typically made of iron, wear tends to be uniform in both. As the rings and the walls wear they shed microscopic amounts of metal into the oil.
Why Change Oil?
It has been proven clean oil greatly enhances engine life by protecting moving parts. You should change the engine oil every 3,000-5,000 miles, even if you're running synthetic. We will get arguments on this one, but the cleaner the oil the better. We have seen proof of this again and again in more than 40 years of tinkering with automobiles. Changing oil, regardless of the type of oil you use, rids your engine of contaminants that can cause harm to an engine if left unattended.
Contaminants can have a corrosive effect on moving parts. Microscopic metal particles from normal wear and tear can take a toll on moving parts when they sit in the oil wedge and contact moving parts. Iron particles will score soft bearing surfaces. In fact, did you know aluminum bearing surfaces are made that way to absorb metal particles and other contaminants? Hard iron particles sink into the soft bearing surfaces, which protects the crank and cam journals from scoring. Always change the oil filter any time you change the oil.
Synthetic vs. Conventional
We spoke with Dan Peterson, Vice President of Technical Development, at AMSOIL about the choice between synthetic and conventional oil. "It depends on application and what you want from your motor oil. There are a lot of areas where it makes sense to use synthetic. And there are applications where you're better off with conventional," Dan comments. "For anyone who is interested in greater performance, protection, and longevity synthetics are going to do a better job."
Dan goes on to say, "Breaking that down further, when you get into temperature extremes—very high temperatures along with very low temperatures—AMSOIL synthetics are going to provide much better performance in these extreme environments. From the high temperature side of it the base oils as well as the additives, the synergy of these elements, provides better oxidation protection, and protection from carbon buildup, which come as a result of these high temperatures."
"From the low temperature side of it you just don't get the flow of lubricant when you need it," Dan adds. "The really bad wear comes when you start your engine and lubricants don't get there quickly enough to prevent contact. Synthetic lubricants flow better at low temperatures and they tend to stay," Dan explains. "Synthetic lubricants tend to stay, which means you have lubrication on moving parts upon start-up."
Another option to consider is synthetic lubricants in your driveline, be it an automatic transmission or manual shift. Ditto for your Chevy's differential, which can live happily with synthetics.
100% FREE QUOTES ON ALL INSURANCE NEEDS!!