Are engine oil additives effective?

There are two reasons why a car needs engine oil: first, it reduces friction by lubricating the engine to keep it running smoothly, and second, it prevents it from rusting. Engine oil additives promise so much more, including increasing your mileage, lowering your emissions, repairing your transmission, and even reviving an old engine to make it as good as new. But just how effective are they, and does your car need them? 

Photo by Malte Luk


No for newer cars, Yes for older engines

Engine oil additives are mixed with engine oil to make it work better, but this depends on the additive, the oil, and your car engine. If your car is new, its engine won’t need additives for problems that additives are typically supposed to solve. Newer car models are also obviously improved over time, and new engines are made with dispersants that clean up the gooey carbon mess that would build up in older engines. These more modern engines are also enhanced to prevent corrosion, so that rusting is minimized. 

Additionally, the formula of the most recently produced motor oils is already improved with additives mixed in. Simply put, engine oil additives are not necessary for newer cars. However, older cars would benefit from engine oil additives, but, again, depending on what this older engine needs. 

Not all cars are created equal. Some engines are prone to rust. Some engines develop sticky carbon build up faster than others; some tend to overheat quite rapidly, some have problems starting up after being left cold. Because of this, engine oils and their additives vary according to what your engine requires, which is usually why your auto dealership will recommend you only use a particular brand of engine oil for your car. Older cars typically benefit from the right kind of engine oil additives, but the wrong one could trigger other issues. 


Find out what your car engine needs

Since you drive your car, be in tune with clues and cues. Do you have a Powerstroke engine with cold start problems? Does your motor make strange noises? Does it feel like your machine has slowed down significantly? Do you produce thick, black smoke, and are bad for the environment? Some additives target specific problems and often say so on the back of the bottle. Or you could ask your mechanic to make a recommendation. 

Also, check your car manual to see what can harm the engine. Some additives should not be used on certain engines. For example, the additive known as zinc dialkyl dithiophosphate or ZDDP does not work for engines that are not made of steel. Or your vehicle may already be upgraded to inhibit corrosion but still accumulates carbon deposits in the oil, which needs a detergent-type of engine oil additive rather than one that fights rust. 

For newer cars, spend extra on hardworking engine oil that already has some additives mixed in, and best to use the oil that your car manufacturer has recommended. Disciplined maintenance is also vital – check your oil and change your filter regularly.



Mark Munroe is the Creator and EIC of ADDICTED. He's ADDICTED to great travel, amazing food, better grooming & probably a whole lot more!