Want to know the inside scoop on some of today's most notorious oil myths within the automotive world? Well we've got you covered. Select a myth from the pull-down below, and we'll give you nothing but the facts.

Oils from paraffin-based crude are loaded with wax and create engine sludge, varnish and/or engine deposits.


There are two basic types of crude oil, naphthenic and paraffinic. Most conventional engine lubricating oils today are made from paraffinic crude oil. Paraffinic crude oil is recognized for its ability to resist thinning and thickening with temperature, as well as its lubricating properties and resistance to oxidation (sludge-forming tendencies). In the refining process, the paraffinic crude oil is broken down into many different products. One of the products is wax, and others are gasoline, kerosene, lubricating oils, asphalt, etc. Virtually every oil company uses paraffinic base stocks in blending its conventional engine oil products.

Many people believe the term paraffinic to be synonymous with wax. Some have the misconception that paraffinic oils will coat the engine with a wax film that can result in engine deposits. This is not true. The confusion exists because paraffinic molecules can form wax crystals at low temperatures. In lubricating oils, this wax is removed in a refining process called dewaxing. Wax is a premium product obtained from crude oil and to help us produce the highest-quality base stocks available, Quaker State® uses base stocks with the minimum amount of wax possible. The end result is a motor oil product formulated with premium lubricating base oil.

Myth: Oil Color

You can tell the condition of oil by the look, smell or color of it. And if it turns dark or black quickly, it’s no good.


Nothing could be further from the truth. If the oil is doing its job of cleaning the engine, then it should be dirty when it is drained. Quaker State® motor oil will start looking dirty a short time after it is put to use. In the case of diesel engines, the oil may look dirty within a few hours of operation. These are signs that the motor oil is doing its job of keeping soot, dirt and other combustion contaminants in suspension to be carried to the filter or removed from the crankcase when the oil is changed. Quaker State motor oils have been formulated to hold these contaminants in suspension until they can be removed with an oil and filter change.

Using a synthetic motor oil will void a manufacturer's warranty.


Using synthetic oil will not interfere with the warranty coverage as long as the synthetic product meets the viscosity and performance requirements outlined in the vehicle’s owner’s manual. In fact, many new high-performance vehicles come with synthetic oil from the factory.

You can't switch from synthetic oil to conventional oil or mix the two.


You may interchange synthetic and conventional oil as long as the synthetic motor oil product and conventional motor oil product meet the viscosity and performance requirements outlined in the vehicle’s owner’s manual. Synthetic blends, in fact, are a mixture of conventional and synthetic-base oils.

New or rebuilt engines need to be “broken in” with non-detergent, non-synthetic oil.


With today’s technology of oils and engine manufacturing, engine manufacturers no longer recommend the use of non-detergent oils for the break-in period. In fact, engines today come factory-filled with high-quality GF-4/SM performance motor oil, which contains high levels of detergents and dispersant additives.

Thicker motor oil is better for your engine and increases engine life.


Instead of talking about why thicker oils are not ideal, let’s talk about why thinner oils are the preferred choice. The main reason vehicle manufacturers recommend thinner or lighter viscosity grades of motor oil is because a gain in fuel economy may be achieved with lower viscosity oil in an engine designed for the lower viscosity oil. Lower viscosity oil may help reduce internal engine friction because it takes less energy to pump the thinner oil throughout the small passages inside an engine. Some vehicle manufacturers are struggling to meet Corporate Average Fuel Economy (CAFE) requirements set by the government. Any fuel mileage improvement associated with a lubricant would be good for them, and lighter viscosity grade motor oil will make a difference.

A thinner motor oil is also essential for easy starting, particularly in cold weather, and for proper lubrication once the engine starts. Thinner oils enable more fuel economy than thicker oils; this is why OEMs specify them. Thinner oils, such as SAE 5W-30, will flow faster than heavier motor oils during start-up and initial engine operation, and will help protect the engine. The viscosity grade(s) recommended by the vehicle manufacturer depends somewhat on engine design. Engine manufacturers have spent considerable time and expense experimenting with different viscosity grades and have indicated in the owner's manual the grades they feel will best protect the engine at specific temperatures. While one manufacturer's engine may require an SAE 10W-30, another manufacturer's engine may require an SAE 5W-20 viscosity grade. This is likely due to different tolerances within the engine or other engine design factors.

All 2-cycle oils are the same.


