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ILSAC GF-6, API SP & dexos: Making Sense of New Oil Specs.

Written by Charleen

ILSAC GF-6, API SP & dexos: New Oil Specifications

Andy Arendt|

As engine-operating conditions grow more severe, so do the demands placed on your motor oil. Hence the need for updated oil specifications, like ILSAC GF-6, API SP and GM dexos1 Gen 2.

New engine hardware such as turbochargers, direct injection and variable valve timing (VVT) place increased stress on your engine oil. This, in turn, has led to the introduction of more strict more oil specifications.

Here’s what we’re going to cover:

  • How strict fuel-economy standards increase engine stress
  • What is LSPI (low-speed pre-ignition)?
  • How motor oil helps prevent LSPI
  • ILSAC GF-6, API SP and GM dexos
  • Do AMSOIL synthetic motor oils meet GM dexos, ILSAC GF-6 and API SP specs?

 

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Improved fuel economy

Corporate Average Fuel Economy (CAFE) standards require a fleet-wide average of about 40 mpg by 2026 in the United States.

To meet these requirements the automotive industry has focused on smaller, more fuel-efficient engines. In fact, most new vehicles now feature gasoline direct-injection (GDI), a turbocharger or both (T-GDI).

Severe operating conditions

Smaller, more-efficient engines that make the power and torque of higher-displacement engines undergo more severe operating conditions that can lead to…

  • Severe engine knock, also called low-speed pre-ignition (LSPI)
  • Increased engine temperatures
  • Compromised fuel injectors
  • Increased wear and deposits if the oil isn’t up to snuff

The biggest motor-oil-related challenge on the horizon is LSPI, which can destroy pistons and connecting rods.

LSPI can cause cracked pistons and rods

LSPI is the spontaneous ignition of the fuel/air mixture before spark-triggered ignition.

It is another version of pre-ignition. Pre-ignition (engine knock) has been around since the beginning of internal combustion engines.

LSPI, however, occurs under low-speed, high-torque conditions, such as taking off from a stoplight in T-GDI engines.

This scenario can create conditions where the fuel/air ignites too early in the combustion cycle, throwing off the engine’s timing.

The expanding combustion charge collides with the piston as it’s moving up the cylinder, potentially destroying the pistons or connecting rods.

Oil can help prevent LSPI

Experts suggest the cause is due in part to oil/fuel droplets or deposits in the cylinder igniting randomly. The droplets and deposits contain enough heat to ignite the air/fuel mixture before spark-triggered ignition.

Oil formulation can play a role in reducing LSPI.

Certain motor oil ingredients can promote LSPI, while others can help reduce it. It’s tempting to think, “Well, dump a bunch of ingredients into your formulations that help reduce LSPI.” But some ingredients that help reduce LSPI have been limited over the years in motor oil formulations for other reasons.

It truly is a scientific balancing act confronting oil formulators. It’s no easy task to formulate motor oils that deliver excellent wear protection, resist the increased heat of turbocharged engines, prevent deposits, act as a hydraulic fluid and, now, combat LSPI.

The performance of the entire formulation – not just one or two ingredients – is what counts.

ILSAC GF-6, API SP and GM dexos

Next-generation motor oils need to pass an LSPI test to meet these new demands.

General Motors was first out of the gate and required oils to pass its own LSPI test. Its GM dexos1 Gen 2 specification took effect Aug. 31, 2017.

The latest American Petroleum Institute (API) specification, API SP, took effect in May 2020. As did ILSAC GF-6, the latest spec from the International Lubricants Standardization and Approval Committee. For the most part, it mirrors API specifications.

ILSAC has set a new precedent in the passenger-car motor oil market by splitting its specification into two parts. One of the main differences between the two specifications is compatibility.

See the chart below. Both versions focus on wear protection, prevention of LSPI and improved engine cleanliness. However, GF-6B features a more stringent fuel economy test.

