Adding Additives

INSTANT EXPERT

In today’s cost-conscious times, supplementary additives promise means of cutting motoring costs but Rob Marshall studies whether you should dismiss them, or not.

Since the motorcar was invented, aftermarket companies have offered all sorts of potions, pledging to increase reliability and/or reduce running costs. Some of them delivered on their promises; others fell notably short. Yet, it would be unfair to judge additives used by our forebears as totally useless. Some of them were necessary, so much so that separate dispensers at petrol forecourts used to be popular. These upper cylinder lubricants reached the areas that oil alone could not and helped discourage carbon build. Refinements in engine design particularly rendered such additives redundant – or have they? The fact that additives have not just disappeared but have become more prolific indicates that their relevance has grown, rather than diminished.

Modern engines bring new problems and quality additive manufacturers are rising to the challenges.

Additives: The modern significance

While modern power units are more fuel efficient, more powerful and cleaner than their ancestors, these advantages come at a cost. Reduced internal tolerances make them less tolerant to contaminations, which build as the vehicle ages. Furthermore, cars have become considerably more complicated, particularly with the proliferation of exhaust emission after-treatment systems. For these reasons, inhibiting and removing contamination build is the main aim of automotive additives.

One would expect manufacturers to endorse additives openly; but they do not. An explanation may be purely brand protection. As regular readers appreciate, taking carmakers’ advice is not always in our best interests, especially where maintenance intervals are concerned. Experienced DIYers are, quite justifiably, suspicious of the official recommended engine oil change rates that tend to be too long, especially for sealed-for-life lubricants that are used in transmissions. Of course, CM readers’ definitions of what constitutes ‘life’ is likely to be more ambitious than that of car manufacturers, one of which revealed to us that it was seven years – a figure that is well below the current average car age in the UK.

Of course, additive manufacturers are vying for your hard-earned cash, which would make some readers suspicious of them. We should also consider that additives do not have to fulfil any formal technical specifications – unlike manufacturer-approved lubricants, for instance. While this fact might explain car manufacturers’ caution, it also means that you should buy with care.

Older cars relied on upper cylinder lubricants for optimum engine life. Regular use of fuel system cleaners helped to remove residues left behind by evaporated petrol.

ADDITIVE TYPES

 Additives of all varieties can be split into two categories. First, those that promise enhanced running, be that power/fuel efficiency advantages, or preventative maintenance. The second type is geared towards solving a problem, offering a faster-acting solution to rectify a fault, instead of extensive dismantling and/or component replacement. As with any product, decide on your aim, first.

Keep That Engine Alive.©

CONTAMINATION  WHAT IS THE PROBLEM?

 The 2019 World Fuel Charter says: “The conformity of modern engines with their specified performance in terms of power, fuel consumption and emissions over time will depend largely on the cleanliness of their injectors”.

Contamination, therefore, is the antithesis of economical and reliable motoring. These undesirable deposits sap power, waste fuel and reduce mechanical life. Yet, fuel injectors are not the only affected components. Ironically, the need to make exhaust emissions cleaner has led to modern engines becoming dirtier internally, one reason for which is that they are forced to ingest and treat their own excreta.

As these contaminations continue to build as the vehicle ages, engine efficiency drops. In turn, this accelerates deposit build until a failure occurs, or an engine Management Indicator Lamp illuminates. Further consequences of contamination build include higher emissions and fuel consumption, lower performance and even an increase in noise levels.

Many additive manufacturers, therefore, have focussed their efforts on identifying, loosening and removing accumulated contamination, while discouraging future build. Using a decent additive correctly and in the appropriate situations can help reduce fuel costs and repair bills.

Pour-in fuel additives

The most consumer-friendly types are those that are poured into the tank. Many additive companies report that these products are their best sellers and demand has risen in recent years. This has not been down to clever marketing alone but valid technical reasons. Changes to petrol and diesel formulations have made them more prone to leaving post-combustion deposits behind. These alterations have been made not just for environmental reasons, such as reducing the emissions of Volatile Organic Compounds and increasing the bio-fuel content, but also to ensure as much fuel is cracked as possible from each barrel of crude oil. Further complications with these blends include lower lubricity and a greater tendency to absorb moisture.

