As car owners, exhaust smoke is something we are all familiar with and we have all seen oil additives that claim to stop it.
Oil additives are substances added to the engine oil to increase the lubrication. They change the viscosity of the oil, ensuring the engine runs smoothly.
We have hand-picked the best oil additives to stop smoke for you and have included a review of each.
There are 4 main colors of smoke to look out for, and this article will give you a quick run-down of what they mean, what they are caused by and what to be worried about.
We have also included a Buyers’ Guide to ensure you know what to look for in oil additives and at the end is an FAQ section.
Oil additives are added to your engine oil to improve the longevity of the engine as well as its performance. This is done by reducing the oil lost in the engine that causes the smoke to appear.
Smoking exhausts are a common issue in cars, and suddenly catching a glimpse of smoke in your rear-view mirror as you’re driving along can cause people to panic.
The first issues to focus on are when the smoke is coming out of your car, your engine type, what the smoke looks like and the smell. While in newer and well-maintained cars smoking is rarely a serious issue, it is always worth getting a qualified professional to look over your vehicle if you have any concerns.
In a hurry?
If your engine just can’t wait any longer, we’ve put our top pick here for you.
We have chosen Bar’s Leaks Engine Repair.
The product is designed as a one-stop engine repair in a bottle and has overwhelmingly positive reviews on Amazon.com. It reduces oil consumption and engine noise while improving the performance of worn engine parts. The product also restores lost compression and power.
OUR TOP PICK
OUR TOP PICK
Bar’s Leaks has been an established company for almost 70 years and this experience shows in the quality of their products.
Many reviews on Amazon.com hail Bar’s Leaks Engine Repair solution as a lifesaver for old cars on their last legs.
The company clearly displays safety information, specification sheets, a user guide and a user manual on Amazon and their own website, instilling trust in the product. The product is not solely designed to fix smoke but instead the entire engine.
Bar’s Leaks understand that cars and their inner workings decline with age and this product has been designed to keep the engine going for as long as it can. It works to prevent oil pressure and compression losses through repairing seals within the engine.
As a consequence of this, it will reduce the engine noise and increase your fuel mileage, saving you even more money in the long run.
- Multi-purpose product
- Easy to use
- Compatible with all types of engine oils
- Should see results within 100 miles
- EPA certified
- Contains zinc
- No Cons
The main reason Liqui Moly Oil Smoke Stop is so low down on our list is due to the cost.
At $21.99 for only 10fl.oz. the value for money is not here. It is designed to act primarily against blue smoke by improving the motor compression.
The product is made in Germany, the home of BMW, and the culture of automotive experience is reflected in the product quality. The additive is based around a superior viscosity index improver material and keeps working over a longer period of time to keep the oil viscosity high.
The product is suitable for gasoline and diesel engines and works via the valve guides and piston rings. The product size is sufficient for 4-6L engines, however you are likely to need multiple units for larger engines.
- Designed specifically for blue smoke
- Suitable for all engine types
- Works to improve oil viscosity
- Extends service life of catalytic converters
- High cost and low quantity
Described by some as a lifesaver in a bottle, Rislone’s Ring Seal Smoke Repair is designed to solve problems causing blue smoke.
At only $13.99 it is reasonably priced if you only require one bottle. Engines over 6L will need a dilution of 1 bottle per 5L of engine oil.
This product is not only for use on cars and can be used in 4-Stroke ATV, motorcycles and other small engine vehicles. For these engines it is recommended to use around 100ml per liter of oil.
Rislone’s product contains high-shear polymers that regain the lost engine compression by sealing the pistons and rings. The product acts to prevent build-up in the crankcase caused by blow-by - a common issue found when there are small internal engine gaps caused by wear.
The product is suitable for use in hot and cold temperatures and with conventional, high kilometer and synthetic engine oils. It clings to the surface of metal and creates a protective coating to keep the oil flow good in all weather conditions.
- Reduces oil burning
- Stops blue smoke
- Compatible for all engine types
- Larger engines may require more than one bottle of oil additive
The WYNNS Stop Smoke for Oil product is the most expensive of our choices, coming in at $31.05 for just under 12oz..
It is designed specifically for issues with exhaust smoke and acts at high temperatures to improve the viscosity of the engine oil.
Like the other products in this list, the WYNNS oil additive seals gaps in the engine and improves compression and general engine performance as a result. The WYNNS product ensures a strong protective film of oil even in high temperatures, helping to keep your engine going for longer.
It can be used in a variety of engine types, making it a good choice if you have the money to spend. Not only is it a solution to smoke-related issues, it can be used as a preventative measure to help your engine.
It has also been shown to be effective in older engines where the worn parts are beginning to struggle.
- Designed specifically for smoke
- Suitable for petrol, LPG and diesel engines
- Effective for older engines
- The most expensive of our picks
The Bardahl 2117 No Smoke + StopLeak is a 2-in-1 product designed to stop oil leaks and reduce smoke while restoring compression to the engine.
The Bardahl is the cheapest of our picks at $7.99 for a 16fl.oz. bottle.
The product restores pliability to the engine seals, while sealing the empty spaces to reduce friction overall. As a result of this, the product also reduces the noise of lifters and the engine. The seals created act to lower the engine’s emissions, reducing the number of pollutants released into the environment.
Bardahl says it is easy to use and will save you a costly trip to a mechanic if the problem is not too serious. It is proven effective on old engines in stopping smoke. The product is very thick and does not work with all engine types, but many people say it is a cheap and useful fix.
