What Causes Engine Oil Oxidation?

As you might expect, oxygen causes engine oil oxidation.

Oxygen comprises about 20 percent of our atmosphere. It’s the third most common element in the universe. Without it we’d all be doomed.

And yet too much of it can cause problems inside your engine.

What is oxidation?

Oxidation occurs when the addition of oxygen changes a chemical substance. Take an apple, for example. Everyone knows that oxygen will quickly cause a cut apple to turn brown. Or metal. Oxygen can cause rust to form on some metals in a matter of days. Have you ever noticed your brakes grinding after having left your car sit for a couple days in wet weather? That sound is your brake pads scouring rust from the rotors.

Motor oil isn’t immune to oxidation. As oil reacts with oxygen, a permanent chemical change occurs that causes oil molecules to lose one or more electrons. This can result in several problems, including…

  • Formation of sludge and deposits that reduce engine efficiency and increase the risk of engine failure
  • Increased oil viscosity, which reduces fuel efficiency
  • Additive depletion, reducing the oil’s effectiveness
  • Accelerated degradation, causing you to change oil more often

Heat accelerates oxidation

Every 18ºF (10ºC) increase in temperature doubles the rate of oxidation. That doesn’t bode well for motorists driving modern turbocharged vehicles that create increased heat compared to older vehicles.

Heat isn’t the only oxidation accelerant – certain metals, acids and water can also hasten oxidation. So can large volumes of entrained air, known as foaming.

Can we prevent motor oil oxidation?

Unfortunately, no. Nature is a relentless force, and all motor oil will eventually oxidize to some degree. But we can dramatically slow oxidation through use of synthetic base oils and quality oxidation-inhibitor additives.

AMSOIL synthetic lubricants are formulated using base oils with a saturated molecular structure, meaning oxygen is prevented from attaching. This provides inherent heat and oxidation stability compared to unsaturated conventional oils.

And, because AMSOIL synthetic lubricants don’t contain contaminants like conventional oils, their base composition doesn’t accelerate oxidation.

AMSOIL synthetic lubricants also contain high-quality oxidation inhibitors. These additives are sacrificial in nature, meaning they’re designed to deplete over time. Because AMSOIL synthetic lubricants have inherently better oxidation resistance, their oxidation inhibitors last longer since they don’t deplete as rapidly.

What’s that to me?

That all adds up to a motor oil that…

  • Lasts longer despite intense heat and stress
  • Helps keep your engine cleaner and more efficient
  • Saves money in the long run through reduced maintenance

So, while oxygen lets you breathe, AMSOIL synthetic motor oil lets you breath easy since your engine is protected against oxidation.

18Dec 2018
gun range hearing protection

What’s the Best Hearing Protection for the Gun Range? Mark Nyholm|Jun 28, 2018 11:28 AM Summer weather is finally here, at least for us in the northern half of the U.S. and Canada. The longest day of the year, June 21 – the summer solstice – has come and gone. As someone pointed out to me, […]

18Dec 2018
viscosity increase

AMSOIL Synthetic Diesel Oil Greatly Outperforms Minimum Standards Shell* recently announced that a sample of “Mobil Delvac 1300* Super 15W-40 did not meet the passing limits for either API CK-4 performance standards, nor the more stringent requirements for Volvo*, MACK* and Cummins*.” The 360-hour Volvo T-13 test measures both oxidation and Kinematic Viscosity, indicating an […]

18Dec 2018

OE 0W-16: Light and Strong A 0W-16 viscosity motor oil may seem exotic to North American drivers, but as fuel efficiency requirements increase, it may become a common recommendation of manufacturers worldwide. Japanese engineers have long experimented with ultra-thin motor oils, and 0W-16 has been in regular use in Japan since the 90s. The Benefits […]

17Dec 2018

I’m going to start posting all the short comments from customers here in the Testimonial category. There may not be any photo or long descriptions or paragraphs but just a simple comment.. So one of the AMSOIL dealers in our group (Denver area) owns a repair shop which specializes in Audi/ VW / Porsche BMW/Mini. Ernie […]

12Dec 2018
Thick Foam cleans glass better

Introducing the Three Newest AMSOIL Products Jamie Jarvi|Aug 08, 2018 1:28 PM AMSOIL is well-known for its products that protect the internal parts of an engine. But you may not know about our products that protect the outside of your vehicles and equipment, too. Hot on the heels of the revolutionary new SEVERE GEAR easy-pack, we’re excited […]

10Dec 2018
differential oil in a easy pack or squeeze pack

The New SEVERE GEAR Easy-Pack Enthusiasts pride themselves on finding their own solutions to tough problems. When there’s no manual, they roll up their sleeves and make it work. But even the most inventive gearhead inevitably throws down an oily rag and wonders why the process has to be so difficult. Changing gear lube is […]