Therefore, fuel system cleaner additives are formulated to perform many functions and a huge variety of products are available at varying price points. Some types optimise the fuel, by enhancing its lubrication qualities and increasing the octane (petrol), or cetane (diesel) ratings. Others focus more on reducing oxidation/ ageing rates, ie. the speed at which the fuel reacts with the air and deteriorates. All these benefits should result in cleaner combustion. Additives can perform these tasks only to the fuel to which they are added. However, products that focus on cleaning should also soften existing carbon deposits and, in the case of diesel especially, help to kill microbe growth that can clog fuel lines.

Products advertised as fuel injector cleaners focus more on cleaning these delicate parts, thus avoiding the need for relatively expensive and inconvenient removal and specialist ultrasonic cleaning. Yet, even this additive class is fragmenting. As gasoline direct injection (GDI) offers lower fuel consumption and CO2 emissions, compared to the earlier port/indirect petrol injection designs, where the injector was placed within the inlet manifold behind the valves, it has created other issues. As these fuel injectors are relocated within the combustion chamber, they are exposed to not only the heat but also the byproducts of the combustion process,

Additive value

 Lucas Oil’s ‘Core 4’ is a good option for first-time additive users. It features four of the US oil and lubricant manufacturer’s best-selling products:

Transmission Fix Power Steering Stop Leak Upper Cylinder Lubricant (UCL) Heavy Duty Oil Stabilizer

Transmission Fix smooths out problems, such as worn bands, leaking seals and high operating temperatures.

Power Steering Stop Leak

does what it says. UCL is the fuel additive solution for borderline diesel/petrol engine emission test failures. Heavy Duty Oil Stabilizer fortifies engine oils and protects against dry starts by leaving a thin protective coating on all moving parts.

Overdosing additives can cause major problems, especially with DPF regeneration fuel additives that are added into the tank. Power Steering fluid is subjected to very high pressures and heat. It degrades rapidly and cannot protect the pump gears and the seals. Some additives are available to support the fluid but buy with care. In addition, choose a decent quality fluid. Industry tests, such as ASTM D6186 (Oxidation Induction Time of Lubricating Oils by Pressure Differential Scanning Calorimetry), will validate which power steering fluids are up to the job. Like those used in engine oil, flushes are beneficial for the cooling system too – helping remove scale and boost efficiency.

TYPES OF CONTAMINATION

 Combustion produces deposits that accumulate within the engine and its intake/exhaust systems as the years pass and mileages rise. They tend to comprise: 1. Sludge. Most readers will be familiar with this soft, black deposit (as pictured), especially as it can build most obviously within the valve covers.

Within the engine, sludge results mainly from oil oxidisation, caused by neglected oil changes, higher temperatures and/or further contamination from moisture, coolant, or fuel. 2. Varnishes/lacquers. Like sludge, both contaminations result from oil (or fuel) oxidisation. Yet, they become baked to the surface and can be extremely stubborn to remove. Lacquer is a harder deposit than varnish but both strike not the engine but also fuel injectors, especially direct injection types that are exposed to the combustion process. 3. Soot/carbon. Known otherwise as ‘particulates’, these acidic carbon deposits are caused by imperfect combustion.

Ironically, Gasoline Direct Injection (GDI) petrol engines produce more soot than earlier port-injection designs.

Exhaust Gas Recirculation systems reduce in-cylinder temperatures to kerb NOx emissions, but they also raise soot emissions. On diesels, the soot is captured by the Diesel Particulate Filter (DPF) and, on more recent petrol engines, by the Gasoline Particulate Filter (GPF). A major task of engine oil is to keep soot particles in suspension and stop them from forming lumps and causing blockages.

causing contaminations to become baked to the injector tip. This restricts the injectors’ fine nozzles, each of which possesses a smaller diameter than human hair, which alters the delicate spray pattern. Thankfully, sophisticated engine management will compensate for this injector fouling, by adjusting the fuel trim automatically but only to an extent. Once the long-term fuel trim deviates beyond a typical 25% from its standard setting, the engine malfunction indicator lamp is likely to illuminate – an instant MOT failure issue on most modern cars.

JLM Lubricants reports that additive technologies and means of testing them must keep up with engine development. When the company tested its GDIspecific injector cleaner at the Millbrook Proving Ground in Bedfordshire, it found that fuel consumption was reduced by 4% and deposit levels within the intake manifold and behind the inlet valves did not increase.

