AMSOIL vs. Mobil 1* Performance

AMSOIL Signature Series and Mobil 1 are two of the best motor oils, but is one better?

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Signature Series Synthetic Motor Oil
David Hilgendorf
by David Hilgendorf
February 15, 2023

Enthusiasts love to modify their vehicles to make more power. Lists of top-10 mods often include turbocharging, supercharging, nitrous, performance exhaust, upgraded intake, engine tuning and more. But they rarely mention upgrading your motor oil to protect your engine from all that additional power.

Let’s discuss the risks of boosting performance and take a closer look at how two of the best premium motor oils perform: AMSOIL Signature Series and Mobil 1.

Horsepower on a sheet of paper

Your engine – and all the time, money, and effort you’ve poured into it – rely on the protection of an oil film that’s thinner than a sheet of paper. Adding horsepower increases engine stress, which places even more stress on motor oil.

Many enthusiasts upgrade the crank, pistons, cam and bearings as part of their build, to better handle the additional pressure. Yet, they often overlook the necessity of upgrading the motor oil to support and protect all this additional expensive equipment.

The shear importance of oil

Viscosity is the most important property of oil, as it indicates the oil’s ability to flow. Engine upgrades can increase mechanical shearing forces, which result in viscosity loss. Shear occurs when one layer of oil moves in the opposite direction of another layer of the same oil. A notable example occurs between the piston and cylinder wall. These two oil films move in opposite directions under intense heat and pressure. This is why high-horsepower, high-rpm engines create increased risk of viscosity loss due to shear.

Shear tears apart the molecules of the oil’s additives, which are meant to expand the viscosity range of the base oil. The application and type of base oil determine the type and amount of viscosity additives required. Some viscosity improvers resist shear better than others. And some synthetic oils don’t need viscosity improvers at all due to their inherent ability to withstand shear.

When oil loses viscosity due to shear, it can fail to provide wear protection between moving parts. Think of the force transferred through the piston, rod and crank to the thin oil film protecting the bearing. There’s not much room for error.

AMSOIL Performance Testing

Laboratory tested and proven on the road.

See how AMSOIL products perform in the lab and in the field.

Check out the tests

AMSOIL vs. Mobil 1

AMSOIL synthetic motor oil uses naturally shear-resistant base oils combined with top-tier, shear-stable viscosity improvers that withstand extreme heat and shearing forces. Not only does AMSOIL exceed industry standards and outperform competing brands, it fights viscosity breakdown 46% better than Mobil 1. It’s built to stand up to the devastating effects of high-horsepower, modern engines and provide maximum protection.

Volatility and cleanliness

A clean engine is a more efficient, longer-lasting engine. After pouring your time and hard-earned money into building your dream vehicle, you expect it to last. Volatility is an oil’s tendency to evaporate in the presence of extreme heat. Powerful, modified forced-induction engines built to shred pavement also create intense heat, which can cause inferior oils to breakdown and leave harmful engine deposits that reduce performance. An oil’s total base number (TBN) is a measure of its ability to neutralize harmful acids that lead to engine deposits.

AMSOIL vs. Mobil 1

Again, AMSOIL comes out on top, fighting volatility 38% better than Mobil 1.

And in TBN testing, AMSOIL delivered 28% more acid-neutralizing power than Mobil 1, to help your engine stay cleaner, longer.

If you’ve already upgraded to Mobil 1 from conventional oil, congratulations on choosing a high-quality motor oil for improved engine protection.

However, test results show that AMSOIL Signature Series Synthetic Motor Oil provides even better protection against viscosity breakdown, volatility, acid and deposits.

Why wouldn’t you give your high-performance engine the superior protection of AMSOIL Signature Series Synthetic Motor Oil?

by David Hilgendorf

AMSOIL Technical Writer and 20-year veteran of the motorcycle industry. Enjoys tearing things apart to figure out how they work. If it can’t be repaired, it’s not worth owning.

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Signature Series Synthetic Motor Oil