AMSOIL and the Noack Volatility Test (ASTM D5800): Why It Matters

Glowing turbocharger showing extreme engine heat, illustrating how volatility causes oil to evaporate under high temperature conditions.

Turbochargers generate extreme heat — weak oils evaporate, leaving your engine vulnerable. AMSOIL fights back with industry-leading volatility control.

Why Low Volatility Is Critical for Engine Protection

What Is Oil Volatility?

Volatility refers to how easily engine oil evaporates when exposed to high temperatures. The higher the volatility, the more oil can “boil off,” leaving less lubricant behind to protect critical components. This is especially dangerous in modern engines where operating temps and stress are higher than ever.

The more volatile an oil is:

The more frequently you'll need to top off
The greater the chance of engine deposits
The less stable the oil becomes over time

This isn't just about convenience — high volatility leads to real wear, reduced fuel economy, and shorter engine life.

What Is the Noack Volatility Test? (ASTM D5800)

To measure volatility, oil manufacturers and certification bodies rely on the Noack Volatility Test, formally known as ASTM D5800.

Here's how it works:

A precisely weighed sample of oil is heated to 250°C (482°F) for one hour
A stream of dry air passes over the sample
As lighter components in the oil evaporate, their mass is carried away and captured
The remaining oil is weighed again
The percentage of mass lost is reported as the oil's volatility rating

The lower the percentage, the more thermally stable the oil.

How AMSOIL Led the Industry

Most oil brands began using the Noack test only when it became an industry requirement. AMSOIL, however, began using it voluntarily in 1985 — decades ahead of many competitors.

Founder Al Amatuzio recognized early that real-world engine performance was tied directly to how oils performed under extreme heat. While other companies relied on outdated tests like flash point, AMSOIL adopted the Noack test to measure real evaporation losses.

This decision allowed AMSOIL to:

Prove performance under thermal stress
Design oils that last longer and resist burn-off
Differentiate themselves before synthetic oils became mainstream

Why Modern Engines Demand Low-Volatility Oils

New engines are smaller, more powerful, and more thermally stressed than their predecessors. Turbochargers, gasoline direct injection (GDI), variable valve timing, and hybrid systems all raise engine temps and pressure.

These conditions:

Cause weak oils to vaporize quickly
Create deposits in turbo bearings and ring packs
Thicken oil through evaporation (raising vyscocity)
Accelerate wear during cold starts and high load

What evaporates matters:

Light oil molecules evaporate first
What remains is heavier, thicker, and less effective
Additive concentrations become unbalanced
Your oil no longer performs as intended

This is especially critical in turbocharged or performance engines, where oil volatility directly affects power, emissions, and reliability.

Industry Volatility Limits: What the Specs Say

To control volatility across the board, modern oil specs include maximum Noack values:

Spec	Noack Volatility Limit (% loss)	ASTM D5800 Used?
API SP	≤15%	✅ Yes
ILSAC GF-6A / GF-6B	≤15%	✅ Yes
GM dexos1 Gen 2	≤13%	✅ Yes
ACEA C5 / A5 / B5	Varies (typically 13–15%)	✅ Yes
Ford WSS-M2C946-A	≤13%	✅ Yes

Important note: Meeting these specs is the minimum — not the benchmark for high performance.

AMSOIL Synthetic Oil Volatility Control Compared to Mobil 1

Once more, AMSOIL proves its superiority by outperforming Mobil 1 in combatting volatility, boasting a 38% improvement.

AMSOIL vs the Competition: Measured Performance

When AMSOIL first used the Noack test in the '80s, conventional oils had volatility loss rates of 17–25% — a huge loss of protective lubricant.

Today:

AMSOIL Signature Series: Often shows 6–8% loss
Mobil 1 (various lines): Typically 12–14%
Conventional blends: Still often test near 15–20%

This means:

AMSOIL loses half as much oil under heat compared to many synthetics
It remains within spec longer
It protects engines in towing, off-road, or turbo use where volatility really matters

Why You Might Notice Volatility Problems

You might be using a “high-quality” oil — but still topping up every few thousand kilometers or noticing sluggish cold starts.

