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Should I be Alerted If My Oil Looks Dirty?

What Your Motor Oil Color Means

Color in general shouldn’t indicate any immediate action without an oil analysis test to validate anything out of the ordinary. No, you should not be alerted if your oil looks dirty. Is that dirt? While color could indicate an issue, keep in mind oil that appears ‘bad’ has often been tested as still within it’s usefulness.  Let’s go over the considerations which need to be known.

An object’s color can reveal a lot about its condition. A brown apple? Probably not great to eat. A slice of green bread? Same. What about motor oil color? Can your eyes provide insight into your oil’s suitability to protect your engine?

Does motor oil that’s turned black require changing?

Not necessarily. In this case, the oil’s color is a sign it’s doing its job.

Oil naturally darkens during use for a couple reasons, including heat cycles. During your drive to work, your engine reaches normal operating temperature (typically 195ºF–220ºF [90ºC–104ºC]), heating the motor oil.

Then the oil cools while your car sits in the parking lot. The process repeats as you run errands over lunch and when you return home.

This continual daily exposure to increased heat naturally darkens the oil.

In addition, normal oxidation can darken oil.

Oxidation occurs when oxygen molecules interact with oil molecules and cause chemical breakdown, just like how oxygen causes a cut apple to brown or iron to rust.

Similar is when you sit in one chair all the time and eventually your ass makes it’s own shape in the chair. The chair may be slightly worn but still holds its function.

Soot also causes oil to turn black.

While we associate soot with diesels, today’s direct-injected gasoline engines can produce more soot than older diesels without exhaust-treatment devices. While individual soot particles are too small to cause engine wear, particles can agglomerate into larger wear-causing contaminants that can lead to wear before they lodge in the oil filter.

Just because the oil has darkened doesn’t necessarily mean it’s reached the end of its service life.

Motor oil contains detergent and dispersant additives designed to clean contaminants like soot and prevent them from depositing onto metal surfaces.

Oil that has turned black is an indication the additives are doing their job. You can read more about that here.

What about motor oil that looks like chocolate milk? – Now that bad!!

In this case, motor oil color does reflect performance…and oil that looks like chocolate milk is bad. Very bad.

Water or engine coolant have contaminated the oil, typically due to a head gasket leak.

We all know that water and oil don’t mix. When they combine in your engine, water droplets suspend in the oil and alter its appearance until it looks frothy or like chocolate milk.

The presence of water leads to foam bubbles, which rupture when pulled between engine parts during operation, leaving metal components unprotected against wear.

It also forms sludge, which can clog oil passages and ruin the engine. In this case, see a mechanic as soon as possible.

What if my oil looks or feels thin?

While not related to motor oil color, this is another frequent question we field from motorists.

Don’t take this the wrong way, but in this case go out to the garage and smell your dipstick.

Oil that has lost viscosity is often due to fuel dilution. You can usually smell gasoline or diesel fuel on the dipstick in such cases.

Fuel dilution occurs when gas or diesel wash past the piston rings and contaminate the oil in the sump. It reduces oil viscosity, which reduces the oil’s ability to prevent wear. It also leads to formation of harmful varnish and sludge.

Fuel dilution can occur if you idle your engine excessively or due to a mechanical defect. It’s also common in some modern direct-injected engines.

It’s important to note that no one can precisely measure an oil’s viscosity simply by looking at it or rubbing a little between their fingers.

As Oil ANALYZERS INC. manager Allen Bender likes to ask, “When’s the last time you had your eyes calibrated?”

Oil analysis in the only definitive way to determine the oil’s viscosity and whether it’s lost viscosity due to fuel dilution.

My oil feels gritty? Should I change it?

When checking oil level, some motorists like to rub oil between their fingers to check for particles.

Grit or other contaminants can mean the oil has chemically broken down, but this is unlikely, especially with a top-shelf synthetic oil.

More likely, the oil filter has filled with contaminants and unfiltered oil is bypassing the filter and circulating through the engine.