Engine oils can easily be identified as ILSAC GF-6A or 6B by the API emblem on the front label of the packaging. A shield represents the GF-6B specification, while the traditional starburst indicates a GF-6A product.

Both ILSAC specifications meet the industry-standard API SP specification which is most commonly found in owners’ manuals.

Relax…for now

For now, you don’t have to worry too much about LSPI.

Your vehicle’s computer is programmed to avoid operating conditions that lead to LSPI. But, operating your engine under those conditions does promise fuel economy gains.

AMSOIL meets the latest specs

AMSOIL synthetic motor oils meet or exceed the latest industry standards, including ILSAC GF-6, API SP and GM dexos1 Gen 2.

You can safely use our synthetic motor oils in engines that call for those specifications.

In fact, AMSOIL achieved 100 percent protection against LSPI in the engine test required by GM’s dexos1 Gen 2 specification.*

Shop AMSOIL Synthetic Motor Oil

*Based on independent testing of Signature Series 5W-30, XL 5W-30 and OE 5W-30 in the LSPI engine test as required for the GM dexos1® Gen 2 specification.

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Figuring out Engine Knock

Written by Charleen

Why Does My Engine Knock? 3 Possible Explanations.

John Baker|

There are a few different reasons your engine might make a knocking, ticking or pinging sound. Let’s break each down and talk about what might be happening.

Is it an engine knocking sound, tick or ping?

One driver’s knock is another driver’s tick. Or ping. Still others compare the engine knocking sound they hear to marbles rolling around inside a coffee can.

The spontaneous ignition of air/fuel inside the cylinders is a common source of engine knock.

While the description of the sound may differ, the circumstances under which it occurs are often the same – low-speed, high-torque conditions common when you’re accelerating.

Engine knock typically occurs during low-speed, high-torque conditions, like when you’re accelerating.

How engine knock occurs

Say the clock has struck 5:00 and you make a bee-line to your truck and take off for home. When you mash the accelerator out of the parking lot, that’s when you hear an engine knocking sound. Or ping. When you let off the gas, it goes away.

This is likely due to either pre-ignition or detonation. They’re effectively the same phenomenon, but they occur at different times.

In a properly running engine, spark-triggered ignition typically occurs a few degrees before the piston reaches top dead center (TDC). This careful timing ensures the downward force of the exploding fuel/air mixture works in tandem with downward piston momentum, resulting in optimum efficiency and power.

That’s bad timing

Pre-ignition (and its cousin, low-speed pre-ignition [LSPI]) are abnormal combustion events that throw off this precise balance. Under certain conditions, the fuel/air can spontaneously ignite too early in the combustion cycle. Sometimes low-octane fuel is to blame; sometimes it’s deposits on the piston crown.

Fuel with too low an octane rating for your engine can sporadically ignite prior to the piston reaching TDC.

Or, chunks of carbon can heat up and create a hot spot that effectively ignites the fuel/air before the plug fires. Then, when the plug does fire a fraction of a second later, the two flame fronts collide. In certain conditions, they can clash with the upward-moving piston. The resulting shock wave rattles the piston inside the cylinder, creating the knock, ping or can-of-marbles sound you hear.

Detonation has the same effect, except it occurs after the plug fires.

Computers in modern vehicles can detect engine knock and compensate by adjusting engine timing. Though it saves your engine from destroying itself, performance and fuel economy can suffer.

Tick, tick, tick

Say your engine is ticking like a time bomb, especially in the morning when it’s cold. You likely have a valve-train issue.

Your engine uses intake valves to feed clean air into the cylinders and exhaust valves to kick spent combustion gases out. The valves open and close thousands of time per minute in a choreographed whirlwind of activity.

top dead center valve timing

A finely balanced system of parts – rocker arms, valve stems, cam lobes, lifters – control their movements. The clearances between these parts, known as lash, can become loose (or sloppy, in automobile nomenclature). When that happens, all those moving parts clattering against each other can create a ticking sound.