- The cheapest of our picks
- Seals leaks and stops smoke
- Decreases engine noise
- Effective on older vehicles
- Not compatible with all engine types
Best Oil Additives to Stop Smoke Buying Guide
Cause of the smoke
White smoke usually comes out when the engine is first heating up due to a release of water vapour which condenses and turns into steam.
If this smoke disappears as the engine has heated, there is unlikely to be anything of concern. If the smoke is thick and continues to emit from the exhaust, there is likely an issue with the coolant in the car leaking into the engine. This may only be a minor leak, but it is important to repair quickly as leaving it can cause total engine failure and potentially could result in having to purchase a new engine.
Black smoke coming from a petrol engine is a result of excess fuel being combusted. The first remedy for this is replacing the air filter, found in a black plastic case in the front of the engine bay. If this is not the solution, the problem should be checked over by a mechanic as it could be a more serious issue with the fuel injectors and pressure regulator.
In diesel cars, black smoke can be caused by unburnt diesel and soot build-up in the diesel particulate filter from consistently driving at low speeds. Driving faster (at about 70mph) may dislodge some of the soot due to the increased speed of the fuel and air moving through the engine.
Gray smoke is commonly caused by too much oil burning in the engine, but could also be related to an issue with the positive crankcase ventilation (PCV) in the engine. The purpose of this is to pull unburnt fuel from the lower regions of the engine to the higher ones to reduce emissions. The PCV will naturally wear out over time, and it is fairly easy to repair.
Automatic cars emitting gray smoke could be an indication of a transmission fluid leak in the engine and should be looked over by a professional immediately as this can lead to big issues.
The final smoke colour is blue, often emitting a burning smell at the same time. This is an indication that there is oil somewhere in the system that it is not meant to be. This can be caused by excess oil being added to, or spilt on, the engine during an oil change. If the smell and smoke stop after a little while this is likely the cause and there is no reason to panic.
Particularly in old cars, blue smoke can be a signifier that the piston rings or valve seals have worn out and will need to be replaced for the car to continue running. An easy way to check whether the oil is being burnt is looking at the car’s dipstick and seeing if the levels are going down faster than usual.
Like petrol and diesel only go in certain engines, not all oil additives are suitable for use in both types of engine.
It is important to consider what type of fuel your car runs on prior to purchasing oil additives as purchasing the wrong type for your engine could cause issues with its perfomance.
A good place to start is the owner’s manual for your car, as the manufacturer will make it clear what is okay to use. The internet also has lots of helpful websites if you are still unsure.
Some oil additives cannot withstand being stored in temperature extremes and this is an issue for people living in more variable climates.
When purchasing an oil additive you should check the storage instructions as incorrect storage can lead the additive to perish and could cause issues with your engine. It is also important to ensure the oil additive will be effective at high temperatures as car engines get very hot, especially on long drives.
It is important to know the chemical composition of oil additives as these can have other effects on your car engine.
Common chemicals in oil additives are phosphorus and zinc which aid engine performance. Zinc is highly suited to older engines as it works to help performance. Phosphorus reduces the friction in the engine by limiting the metal-to-metal contact and will help to improve the longevity of your engine.
Many oil additives will have an EPA (Environmental Protection Agency) certification. This means that the additive works to reduce the fuel emissions in the car and in turn makes the car more eco-friendly and more fuel-efficient. The certification serves to prove there are no harmful chemicals in the product.
We have selected a range of cost prices for you here, but it is an important aspect to consider when choosing an oil additive.
If you have a small engine then it is not such an issue but for vehicles with larger engines, or if you own multiple cars, the cost of oil additives can quickly run up. While still cheaper than a trip to the mechanic, it’s always worth putting in the time to save some cash.
Other benefits of the oil additive
Oil additives are rarely designed with one goal in mind and so most products offer a variety of benefits to your vehicle.
The three most common are reducing friction, reducing fuel consumption and inhibiting rust formation.
The lubricating effect of most oil additives reduces the friction between the sheets of metal in the engine and helps to prolong engine life. Your fuel consumption per gallon should decrease by about 1-2 miles per gallon following an oil change or two as the engine is under less stress. You should look for additives that prevent corrosion and rust as well to get a good bang for your buck.
Frequently Asked Questions
What are oil additives?
They are a chemical compounds that are added to engine oil (base stock) to increase lubrication of the car’s engine.
They have three main roles - enhance the desirable qualities of the base stock, suppress the undesirable qualities and add new, useful qualities. Oil additives usually consist of a mixture of antioxidants, corrosion inhibitors, demulsifying and anti-foaming agents, pour-point depressants and viscosity index improvers.
They add new properties to the base stock via the incorporation of expreme pressure additives, tackiness agents, metal deactivators and detergents.
How often do I need to change my oil?
Years ago the official advice was every 3,000 miles, but as engines have improved the advice has changed.
The AAA today recommends changing it less, only every 5,000-10,000 miles. This is because changing engine oil often results in run-off into natural water sources and polluting the water supply. Changing the oil less frequently will not only save your engine and the environment but your wallet too.
Can oil additives hurt my engine?
If you do not research correctly, there is the possibility that cheaper oil additives could harm your engine.
As a general rule, if you have properly researched the oil additive and checked that it is compatible with the make and model of your car/engine, there is little chance that oil additives will harm your engine in any way. They generally improve engine efficiency and quality.