While detergents are vital to clean varnishes and gums from pistons and injectors, one has to consider that some of these fuel additives end up in the engine oil, because a small quantity of exhaust gases bypass the piston rings. BG Products reports that, if the product used contains unstable cleansing chemicals, they can reduce engine oil life and increase the risk of sludge build. Interestingly, the Worldwide Fuel Charter warns against cheap fuel additives specifically, because they can leave extra deposits behind. Therefore, when looking at fuel additives that perform cleaning functions, check for ingredients that are effective against promoting additional deposits, such as PEA (polyether amine).

Some fuel additives are more bespoke. For classic cars, the advantages of fuel additives that combat valve seat recession are a priority for cars with iron cylinderheads, especially. While the absence of lead in today’s petrol blends is not an issue for modern vehicles, last year’s increase in ethanol levels in petrol (up to 10% for 95RON) creates several complications. While corrosion is not so much of a problem for most post-2010 cars, E10 oxidises relatively quickly and a car running on fuel that has ‘gone off’ will not run at its optimum and the fuel will promote extra deposit build. Supplementary additives are designed to counteract the downsides of ethanol-laced petrol and help the fuel to last longer. They are ideal for low-mileage users, or those using plug-in hybrids mainly in electric-only mode. LIQUI MOLY, for instance, reports that its Fuel Protect additive is useful to combat the water-absorption qualities of modern ethanol-laced petrol, because it binds the water in the petrol, in addition to its corrosion protection benefits.

DO ADDITIVES WORK?

 Establishing whether additives work depends largely on the result you desire. Your expectations should also be reasonable. An additive that helps rejuvenate the active surfaces of a catalytic converter, for instance, cannot be expected to repair a smashed monolith. Similarly, an Exhaust Gas Recirculation carbon cleaner spray cannot repair an EGR valve with a head that has separated from its stem.

While additives are still subject to basic consumer rights law, their formulations are set by their manufacturers, which consider not just their effectiveness but also user safety and, of course, price.

Independent testing is involved, lengthy, costly and likely to be inconclusive. Therefore, after deciding your aims, research the available products. Those from a well-known brand, supplied by trustworthy outlets, are more likely to meet their claims than spurious alternatives, sourced from unknown sellers’ shops on marketplace websites. Products, aimed at garages, can be a good quality indicator, because the motor trade will ditch products quickly, if they are found to be ineffective.

Conduct your research carefully and be prepared to ask the additive manufacturer questions. Be suspicious of any company that points solely to its hundreds/thousands of ‘satisfied’ customers on online review sites as justification for its product’s efficacy, instead of technical evidence.

Keep That Engine Alive.©

Fuel additives for the MOT

While using additives to clean fuel injectors and keep fuel fresh for as long as possible will help to suppress exhaust emissions, you may look to additives as a relatively inexpensive means of bringing a borderline MOT emissions failure back from the brink. Should the tester think that a petrol engine’s catalytic converter is not working as it should, consider that its honeycomb-like monolith structure could be saturated with carbon, so its previous metal catalysts cannot react with the exhaust gases. Some additives, such as that promoted by Cataclean, are dosed into the fuel, pass through the engine and the resultant post-combustion vapours eradicate the contamination build, restoring the converter’s efficiency levels.

The range of fuel additives for diesel particulate filters (DPF), however, is more complex. For the uninitiated, these units are soot traps, built within the exhaust system, that capture and vaporise carbon particulates under high temperatures, preventing them from being expelled into the atmosphere, using a process called ‘regeneration’. Unfortunately, DPFs can become overwhelmed with soot, caused mainly by low speeds, short distances, or a fault, such as a split turbocharger hose. Yet, should a DPF-related fascia lamp appear, consider whether there is a fault at all. Many cars display a dashboard light (or message) that warns of a potential problem, which can be resolved by driving the car at a consistent higher speed, until the lamp extinguishes. This gives the DPF sufficient time and temperatures to complete the automatic regeneration process. This advice should not be ignored.

Some technically-minded owners reckon that a DPF blockage can be solved with brief full-throttle applications and high engine speeds. Alternatively, some experienced DIYers (and garages) resort to ‘forced generations’, where a DPF cleaning programme is enacted diagnostically with the car stationary. Based in Ashington, Northumberland, the DPF Doctor network head, Darren Darling, reports that these techniques invite further mechanical damage; far preferable are mechanically-sympathetic, gentler methods.

