What Does Viscosity Mean and Its Importance?

How does viscosity affect your engine, mileage and performance?

Motor oil viscosity is the measure of its resistance to flow. Low-viscosity oil (e.g. 0W-20) flows faster than high-viscosity oil (e.g. 20W-50).

To illustrate, think of water and honey. When poured from a container, water flows much faster than honey.

For more good information on oil viscosity including easy to understand charts, read this blog:

What Does Viscosity Mean (and How Does it Affect Your Engine)?

AMSOIL Signature Series and Turbochargers

AMSOIL Signature Series Protects Turbochargers

The turbocharger/direct fuel injection combo has emerged as automakers’ favored choice for producing powerful engines and meeting government fuel-economy requirements. The increased airflow turbos generate enables an engine to burn more fuel and produce more power, but this power comes at a cost. The tremendous heat and stress turbos create cause some oils to break down and form harmful bearing deposits through a process known as turbo coking. Over time, turbos can suffer reduced performance or fail altogether.

How Turbos Could Slow You Down

The deposits common to turbochargers can lead to:

• Blocked oil passages, oil starvation and eventual failure
• Reduced turbine speed – resulting in lower boost pressures, reduced performance and poor efficiency
• Oil breakdown and oil burning
• Expensive turbo rebuild or replacement 

The GM Turbo Coking Test

The Turbo Coking Test was designed to simulate the extreme operating conditions of a turbocharged engine. It evaluates a motor oil’s ability to resist deposit buildup in the oil passages and bushings of a turbocharger. Temperature increases within the turbo and the weight of any deposits are recorded.   

Test Parameters

Engine   -  2012 GM 1.4L

Duration   -  2,000 cycles of extreme heat soaks – approximately 537 hours

Measures   -  A motor oil’s ability to resist deposits in a turbocharger’s oil passages and bushings

Simulates   -   High-heat operation of a turbocharged engine 

Requirement   -  Temperature change within the turbocharger limited to 13 percent

Signature Series protects turbochargers 72% better than required by GM dexos1® Gen 21

The GM Turbo Coking Test requires an oil to 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, controlling heat and proving it protects against deposits common to high-temperature engine environments.

For more information or to buy AMSOIL Signature Series Synthetic Motor Oil

1Based on independent testing of AMSOIL Signature Series 5W-30 in the GM Turbo Coking Test as required for the GM dexos1 Gen 2 specification.

*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for use in the applications shown.

AMSOIL Signature Series Battles Sludge

AMSOIL Signature Series Battles Engine Sludge

Synthetic motoroil

The health of your engine depends on motor oil circulating quickly and efficiently through the system, but sticking components and obstructed passages inhibit motor oil from lubricating, cooling and protecting your engine. Engine “sludge” occurs when oxidized oil and contaminants build up on engine surfaces. It can restrict the flow of oil to the point of engine failure and costly repairs.

Sludge: Where It Starts & How It Ends

The valve cover and oil pan are generally the first areas sludge appears.
The oil pick-up tube screen is often the next spot it accumulates, impeding oil flow through the system.
What begins as a thin film of lacquer or varnish deposits eventually bakes into an expensive mess.

The Sequence VG Engine Test

Engine failures due to sludge are often caused by a clogged pick-up tube screen – the motor is effectively starved of oil. The Sequence VG Engine Test determines how well an oil resists sludge formation and keeps the lubricant flowing freely throughout the system. The test is required for API SN PLUS – a specification recommended by most domestic vehicle manufacturers.

TEST PARAMETERS

Engine

Ford* 4.6L V-8 

Duration

216 hours

Measures

Sludge and varnish deposits, piston ring sticking, clogged oil pump screens and roller pin wear

Simulates

Taxi, delivery or commuter vehicle service

Requirement

Oil pick-up tube screen limited to 10 percent blockage

The Results

Signature Series Synthetic Motor Oil was subjected to the Sequence VG to measure its ability to prevent sludge. As expected, Signature Series produced an oil pick-up tube screen virtually free from sludge (see image). Our unique combination of detergents and high-quality base oils control oxidation and sludge to keep engines clean and efficient. 

Signature Series has 50 percent more detergents1 to help keep oil passages clean and promote oil circulation. It provides 90% better protection against sludge2.

1 vs. AMSOIL OE Motor Oil 
2 Based on independent testing of AMSOIL Signature Series 5W-30 in the ASTM D6593 engine test for oil screen plugging as required for the API SN PLUS specification.   
*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for use in the applications shown.

Cold-Temperature Performance is not Just Reserved for Sub-Zero Conditions

Startup lubrication is directly affected by a lubricant's cold-flow ability, and the impact is felt at higher temperatures than most consumers realize. An oil’s cold-temperature performance refers to its ability to flow when the engine is cold, or below typical operating temperature (212°F), and not simply to what feels cold to humans – even some summer days can be cold to an engine.

Pour point has been defined as the lowest temperature at which a motor oil will continue to flow under prescribed conditions. ASTM D97 spells out the standardized procedure for determining an oil’s pour point. After heating it to 45°C (113°F) the sample is slowly cooled and tilted sideways every time the temperature drops 3°C (5°F). When the oil stops flowing it has reached the pour point.

AMSOIL synthetic motor oils have lower pour points and better cold-cranking capabilities than petroleum-based products. Long after petroleum oils have solidified, AMSOIL synthetic motor oils continue to flow.

The problems with cold weather go beyond this, however. Motor oils really need to be heated well above the pour point to achieve the desired pumping viscosity. Even at just below freezing (32°F), motor oil can become difficult to pump into the engine. It sits in the pan while the friction from moving parts heats the engine and conducts this heat down into the pan. As you can imagine, this lack of oil in an engine with fast moving parts has consequences. Cold-weather start-ups are a leading cause of engine wear.

AMSOIL Synthetic Motor Oils

AMSOIL Adds 700-Hour Limit to Signature Series Drain Interval

Because a motor oil’s service life can be greatly affected by vehicle operating conditions, AMSOIL provides definitions for normal and severe service and recommends corresponding drain intervals for each. One of the conditions used to identify severe service is “excessive idling.” Because this term is somewhat ambiguous, AMSOIL is adding a 700-hour limitation to its Signature Series Synthetic Motor Oil drain interval for vehicles subjected to excessive idling. In normal service, Signature Series is recommended for up to 25,000 miles, 700 hours of operation or one year, whichever comes first. In severe service, Signature Series is recommended for up to 15,000 miles, 700 hours of service or one year, whichever comes first.

More information:
AMSOIL Signature Series Synthetic Motor Oils