It’s especially noticeable in the morning before the oil has had a chance to circulate throughout the upper end of the engine.

Many engines use hydraulic lifters, which use an oil-pressure-assisted plunger and spring to compensate for lash, helping ensure the system runs smoothly and quietly.

Proper oil pressure plays a big role in valve-train operation and noise. Low oil pressure can reduce the effectiveness of hydraulic lifters, increasing lash. This is most likely to occur with a low-quality conventional oil that thins at high temperatures, preventing the engine from developing good oil pressure.

If the rods are knockin’…

Rod knock is yet another possible explanation for your engine knocking sound.

Your engine is built with a designed clearance between the crankshaft journals and the connecting rods. In a properly running engine using a good oil, the motor oil fills those clearances and prevents metal-to-metal contact.

But, let’s say you’ve been using a poor-quality conventional oil.

At high temperatures, the oil thins and the fluid film weakens. The pressure between the crank journals and connecting rods squeezes the oil from the clearances. Now, metal is riding on metal, wearing the surfaces and widening the clearances. Eventually the clearances widen so much that you begin to hear the metal surfaces clattering against each other. Eventually, they’ll weld together and destroy the engine.

Quieting a noisy engine

This all sounds dire. But you can sometimes address pre-ignition by using a higher octane gas or by cleaning deposits from your engine with a fuel-system cleaner like AMSOIL P.i. Performance Improver.

Buy AMSOIL P.i.

Using a higher-quality oil that flows better in cold weather and maintains its viscosity when hot can sometimes quiet a valve-train tick.

Shop AMSOIL Synthetic Motor Oil

Rod knock is the worst of the three. Once the clearances between the crank journals and connecting rods have widened due to wear, it’s just a matter of time before catastrophic damage.

In any case, visit your mechanic and take care of the problem before it gets worse.

The bottom line…

The moral of the story is simply to pay a little more now to maintain your vehicle rather than spend a lot later to fix it.

Use a high-quality oil that stands up to extreme heat and maintains correct oil pressure. Periodically clean combustion chamber deposits with a fuel additive, such as AMSOIL P.i.

Doing so can help keep your vehicle running properly and quietly for years.

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Where Oil Goes and What it Does

Written by Charleen

The Responsibilities of Your Motor Oil

A typical engine contains hundreds of parts, none of which could function properly without oil. Far from a simple commodity, oil is a dynamic enabler of performance. It must lubricate, cool, protect, seal, actuate components and more. And it must do it all while exposed to tremendous heat and stress. Here, we highlight key areas where oil goes inside your engine and what it does once it’s there.

Variable Valve Timing (VVT)

To increase fuel economy and reduce emissions, most modern engines use VVT systems to adjust when the valves open and close. VVT systems use motor oil as a hydraulic fluid to actuate cam-phaser components. Solenoids, like the one shown here, control cam-phaser timing. These solenoids contain tiny openings through which the oil must flow. Even minimal varnish or deposits can disrupt the system, triggering a check-engine light. The oil must maintain viscosity to function as a hydraulic fluid while resisting deposits to maximize VVT system performance.

Valves and Seals

Valve seals prevent oil from running down the valve stems. This keeps the oil on valvetrain components and prevents it from entering the intake and exhaust ports and burning, increasing oil consumption. The oil must condition these seals to prevent drying, cracking and leaking. The oil also helps cool the valves and control cylinder-head deposits, helping prevent valve sticking.

Main Seals

The seals at the ends of the crankshaft keep the oil inside the engine. The oil must condition seals to prevent drying, cracking and leaking.