Oil volatility could be the cause.

Symptoms of high-volatility oils:

More frequent top-offs between oil changes
Blue smoke from exhaust during hard acceleration
Engine knocking or increased noise
Poor cold start lubrication
Sticky rings and varnish buildup

These problems show up especially in:

Turbocharged gas engines
Heavy-duty vehicles idling for long periods
Performance cars used aggressively
Older engines with worn seals

🔧 Real-World Signs of Oil Volatility

Volatility isn't a lab-only problem. It shows up on your dipstick and in your repair bills.

If you experience:

Oil levels dropping between changes
Oil that smells burnt
“Check oil” lights between service intervals

…it's not necessarily your engine's fault. Your oil may simply be vaporizing too quickly.

Switching to a low-volatility synthetic like AMSOIL helps eliminate that variable. Less evaporation means longer-lasting protection — especially in hot, high-load environments.

Mobil 1 vs AMSOIL: The Volatility Breakdown

Mobil 1 is a respected name in the synthetic world, and it generally meets modern specs — but it doesn’t outperform them.

Mobil 1 Extended Performance: Tests between 11–14% Noack loss
AMSOIL Signature Series: Consistently 6–8%

That's a margin that matters, especially:

On hot summer days
During highway towing or plowing
In turbo engines operating under boost

AMSOIL doesn't just meet the limit — it exceeds it, giving you more protection, better vyscocity stability, and less oil consumption over time.

The Additive Angle: Why Stability Helps Everything Else

When lighter molecules boil off, the oil left behind isn't just thicker — it's imbalanced.

Your additive package (detergents, dispersants, anti-wear agents) was blended for a specific oil formula. If 10–15% of the oil disappears, that balance is disrupted.

That leads to:

Increased deposits in the engine
Reduced resistance to wear
Loss of fuel economy
Inconsistent protection over drain intervals

AMSOIL's lower volatility means its oil formulation stays chemically stable, not just physically present.

How to Choose the Right Low-Volatility Oil

Look for:

Noack value well below 13%
Mention of ASTM D5800 in product data sheets
Proven third-party or internal testing results

AMSOIL provides detailed Noack specs on many of its product technical data sheets (TDS). Very few brands do.

If you're running a turbocharged truck, a performance car, or a fleet of hard-working pickups, volatility control is a non-negotiable factor in oil performance.

🔗 Related Pages

❓FAQ | ASTM D5800 and Oil Volatility

What is ASTM D5800?

ASTM D5800 is the standardized method used to measure how much engine oil evaporates under high heat. Commonly known as the Noack Volatility Test, it simulates real engine temperatures to determine how stable an oil is when exposed to extreme conditions.

Why does low volatility matter?

Low volatility means less oil evaporates during operation. This reduces oil consumption, keeps vyscocity stable, maintains additive balance, and provides more consistent protection over the life of the oil.

What happens if oil volatility is too high?

Oils with high volatility can evaporate quickly, especially in turbocharged or high-heat engines. This leads to oil loss, thicker vyscocity, increased engine deposits, and reduced fuel economy.

Does volatility affect turbocharged engines more?

Yes. Turbochargers create extremely high localized heat. If oil evaporates under these conditions, it can leave critical components like turbo bearings exposed to wear and damage.

Is oil burn-off the same as volatility?

Essentially, yes. “Burn-off” is the real-world result of high volatility — the lighter parts of the oil evaporate under heat, reducing the amount of oil left to do its job.

How does ASTM D5800 relate to engine oil specs?

ASTM D5800 is the official volatility test method used by specifications like API SP, ILSAC GF-6, GM dexos1 Gen 2, and ACEA. These specs set a maximum volatility % that oils must stay under to be approved.