The filter is designed with a bypass valve to ensure the engine receives oil even if the filter is full.

While dirty oil is preferable to no oil, it’s not a long-term plan for success. In this case, change the oil and filter.

Trust oil analysis, not your eyes

While it’s possible to get a rough idea what’s going on inside your engine due to oil color, appearance or scent, you need to perform oil analysis to find out what’s really going on.

By chemically analyzing a used-oil sample, a qualified lab can tell you if the oil contains excessive wear particles, water contamination, fuel dilution and more. Ultimately, the report will tell you if the oil is suitable for continued use or not.

It’s a cost-effective way to get the most out of your oil change…and your engine. Check out this post to see how to perform oil analysis.

Why Buy Signature Series? Nothing Comes Close

Why Buy Signature Series?

There are many big names out there. A lot of new start-ups claiming to be the Holy Grail in engine oil. But in short, AMSOIL remains on top for one reason – the founder AJ Amatuzio wanted to provide a product where the customer can be certain he (or she) is getting what is expected.  Nothing is scaled down to improve profit margins. (There are no share holders) Simply the best and that process involves earning the highest respect from suppliers for the privilege of developing the finest finished lubricants.

Setting Standards For You to Measure From

Signature Series Synthetic Motor Oil is not only the best oil we have ever made, it’s better than any competitive oil we have tested. Advanced engine technology and the normal demands of everyday life generate extreme conditions that can challenge motor oil and engine life. Signature Series delivers the ultimate protection against everyday extremes like towing and extended idling. Don’t just take our word for it; read on for proof.

Do you drive in hot temperatures?

In testing, kept pistons clean and held oil thickening to only 6 percent, a minimal amount compared to the proposed specification limit of 150 percent4. 50 percent more detergents5 to help keep oil passages clean and promote oil circulation. Provides 90 percent better protection against sludge6.

Do you have long commutes?

30 percent more acid-neutralizing power8 than Mobil 1*, and 36 percent more than Royal Purple*, helping engines stay cleaner, longer. Reserve protection, so you can go up to 25,000 miles, 700 hours of operation or one year between oil changes, whichever comes first.

Does your vehicle have a turbocharger?

72 percent better turbocharger protection than required2 by the GM dexos1® Gen 2 specification. Achieved 100 percent protection against low-speed pre-ignition (LSPI)3.

Do you tow or haul?

75 percent more engine protection against horsepower loss and wear7.

Do you drive in cold temperatures?

66 percent better cold-temperature performance for easier starting, better fuel economy, improved oil flow and reduced wear.

Do you want extra engine protection?

Far superior wear protection compared to the competition – kept bearings looking like new after 100,000-mile test1.


1Testing conducted in an independent lab using AMSOIL Signature Series 5W-30 Synthetic Motor Oil and a leading synthetic-blend 5W-30 motor oil in Ford F-150 trucks with 3.5L twin-turbo engines. 2Based on independent testing of AMSOIL Signature Series 5W-30 in the GM turbo coking test. 3Based on zero LSPI events in five consecutive tests of AMSOIL Signature Series 5W-30 Motor Oil in the LSPI engine test required by the GM dexos1 Gen 2 specification.  4Based on the ILSAC GF-5 PLUS specification. 5vs. AMSOIL OE Motor Oil 6Based on independent testing of AMSOIL Signature Series 5W-30 in the ASTM D6593 engine test for oil screen plugging as required by the API SN specification. 7Based on independent testing of AMSOIL Signature Series 0W-20, in ASTM D6891 as required by the API SN specification. 8Based upon independent testing of Mobil 1 Annual Protection Full Synthetic 5W-30, Royal Purple High Performance 5W-30 and AMSOIL Signature Series 5W-30 in ASTM D2896. Oils purchased 05/03/18. *All trademarked names 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.

Is Starting Fluid Bad for Gas Engines?

Is Starting Fluid Bad for Gas Engines?