Wrist Pins & Undercrowns

Crankshaft eccentrics splash-lubricate the cylinders, wrist pins and piston undercrowns. Some engines have small nozzles that spray oil directly onto the wrist pins and undercrowns. The rapidly spinning crankshaft causes air entrainment in the oil, creating foam. If foam bubbles in the oil pass between metal parts, they collapse and cause metal-to-metal contact. The oil must contain anti-foam additives to quickly dissipate foam. The oil must also contain detergent additives to help keep the wrist pins and undercrowns clean.

Connecting Rods & Main Bearings

Combustion drives the pistons down the cylinder, creating intense pressure between the connecting rods, main journals and bearings. Oil molecules act like microscopic ball bearings that support this pressure and allow the rods and crankshaft to rotate without metal-to-metal contact. The oil must maintain its protective viscosity despite increased pressures, temperatures and shearing forces. If the fluid film weakens, the oil will squeeze from between the journal and bearing clearances, resulting in metal-to-metal contact and bearing wear.

Camshaft

The camshaft and lifters open and close the intake and exhaust valves. To prevent wear, the oil must form a strong fluid film that separates the cam lobes and lifters. It also must contain robust anti-wear additives to maximize the life of the camshaft and bearings. As the image below shows, AMSOIL Signature Series 0W-20 Synthetic Motor Oil did an excellent job protecting against cam wear in rigorous, third-party testing.

Pistons, Rings & Cylinders

The pistons compress the air in preparation for combustion. The piston rings perform several critical functions: they must seal the combustion chamber, return excess oil on the cylinder walls to the sump and transfer extreme piston-crown heat to the cylinder walls.

To prevent wear despite intense heat and shearing forces, oil must maintain a strong, consistent film between the rings and cylinder walls. It also must prevent deposits that cause ring sticking, increased oil consumption, compression changes and low-speed pre-ignition (LSPI).

Signature Series Synthetic Motor Oil achieved 100 percent protection against LSPI1 in the engine test required by the GM* dexos1® Gen 2 specification – zero occurrences were recorded throughout five consecutive tests.

Oil Galleries & Passages

An engine contains an intricate network of oil galleries and passages that carry oil to components. Passages in the crankshaft, for example, carry pressurized oil to the rod and main bearings, while similar passages in the upper end carry oil to the valvetrain. Oil that thickens in the cold can fail to flow through narrow passages and starve the engine of oil. Sludge, meanwhile, can plug passages and have the same effect. The oil must remain fluid when the temperature drops, and it must prevent sludge.

Oil Pick-Up Tube Screen

The oil pump draws oil through a fine screen and pressurizes it so it can flow through the oil galleries and passages to the bearings and valvetrain. Sludge can plug the screen, starving the engine of oil. Oil that thickens too much to pass through the screen has the same effect. Therefore, oil must remain fluid when cold to pass through the screen and flow throughout the engine at startup (when most wear occurs). The oil also must prevent sludge to keep galleries and passages clean, ensuring maximum oil flow.

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Signature Series Motor Oil Protects Engines From Low-Speed Pre-Ignition

Written by Charleen
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SIGNATURE SERIES Protects Engines from Future Industry Problem

LSPI can destroy pistons and connecting rods, bringing an engine to a standstill in seconds. Original equipment manufacturers (OEMs) like General Motors (GM)* have addressed the issue by designing tests to gauge a motor oil’s ability to prevent these destructive events. Signature Series achieved 100 percent protection against LSPI1 in the industry-standard test.

OEMs have been aggressively downsizing engines to meet strict fuel economy and emissions standards while improving power and torque. Most new engines today use some combination of turbochargers, direct-fuel injection and variable valve timing to make more power than their larger counterparts while delivering improved fuel economy.

This scenario seems like all upside for drivers. But today’s smaller, hotter-running engines pose significant challenges to lubricants. The latest is a phenomenon called low-speed pre-ignition (LSPI), also known as “super knock,” which can destroy pistons and connecting rods.

What Is LSPI?