Generally, 2-cycle oils formulated specifically for air-cooled engines, such as chain saws, may contain additive chemistry not recommended for water-cooled engines, such as outboard motors. Ensure that the product you use meets the equipment manufacturer’s requirements. Some oil companies formulate individual products to meet both water and air-cooled engine requirements.

You can’t use motor oil in a manual transmission.


Fluids recommended for manual transmissions/transaxles vary from manufacturer to manufacturer and are dependent upon application. The type of fluid recommended for a given unit will depend on a number of variables, which include the low-temperature fluidity required, the amount of gear wear protection needed, the effects of the fluid on synchronizers and the transmission/transaxle. Some transmission manufacturers may require motor oil to be used in the manual transmission. Other fluids used may be ATF (automatic transmission fluid), gear oil or a special manual transmission fluid, depending on variables previously mentioned. Always check the owner’s manual to ensure the fluid being used meets the proper performance requirements.

Motor oil and ATF are the same oil.


Motor oils and ATFs are formulated differently. Motor oil is formulated to withstand the harsh combustion environment of an engine and reduce friction, while ATF is formulated to provide specific frictional properties for a transmission.

Adding a quart of ATF to your engine the day before an oil change will clean the engine due to the high levels of detergent in ATF.


ATF is not formulated to withstand the combustion environment inside the engine. Quaker State® recommends that you keep the fluids where they belong: motor oil in the crankcase; automatic transmission fluid in the transmission.

If owner’s manual states my car requires API SF quality oil, I can’t use API SM quality.


Using motor oil that meets the automobile manufacturer’s warranty requirements is a key factor in developing repeat customers and safeguarding against unhappy customers with damaged engines. With all the changes in engine designs and oil formulations, determining which engine warranty requirements a given oil meets can be a frustrating experience.

The API engine oil classification system is divided into two major categories. The “S” category designates oils for gasoline passenger car engines, and the “C” category designates oils for diesel-powered commercial truck engines. The “S” series is composed of SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL and SM. SM oils provide higher levels of performance than all the other “S” oils. Oils labeled SM can be used in older engines that once required older API categories.

I don’t drive under severe conditions, so I can follow the manufacturer’s recommendation for “normal service” and go longer between oil changes.


Even with the best oil, after a while the additives are depleted and the oil becomes too dirty to function effectively. Because most drivers operate under severe-service conditions, Quaker State® recommends using the severe-service interval recommended in your owner’s manual. The time limit may come before the mileage limit. Your vehicle owner's manual specifies the correct oil-change intervals for the car—under both normal and severe-service conditions.

The automobile manufacturers set their oil drain intervals based on laboratory engine test results, fleet test results and used oil analysis results. They also base intervals on the assumption that the consumer will follow recommended preventive maintenance practices and maintain proper oil levels. Thus, Quaker State recommends oil and filter changes according to the manufacturer’s recommendation.

Bulk oil is of lower quality than bottled oil.


Consumers may believe that bulk oil is of lower quality than packaged product because the price is generally less expensive. However, with Quaker State® motor oil, our bulk oil is the same high quality as our packaged product. The only difference is the size of the container—and the cost savings you realize in paying for one large container instead of multiple quart bottles.

Adding oil additives means you can extend drain intervals and engine life.


Engine oil technology has rapidly advanced in the past decade, making today's high-quality engine oils second to none. Now, vehicle owners have a choice between conventional, synthetic blends and full-synthetic engine oils positioned to provide the best protection for their application and driving needs. However, there are consumers who want to provide value-added protection to their engines through the use of engine treatments. Although there are several engine oil supplements on the market today, consumers must remember that the Original Equipment Manufacturers (OEMs) have stated in the vehicle owner's manuals (i.e., 1999 Chevrolet Silverado page 6–15), "Don't add anything to your oil. Your dealer is ready to advise if you think something should be added."

The wrong oil can cause the dipstick to rust.


Not true. Generally, rusting of engine parts indicates neglected maintenance or a severe-service environment that requires more frequent oil-change intervals. All high-quality motor oils are formulated to help protect against rust and corrosion. However, to maintain that protection, the oil and filter must be changed according to the recommended maintenance intervals.

Jason's Myth: Coolant Leak

A coolant leak is present only if the fluid separates into two parts.


When coolant contaminates engine oil, high fluid temperature will cause the water portion of the coolant to evaporate, leaving the ethylene glycol portion of the coolant behind. This results in a loss of lubricity of the engine oil product and sludge forming within the engine. Severe cases of coolant contamination or a neglected internal engine coolant leak could lead to complete engine failure.
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