The simple answer: In small doses and used properly, it can be effective in hard-starting gasoline engines. But it can be bad for two-stroke or diesel engines. The real question to ask is, “Why does my engine need starting fluid in the first place?” Find out the answer, then fix the real problem.

The detailed answer: Ask five gearheads or mechanics their opinion of starting fluid, and you might get five different answers.

Some occasionally use it to help revive an engine that’s been pulled from storage. Others use it to help coax a stubborn engine to life on a frigid morning.

Yet others won’t touch starting fluid. One mechanic I talked to blamed starting fluid for ruining the bearings in a two-stroke outboard motor. Its owner, the story goes, liberally sprayed starting fluid into the intake when the engine wouldn’t start. And sprayed. And sprayed.

Starting fluid typically contains ether, which is an effective solvent. In this case, the starting fluid likely washed the inside of the engine clean of oil, allowing metal components to contact and eventually seize.

Diesel engines, too, can suffer the effects of starting fluid. Their high compression can cause the fluid to ignite too early, effectively causing pre-ignition, which invites all kinds of problems, like catastrophic piston or rod damage. Plus, it has no lubricating properties, so it can hasten piston wear.

With minimal work, you can find all sorts of cautionary tales on the Internet of people blowing up engines after using too much starting fluid.

Starting Fluid Does Sometimes Work

Given the disdain many harbor toward starting fluid, why would anyone use it?

Because it can be effective in gasoline engines – especially carbureted engines – when used as directed.

For gasoline to combust, it must first be vaporized. The fuel injectors in your car or truck do a great job of completing this task.

In carbureted engines, fuel is vaporized as it’s forced through the tiny openings or nozzles in the carburetor. But carburetors don’t vaporize fuel as effectively as fuel injectors. Plus, gasoline doesn’t vaporize as readily when it’s cold. Anyone who’s started a carbureted car on a frigid morning knows this all too well. Plus, an engine requires more gas in the fuel/air mixture at startup, making a cold engine doubly difficult to start and keep running.

Starting fluid, on the other hand, does readily ignite in the cold, helping to start the engine and generate heat to more easily vaporize the fuel.

But a little goes a long way. Many of the problems with starting fluid can be attributed to operator error rather than the fluid itself.

In short, if you have to use starting fluid, use it sparingly. If a couple short bursts of spray into the intake don’t elicit a cough or two from the engine, emptying the can isn’t going to work, either.

No amount of starting fluid is going to revive an engine with a dirty carburetor. Identify the real problem and get it fixed.

Ask yourself this…

Instead, ask yourself why the engine needs starting fluid in the first place. There’s likely a bigger problem that needs fixing.

I was presented with this exact scenario last fall when my snowblower refused to start. So I reached for a can of starting fluid and gave the intake a shot. She sputtered a few times and quit. I repeated the process a few times, with the same result.

I should have used Quickshot when it was sitting right there when I last filled the tank. Would have solved this issue all together.

Eventually, I took apart and cleaned the carb. She roared to life on the first pull after that. In my case, emptying the entire can of starting fluid into the engine wouldn’t have done a thing, aside from washing the oil from the cylinder and causing wear. At the very least, it helped me diagnose what the problem was not: lack of spark or bad compression.

Bottom line: Starting fluid can help start a stubborn engine, but follow the directions and use it sparingly. If a little bit doesn’t work, a lot likely won’t, either. If your engine is consistently hard to start, find out why and get the real problem fixed.

Racing Oil vs. Regular Oil: What’s the Difference?

Why not use Racing Oil in my Car If It’s Tougher?

When deciding if racing oil is right for their vehicles, gearheads and other enthusiasts sometimes offer this line of reasoning:

  1. Racing engines are more severe than my engine
  2. Racing engines use racing oil
  3. Therefore, I should use racing oil in my vehicle for best protection

It’s true that your average racing engine creates operating conditions more severe than the average passenger car engine.

However, that’s not to say that modern engines aren’t tough on oil.

The turbocharged, direct-injection engines in modern vehicles generate increased heat and contaminants compared to their predecessors. Motor oil bears the brunt of the added stress.