LSPI is another version of engine knock, which has been around since engines were invented. In this case, it occurs under low-speed, high-torque conditions in turbocharged gasoline direct-injected engines – like when you’re taking off from a stoplight. LSPI is the spontaneous ignition of the fuel/air mixture prior to spark-triggered ignition. This form of pre-ignition is more destructive than typical engine knock.

No Magic Bullet

Just as your engine relies on a balanced network of components to function, the motor oil needed to protect it requires additives with the right qualities at the right quantities. While adding more of one ingredient or reducing another seems simple enough, small composition changes can have big impacts. We were determined to find a solution to the LSPI problem without sacrificing the performance of Signature Series in any way.

GM LSPI Test

OEMs like GM have addressed the issue by designing tests to determine a motor oil’s ability to prevent LSPI. The GM LSPI Test records the number of peak pressure events during high-load operation in a turbocharged engine over a five-hour period. Passing the test is required to meet the GM dexos1® Gen 2 specification.

Perfect Score

We armed Signature Series with an advanced detergent system that protects against harmful deposits and LSPI. Signature Series Motor Oil achieved 100 percent protection against LSPI in the engine test required by the GM dexos1 Gen 2 specifications – zero occurrences were recorded throughout five consecutive tests.

API SN PLUS Specifications

API SN PLUS is a recently released specification that was requested by the automobile industry to protect passenger vehicles from LSPI. AMSOIL anticipated this change, and the current formulations of Signature Series, XL and OE synthetic motor oil all meet or exceed the specification. Look for updated product labels featuring the new API “donut” in the near future.

Your customers can be confident that AMSOIL synthetic motor oils protect their modern engines against LSPI, helping their vehicles deliver years of reliable service. For more information on the dangers of LSPI, visit www.amsoil.com/lspi.

 

Example of piston damage due to an LSPI event observed during the testing of a competitor’s motor oil. The red arrows indicate sections of the ring land that have broken away from the piston.

Achieved 100% Protection Against LSPI1

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Why Did We Reformulate Signature Series Synthetic Motor Oil?

Written by Charleen
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Why Did We Reformulate Signature Series Synthetic Motor Oil?

Local Sioux Falls note: We are reposing this article from last fall as it is important to realize the changes coming and how these enhancements will only add to the performance on older vehicles too.

AMSOIL’s Signature Series likely already exceeds the future API specification which hasn’t rolled out yet and we know other larger competing lubricant companies are having issues with LSPI (read more below).

John Baker|

Simply put, we reformulated Signature Series Synthetic Motor Oil to solve problems.

For all the derision heaped upon the internal-combustion engine, it remains our primary mode of propulsion. And, despite the gains of hybrids and electric vehicles, it will remain so for the foreseeable future.

One reason is the tremendous efficiency gains gas and diesel burners have made since the 1970s. The loud, proud cast-iron powerplants of yesteryear may still quicken your pulse when they roar past powering a hot rod or classic car, but they can’t match the fuel economy and reduced emissions of the engine likely powering the vehicle you drove to work today.

That’s due to the widespread use of turbochargers, direct fuel injection, variable valve timing and lightweight materials.

But, despite their many benefits, modern engines present several challenges, and it’s up to the motor oil to solve them.

Four little letters, one big problem

One of the biggest is low-speed pre-ignition (LSPI). If you read the AMSOIL blog, you’ve heard about LSPI by now. LSPI is such a big deal that it’s the driving force behind the next generation of motor oil performance specifications.

In a nutshell, LSPI is the spontaneous ignition of the fuel/air mixture prior to spark-triggered ignition. It occurs in modern turbocharged, gasoline-direct-injection (T-GDI) engines, and it’s another version of pre-ignition, which has been around since engines were invented. In this case, though, it occurs under low-speed, high-torque conditions and is much more destructive than typical pre-ignition.

Computers to the rescue

Automakers can program their vehicles to avoid operating conditions that invite LSPI. The problem, though, is that programming the engine to operate on that “ragged edge” that invites LSPI promises fuel economy gains of up to 10 percent.

