Why Synthetic Motor Oils Are Recommended for Today's Advanced Automotive Engines, Part 1
From changing consumer demands, to regulatory requirements calling for greater fuel efficiency and lower emissions, the global automotive market is constantly evolving. At the heart of this evolution is the ongoing transformation of the traditional, internal combustion engine, which has powered vehicles around the world for much of the last century.
Over the past decade, manufacturers have made extraordinary advances in automotive design and engine technology. Now these engine design advancements, such as turbochargers, gasoline direct injection, variable valvetrain systems, clean diesel engines, and hybrids, are increasingly making their way into the mainstream automotive market.
Along with changing the current landscape of automobile offerings, these technologies serve as a valuable preview of the future, where various engine styles and types will be used by manufacturers to meet rapidly expanding consumer and marketplace needs.
As these advanced engine designs and future engine technologies continue to become more common, drivers will need to know how best to protect and maintain their vehicles. And particularly why, when it comes to protecting today's engine types, using a fully synthetic motor oil is a far better option than relying on a conventional, mineral-based oil.
The Rise of Turbochargers
Traditionally used to increase power output from high-performance engines, turbochargers are increasingly being used by leading manufacturers in everyday passenger vehicles, including compacts and sedans, as a means to increase engine output and improve fuel economy.
While turbochargers are a great way to improve the performance of a vehicle, they operate at very high temperatures.
Turbochargers feature shafts which spin inside bearings at extremely high speeds that are driven (via a turbine) by hot exhaust air as it exits the engine and thus can be exposed to intense heat. The turbine/shaft assembly can spin at speeds of up to 200,000 revolutions per minute - which is approximately 40 times faster than most car engines. Over time, and without proper lubrication, these bearings and other turbocharger parts can accumulate varnish and other high temperature deposits, and therefore may experience detrimental wear and tear. With such extreme heat, a high performance, fully synthetic lubricant is the best way to protect turbochargers.
Conventional motor oils are less suited for use in turbochargers because they tend to become unstable when exposed to high temperatures and, over time, can start to burn, or cook, inside the turbocharger, generating deposits -- a process called "coking."
These deposits can clog oil passages and channels, restricting oil flow through the turbocharger, which can make turbocharger operation unstable. Ultimately, this can lead to turbocharger seal issues, higher oil consumption, and even turbocharger failure.
On the other hand, fully synthetic motor oils, such as Mobil 1, offer valuable high-temperature stability. They are designed to resist oxidation and protect critical engine parts even under some of the most demanding conditions, thus reducing deposit formation and enhancing the performance, reliability and durability of a turbocharged engine.
While traditional gasoline engines work by drawing a mixture of gasoline and air into a cylinder where it is then compressed by a piston and ignited with a spark -- resulting in an explosion that drives the piston downwards and produces power - GDI engines feature a slight, yet significant distinction.
In a gasoline direct-injection engine, air and gasoline are not pre-mixed. Rather, the air comes in through the intake manifold, while the gasoline is injected directly into the cylinder. This system allows more precise control over the amount of fuel injected and exactly when the fuel is introduced into the cylinder. The result is more efficient combustion across the engine's operating range.
The major advantages of a GDI engine are increased fuel efficiency and high power output. The cooling effect of the evaporating fuel, injected directly into the cylinder in small, even amounts, rather than outside it, makes higher fuel economy and performance possible. Emissions levels can also be more accurately controlled using the GDI system.
As a result, a synthetic motor oil that is specially designed to withstand high levels of friction and heat can help minimize oxidation, and cope better with particulate matter. Consequentially, it represents a far better lubricant choice than a conventional, mineral-based oil.
When exposed to the greater heat produced by a GDI system, conventional oils are more prone to vaporization, which leads to oil being drawn up into the air intake and subsequently deposited on the intake valve. These intake valve deposits can cause a reduction in fuel economy and performance.
By comparison, fully synthetic motor oils, such as Mobil 1, offer greater thermal and oxidative stability, and can deliver better overall protection for GDI systems.
Exemplifying the growing popularity of GDI systems, many OEMs are further optimizing GDI technologies by combining them with turbochargers, variable valve timing, and/or variable intake manifold designs to generate improved torque and power, as well as better fuel economy.
Today, most major OEMs have a variety of GDI offerings. In the future, many OEMs likely will incorporate GDI more often into their engine designs.
Today, the global automotive market is evolving at a rapid pace.
Regulatory requirements are calling for greater fuel efficiency and lower emissions. Consumers are demanding more than ever, looking for cars that not only deliver exceptional performance, increased power and durability, but also offer enhanced fuel economy.
To meet these marketplace demands, the world's leading OEMs are increasingly developing and introducing a host of advanced engine technologies, such as turbochargers, GDI systems, variable component systems, hybrids and clean diesel systems. Compared to traditional combustion engines, these new engine types are typically smaller, deliver more power and better fuel economy, and produce fewer CO2 emissions.
In the next 10 to 20 years, the technology evolution for engine design likely will continue at an even more rapid rate, further changing the automotive marketplace and putting more emphasis than ever on the value that synthetic motor oils can deliver.
Next week, we'll discuss how synthetic oils are especially beneficial in hybrid propulsions systems, engines using variable component technologies, and 'clean' diesel technologies.
By Kevin Chinn
Kevin is an engine oil technical advisor for ExxonMobil Lubricants & Petroleum Specialties Company. He is a member of the Mobil 1 Research Team based at the company's Paulsboro Technology Center in Paulsboro, New Jersey.
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