That’s why industry motor-oil specifications keep growing tougher and automakers are increasingly recommending synthetic oils to meet these strict performance specs.

Scott Douglas AMSOIL racing truck

Scott Douglas AMSOIL race truck

Should I use racing oil in my car?

Racing, however, is a whole different animal.

The powerful, modified engines in racing vehicles produce extreme heat and pressures your average car or truck simply will never see.

A 900-hp Pro 4×4 race truck can produce engine temperatures in excess of 300ºF (149ºC). Engine temperatures in a typical passenger car/light truck fall somewhere between 195ºF and 220ºF (90ºC – 104ºC).

The difference is even more striking when you consider that the rate of motor oil oxidation (chemical breakdown) doubles for every 18ºF (10ºC) increase in oil temperature.

The tremendous shearing forces the oil bears as it’s squeezed between the interfaces of the pistons/rings and cam lobes/lifters pose another problem. The pressure can tear apart the molecular structure of the oil, reducing its viscosity and film strength.

Racing oil has to be formulated differently to protect these demanding engines. Even so, it doesn’t mean you should order a case of AMSOIL DOMINATOR®  10w-30 Synthetic Racing Oil for your car.

DOMINATOR® 15W-50 Racing Oil

Racing oil is changed more often

So, why not use racing oil in your daily driver? For starters, racing oils are changed frequently.

Most professionals change oil every couple races, if not more frequently. For that reason, racing oils are formulated with a lower total base number (TBN) than passenger car motor oils.

TBN is a measure of the oil’s detergency properties and its ability to neutralize acidic byproducts. Oils with longer drain intervals have higher TBNs.

AMSOIL Signature Series Synthetic Motor Oil features a TBN of 12.5 to enable its 25,000-mile/one-year drain interval.

In contrast, DOMINATOR Synthetic Racing Oil has a TBN of 8 since we recommend changing it more often. As great as it performs on the track, DOMINATOR is not what you want in your engine when you’re driving thousands of miles and several months between oil changes.

Regular motor oil is designed to provide additional benefits

You also want to use an oil in your daily driver that excels in several performance areas:

Motor oil additives produce many of these benefits. For example, anti-oxidant additives fight increased heat and extend oil service life.

Anti-wear additives interact with the metal surfaces of engine parts and guard against metal-to-metal contact.

Many additives form layers on metal surfaces. That being the case, they compete with each other for space, so to speak, like pigs competing for room at the trough.

Racing oils are often formulated with a heavy dose of friction modifiers to add lubricity for maximum horsepower and torque.

The boosted level of additives meant to increase protection and performance during a race doesn’t leave room in the formulation for additives found in passenger car motor oils that help maximize fuel economy, fight corrosion or improve cold-weather protection.

In effect, the ravenous pigs at the trough leave no room for their brethren, resulting in a less well-rounded formulation.

Bottom line: use regular motor oil in your daily driver

Achieving the tasks of a passenger car motor oil requires a finely balanced formulation. Too much or too little performance in one area can negatively affect other areas – and the oil’s overall protection and performance. The list of tasks required of a racing oil, however, is much shorter.

The right tool for the right job is an axiom with which you’re familiar. The same holds for motor oil. It’s best to leave racing oil to competition engines and use a properly formulated passenger car motor oil for your daily vehicle.

All You Need To Know About Motor Oil Cold Flow

Winter (Cold) flow wear factors in your engine

Engineers agree that most engine wear occurs during cold starts. While the exact percentage depends on several factors and is difficult to define, the reasons include the following…

  • A richer air/fuel mixture at startup washes oil from the cylinder walls
  • Condensation forms inside the engine that causes rust and corrosion
  • Cold piston rings and cylinders don’t seal as well, causing combustion gases to “blow by” the rings and contaminate the oil
  • Gravity causes much of the oil to fall back into the oil sump, leaving components unprotected
  • Cold oil doesn’t flow immediately at startup, temporarily starving the engine of oil

While all these factors are important, lack of oil due to poor cold-flow properties is the biggest culprit. Fortunately, there’s something you can do about it.