With CAFÉ standards looming, automakers are eager to realize those efficiency gains.

But they can’t until motor oils hit the market that help prevent LSPI. Motor oil formulation plays a big role in fighting LSPI, so much so that the next generation of motor oil specifications requires oils to pass an LSPI test. The forthcoming API SP and ILSAC GF-6 specifications aren’t scheduled for introduction until fall 2019, however.

Some automakers have grown impatient and have requested that the API, which licenses ILSAC GF-5, supplement the current specification with an LSPI test requirement. That could happen as early as January, 2018.

General Motors is ahead of the game. Its proprietary dexos1® Gen 2 spec, introduced in August, includes an LSPI test.

An oil that solves problems

Which brings us back to Signature Series. We want our flagship motor oil to stand alone as the best motor oil in the world, and preventing LSPI is one prerequisite to achieving that goal.

So we subjected it to an LSPI engine test.

The result? Signature Series Synthetic Motor Oil provided 100 percent protection against LSPI* in the engine test required by the GM dexos1 Gen 2 specification.

In short, the oil solves a major problem plaguing the industry right now.

But wait, there’s more…

What about the old standbys, like engine wear and extreme heat?

Here, too, Signature Series excels.

From the day your engine fires to life, friction tries to wear away bearing surfaces, cylinders, piston rings and other components. Left unchecked, it’ll render your pride and joy a gutless, wheezing shadow of its former self. Eventually, something can break completely.

We formulated Signature Series to deliver next-level wear protection. But we know you want proof, not promises.

In the API Sequence IV-A Engine Wear Test required for the API SN specification, Signature Series delivered 75 percent more wear protection than required**.

What does that mean for you?

An engine that lasts for years and delivers maximum horsepower long after you’ve made the final payment. To prove it, we installed Signature Series 5W-30 Synthetic Motor Oil in a Ford F-150 with a new 3.5L Ecoboost engine to test its ability to protect turbocharged direct-injection engines from torque and horsepower loss during extended drain intervals up to 25,000 miles. Power sweeps were done at the beginning and end of the test to evaluate horsepower and torque retention. As the graph shows, Signature Series helped maintain engine performance throughout the 100,000-mile test.

Fights engine deposits

Engine deposits, too, do their best to sideline your vehicle. High heat can breakdown motor oil, leading to piston ring, piston crown or valve deposits, which erode horsepower and efficiency. In severe cases, your engine can fail altogether.

Heat is more prevalent in T-GDI engines. Turbos run on exhaust gases that can exceed 1,000ºF and can spin more than 150,000 rpm. 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 completely.

Again, Signature Series solves the problem of extreme heat. We challenged Signature Series to the GM Turbo Coking Test, which consists of 2,000 cycles of extreme heat soaks. An oil must limit the temperature change within the turbocharger to 13 percent or less to pass the test. Signature Series limited the temperature increase to only 3.6 percent, protecting the turbocharger 72 percent better*** than required by the GM dexos1® Gen 2 specification.

Signature Series controlled heat and minimized performance-robbing deposits on the turbo bearing and shaft surfaces.

And, lest we forget, the performance of Signature Series Synthetic Motor Oil lets you extend drain intervals to 25,000 miles/one year if you choose, even in turbocharged engines.

With challenges to engine protection and performance mounting – and new problems cropping up – it’s vital we stay one step ahead.

That’ll help you continue to get the best protection and most years out of your vehicles.

BUY SIGNATURE SERIES SYNTHETIC MOTOR OIL

* Based on independent testing of AMSOIL Signature Series 5W-30 motor oil, in the LSPI engine test as required for the GM dexos 1® Gen 2 specification.
** Based on independent testing of AMSOIL Signature Series 0W-20, in ASTM D6891 as required by the API SN specification.
*** Based on independent testing of AMSOIL Signature Series 5W-30 in the GM turbo coking test.

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