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How Turbochargers and Direct Injection are Changing the Industry

How Turbochargers and Direct Injection are Changing the Industry

Note: This was an older article I never added here but still contains important things to highlight. Keep in mind the actions needed to extend the life of these engines.

Turbocharged, gasoline-direct-injection (T-GDI) engines have been the topic of many AMSOIL blog posts and other publications the last few months, and for good reason. In recent years these technologies have taken the automotive industry by storm. In fact, industry experts predict that by 2020 nearly every new vehicle will feature at least one of these components.

Why the changes?

You might find yourself asking, “What’s wrong with the good ‘ol engines we all know and have used for years?”

Remember a post back in May about CAFÉ requirements? Since the 1970s, the government has required each automaker’s vehicle fleet to deliver a minimum average fuel economy or face penalties. The minimum allowable fuel economy has steadily risen over the years and is scheduled to hit 54.5 mpg by 2025. To meet this goal, automakers have been turning to any technological advantage they can find, including turbos and direct injection.

Turbocharger 101

So, how does a turbo improve fuel economy anyway?

To find out, let’s look at how they work.

Turbos, which get insanely hot, push more air into the cylinders, increasing efficiency and power.

A turbo is essentially an air compressor that is powered by exhaust gasses. The gasses spin a turbine that pulls air through the intake and forces it into the combustion chamber. This improves combustion due to increased oxygen, which you experience as boosted horsepower and fuel economy.

Turbos sound like all upside to us drivers. More power, less fuel. What’s the problem?

Well, a turbo can spin upward of 230,000 rpm. Think of that for a second. For perspective, consider that the average vehicle today redlines at around 6,000 rpm, meaning the turbo can spin up to 38 times faster than your engine can operate. In addition, the gases that spin the turbine can exceed 1,000°F. Extreme speed coupled with blistering heat can lead to deposit buildup, known as turbo coking, which ultimately can ruin the turbo.

Engine oil is used to lubricate and cool the turbo. Using a high-quality synthetic oil, such as AMSOIL Signature Series Synthetic Motor Oil, helps reduce deposit buildup on turbo spindles and maintains performance. Another tip is to let your turbocharged vehicle idle for a minute or two after driving. The circulating oil will cool the turbo properly and reduce formation of performance-robbing deposits.

Let’s be direct

Gasoline direct injection (GDI) has also gained popularity with automakers. In fact, nearly all manufacturers use this technology to some degree.

GDI engines locate the fuel injectors directly in the combustion chamber, as opposed to the intake manifold as with a traditional port-fuel-injected engine. Doing so allows automakers to precisely control fuel-injection timing and, in some cases, perform multiple injections during the same piston stroke. Such precise control allows the computer to adjust the air/fuel ratio to as lean as 50:1 under certain conditions, whereas port-fuel-injected engines operate around 14.7:1. This precision results in improved fuel economy.

In a GDI engine, the fuel injectors are located in the fiery cauldron of the combustion chamber.

GDI engines are also equipped with a high-pressure fuel pump capable of generating fuel pressures up to 2,000 psi. In comparison, port-fuel-injected engines run on fuel pressure around 40 psi. Increased fuel pressure helps cool the cylinder and atomize the fuel more effectively for a more complete burn.

Again, GDI sounds like nothing but upside for us drivers, but there are drawbacks. With the injectors located in the combustion chamber, over-spray can hit the far cylinder wall, allowing fuel to wash past the rings and into the oil sump, contaminating the oil. Automakers are constantly changing piston designs to trap fuel in the combustion chamber, improving efficiency and reducing fuel dilution.

Another downside are intake-valve deposits. In a port-fuel-injected engine, detergent-rich fuel washes over the intake valves, keeping them clean. However, in a GDI engine, fuel no longer touches the backside of the valves, resulting in deposit buildup. Over time, these deposits can prevent the valves from seating properly, leading to reduced performance and fuel economy.

What it all means to you

In many cases, you won’t experience an issue with either your turbo or fuel injectors provided you perform regular maintenance and use a high-quality motor oil, such as AMSOIL synthetic motor oil like our 0W-30 Signature here in Sioux Falls, and a good oil filter. It’s also smart to clean the injectors and keep them functioning properly with a potent fuel additive, such as AMSOIL P.i.

That being said, when these technologies are combined, it can result in a potentially catastrophic abnormal combustion event, known as low-speed pre-ignition (LSPI). Check out an article about LSPI we wrote a couple months back.