“Cold” isn’t just for winter

First, it’s important to define a “cold” start. While true that oil thickens more in sub-zero winter weather and causes increased starting difficulty, an engine is considered “cold” after it’s sat long enough to cool to ambient temperature, typically overnight. Even in warm climates, cold-start wear is a problem.

The oil inside your engine cools as it sits overnight. As it cools, its viscosity increases (it thickens). When it’s time to start your vehicle in the morning, the thicker oil doesn’t flow through the engine as readily as it does when it’s at operating temperature. It’s during this time that vital engine parts can operate without lubrication, increasing wear.

The problem is more pronounced the colder it gets, particularly if you’re using conventional motor oil.

Waxes solidify in the cold

Conventional lubricants contain paraffins, or waxes, that solidify when the temperature drops. These waxes cause the oil to thicken. In the comparison shown here, we cooled a conventional oil and AMSOIL Signature Series 5W 30 Synthetic Motor Oil (ASL) to -40ºF. The conventional oil on the left thickened so much it barely flowed from the beaker. If that oil were inside your engine on a cold morning, it could prevent the crankshaft from spinning fast enough to start the engine, leaving you stranded. Even if the engine started, you wouldn’t be out of the woods. Thick, cold oil can fail to flow through the tiny screen openings on the oil pickup tube (see facing page), starving the engine of oil for several vital moments before the oil begins to heat up and flow throughout the engine.

In addition, thick oil can fail to flow through the tiny passages in the crankshaft to lubricate the main bearings. Similar oil passages in the camshaft ensure the engine’s upper end is lubricated (see facing page). The further away from the oil pump these oil passages reside, the longer it takes the oil to reach components at startup, placing your engine at increased risk of wear.

Poor lubricant cold-flow properties can also affect variable valve timing (VVT) systems. Engines equipped with VVT have solenoids with tiny openings through which the oil flows and acts as a hydraulic fluid to actuate VVT components. The solenoid pictured to the right, from a Ford* 3.5L EcoBoost* engine, contains openings .007 inches across – about the thickness of two sheets of paper. Oil that fails to flow through these tiny passages reduces VVT performance and can trigger a check-engine light.

Here’s how to protect your engine

AMSOIL synthetic motor oils provide better cold-flow properties than conventional oils. Our synthetic base oils don’t contain the waxes inherent to conventional oils. As a result, they demonstrate reduced pour points and provide increased fluidity during cold starts. This translates into oil that flows almost immediately through the oil pickup screen and other tiny oil passages when you start your engine, protecting it against wear.

Look at the oil’s pour point to gauge its ability to flow quickly at startup, typically reported on the oil’s data bulletin. Pour point is the coldest point at which an oil will flow. Lower values equal improved cold-flow and maximum wear protection. AMSOIL Signature Series 5W-30 Synthetic Motor Oil, for example, provides a pour point of -50ºF (-58ºC).

Pique prospects’ curiosity

This type of information can help you create curiosity about AMSOIL products and lead someone from not looking for lubricants to looking for AMSOIL products. Ask pointed questions or provide useful information, such as…

  • Most engine wear occurs during cold starts. Do you take steps to guard against start-up wear?
  • Even in warm climates an engine is considered “cold” after it’s sat overnight.
  • Do you ever have trouble starting your truck on cold mornings?

Once they’ve shown interest, offer more technical explanation if required and offer AMSOIL synthetic motor oil as a solution to difficult cold starts and accelerated cold-start wear.

A little known fact

The differences in brands comparing a 5W-30 to the protection of a 10W-30 or 0W-30 can even be critical to the prevention of wear in the 50 to 65 degree F range. So just because you may live in a southern climate doesn’t mean you are in the green with a older specification viscosity.. A more advanced oil brand allows you to take advantage of the tech of the latest (lowest allowable) start-up viscosity year round.