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By 2020 it’s estimated that U.S. drivers will have endured 8.3 billion hours of stop-and-go driving conditions. Heavy traffic doesn’t...

June 26, 2018

By 2020 it’s estimated that U.S. drivers will have endured 8.3 billion hours of stop-and-go driving conditions. Heavy traffic doesn’t just tax your sanity, it takes a toll on your engine too.


Most engine wear occurs while idling or driving at low speeds under cooler engine temperatures. Stop-and-go traffic, warming up a vehicle in the winter and the extended idling common to commercial vehicles are all common situations that can accelerate wear.

How Temperature and Speed Affect Wear

Engine components expand and contract with changing temperatures. Cylinders and pistons are only perfectly round when an engine is at optimal operating temperature. When your engine is running but is not up to operating temperature, tight tolerances can cause wear. At slow speeds your oil pump isn’t moving as much oil through the system, further increasing the risk of wear.

The Sequence IVA Engine Test

The Sequence IVA Test was developed to simulate the stresses commonly placed on the engines of taxis, delivery vehicles and commuter service vehicles. It measures the ability of crankcase oil to control camshaft lobe wear. Worn or damaged cam lobes can lead to a loss in efficiency, increased engine noise and expensive, large-scale repairs. The Sequence IVA Test is a great metric for assessing an oil’s level of wear protection – the top concern among enthusiasts.

Test Parameters 


1994 Nissan* KA24E inline 4-cylinder, 2.4L


100 hourly cycles, 50 minutes at idle and 10 minutes of elevated rpm


Camshaft lobe wear – each camshaft lobe is measured in seven

locations near the nose of the lobe where pressure is highest.

All scores are then averaged to determine a final score.


Stop-and-go driving conditions (short trips and extended idling)


Maximum average cam wear limited to 90 µm (micrometers)

Signature Series Vs. Engine Wear

AMSOIL Signature Series Synthetic Motor Oil develops a strong fluid film that keeps metal surfaces separated, while its robust anti-wear additives further reduce wear in metal-to-metal contact regions for maximum engine life. We submitted the lightest viscosity in the line, Signature Series 0W-20, to further increase the severity of the 100-hour test. AMSOIL Signature Series Synthetic Motor Oil provided 75 percent more engine protection against horsepower loss and wear1 than required by the Sequence IVA Engine Test, extending the life of vital components like pistons and cams.

1Based on independent testing of AMSOIL Signature Series 0W-20, in ASTM D6891 as required by the API SN specification.

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