LSPI is turning the lubrication industry on its head, requiring oil manufacturers to reformulate their motor oils to combat LSPI in order to allow automakers to take full advantage of the fuel-economy benefits of T-GDI engines.

We’re proud to say that AMSOIL synthetic motor oils provided 100 percent protection against LSPI in the engine test required for the GM dexos1 Gen 2 specification.

NOTE: to pass the GM dexos Gen2 requirement, the oils the manufacturer suggests are only passed at the minimum which is a 20% pass rate so 4 failures out of 5 are accepted!! What a joke really.

I’ll leave you with one last comment: embrace the changes to modern engines and enjoy the performance and fuel economy gains they offer. And rest easy knowing that AMSOIL synthetic lubricants deliver the next-level protection needed to take advantage of today’s advanced engines.

OK, that was two comments.

Deposit protection is critical for turbocharged engines

Deposit protection is critical for turbocharged engines

Motor oil quality must stay ahead of the curve.

Matt Erickson | TECHNICAL PRODUCT MANAGER, PASSENGER CAR

It may be a good time to invest your retirement funds in a company that builds automotive turbochargers; they’re predicted to be in most new passenger cars/light trucks by 2020.

Matt Erickson AMSOIL INCAs such, we’ve focused quite a bit of time and energy on turbos and the challenges they present to motor oil. Today, I want to dive a little deeper into turbo tech and explain how they work and why AMSOIL will be synonymous with the subject of turbos in the coming years.

An engine is essentially an air pump, and the more air it ingests, the more fuel it can burn – and the more power it can produce. There are a few ways to increase the amount of air the engine takes in, but turbocharging has emerged as the favored choice of automakers.

As shown in the diagram, exhaust gases commonly exceeding 1,000ºF spin a turbine, often at more than 150,000 rpm, which drives the compressor that draws ambient air used to pressurize the combustion chamber. The added oxygen combined with direct injection and advanced engine-tuning helps the engine burn fuel more efficiently, boosting fuel economy. It also allows the engine to burn more fuel for increased power. As a result, a turbocharged four-cylinder engine can make as much power as a non-turbo six-cylinder engine. This advancement allows automakers to build vehicles with smaller, lighter engines that don’t sacrifice power or torque. Motorists enjoy the performance and fuel economy they demand, while automakers meet increasingly strict CAFE (Corporate Average Fuel Economy) requirements. A win-win situation.

As they say, there’s no such thing as a free lunch, and in this case, it’s the motor oil that ends up footing the bill. The turbo’s center section contains an oil-lubricated bearing. The tremendous heat and stress turbos create can cause some oils to break down and form harmful bearing deposits, known as turbo coking. Over time, turbos can suffer reduced performance, or fail altogether.

For this reason, auto manufacturers and oil companies – including AMSOIL – automatically include turbocharged vehicles in their severe-service category when prescribing oil-change intervals. The TEOST 33C Test (ASTM D6335), an industry-standard bench test that simulates turbocharger operating conditions, has taken on added importance in today’s automotive landscape. With the predicted rise in turbo use, it’s more important than ever for motor oils to protect against harmful high-temperature deposits to keep vehicles running properly. To meet the API SN Resource Conserving and ILSAC GF-5 motor oil specifications that are often recommended by vehicle manufacturers, a 5W-30 motor oil must limit total deposit formation to 30 mg or less in the TEOST Test.

Turbocharger Cutaway

In our recent published tests (deposits caused by lower quality base stocks in turbo equipped engines), AMSOIL Signature Series 5W-30 Synthetic Motor Oil held the total weight of deposits to 7 mg, well under the 30 mg limit required by the API and ILSAC, while Royal Purple® API 5W-30 and Mobil 1® Extended Performance 5W-30 came in just under the limit at 25.4 mg and 28.2 mg respectively. Signature Series 5W-30 Synthetic Motor Oil protects against harmful deposits on turbochargers 4X better than Mobil 1® Extended Performance and 3.6X better than Royal Purple® in industry-standard testing*.

We want our customers to understand the importance of protecting their turbocharged vehicles, and to know AMSOIL is devoted to offering protection beyond what is required by the industry. We are the only name for true automotive enthusiasts here in Sioux Falls!

*Based on independent, third-party testing of AMSOIL® Signature Series 5W-30, Mobil 1® Extended Performance 5W-30 and Royal Purple® API 5W-30 in the ASTM D6335 bench test required by the API SN Resource Conserving specification. For full test details visit www.amsoil.com/depositprotection.