Additives have a vital role to play in this kinder approach. The most widespread types of DPF fuel additive are regeneration aids. JLM Lubricants reports that additive formulations must evolve, as chemical technology advances. While its ‘Regen Plus’ additive reduces the temperature at which the soot within the DPF burns, the company has reformulated it, by replacing its iron ingredient with cerium. Aside from being more effective, the main advantages include making DPF damage less likely, should it be overdosed slightly.

When poured into the diesel tank, the active additive constituents survive the combustion process, enter the DPF and permit the soot to vapourise at a lower temperature. Yet, Mr Darling reports that these products can cause more harm than good, if used incorrectly. Presuming that more additive means a faster and superior result, some car owners do not follow the instructions and over-dose the fuel tank deliberately. While the soot is burnt, the DPF internals overheat and collapse. Last August, for instance, the DPF Doctor network reported over 200 DPF blockages, caused not by soot but disintegrated internals. In severe cases, the DPF outer casing can melt, causing red hot particles to drop onto the ground, creating a fire risk.

Therefore, when considering a fuel additive to facilitate DPF regeneration, determine what you are trying to achieve and read the instructions carefully. To work properly, the procedure may not be as straightforward as adding a bottle of additive to a tank of diesel and driving off.

Should the DPF become overloaded with soot, it may be too late to use a regeneration additive, because of the overheating risk. Professional on-car cleaning methods may involve injecting different additives into the DPF directly, via the hollow pressure differential tubes, which soften and dissolve carbon within the DPF. Yet, even garages must monitor DPF temperatures during this operation. Powerflow Ltd, for instance, which distributes the North American BG Products range of additives to the UK, reports that it supplies professional DPF cleaning machines only to technicians that employ DPF temperature monitoring equipment throughout the cleaning procedure. Therefore, when taking your car to a garage with a DPF blockage, provide the technician with as many truthful details as possible, including any DPF additives that you have dosed into the tank, from where you fill with fuel, your driving patterns and when the vehicle was serviced last.

The delicate monolith within catalytic converters is coated with precious metals that react with the flowing exhaust gases. If coated with carbon, this vital interaction cannot occur, and polluting exhaust emissions will increase.

Some fuel additives perform multiple functions. These include increasing the fuel’s octane/cetane rating, while offering contamination removal and corrosion control. Such products are ideal for frequent use. Fuel additives that focus on contamination removal are useful for relatively infrequent use, such at every service, or if erratic running is noticed. More concentrated additives might be considered in the event of a fault but use them with care.

Keep That Engine Alive.©

 Fuel injectors are precision

parts and must be kept clean. Direct Injection (including petrol GDI) engines work at very high pressures within hostile environments and are highly sensitive to any deviation in fuel atomisation, which can result from contamination deposits.

Image courtesy of Delphi

 Should the fuel tank not

be replenished at least once every fortnight, consider using an additive that extends fuel life. These include fuel system driers and those that assist with biofuel degradation.

While modern fuel additives cannot be poured directly into the intake, such as that pictured earlier on an older carburettor car, some additives that are designed more for professional use can be dosed directly into the fuel filter housing. However, ensure the product you use is designed to be used at such a high concentration, without causing harm. A method used by professional workshops is to plumb a dedicated additive dosing machine into the fuel filter inlet and outlets using a set of adapters, thus isolating the fuel system from the fuel tank. Pictured is an arrangement used by Terraclean.

ONBOARD FUEL ADDITIVES

 Aside from some LPG converted cars being fitted with an automatic dosing system that dispenses a valve-seat protector additive, the most common automated fuel additive system is equipped to certain diesels, to reduce the temperatures at which soot particulates burn within the DPF. This not only makes the system less prone to blocking but it gives manufacturers freedom to mount the DPF further away from the hot engine.

The system comprises a separate tank that tends to be situated adjacent to the diesel tank beneath the car (pictured). Alternatively, a replaceable pouch may be used instead. These contain a fuel additive (the trade name of which is ‘Eolys’) that is dispensed into the fuel tank, soon after the diesel is topped-up. The quantity is assessed by a separate additive ECU that relies on inputs from the fuel level and fuel cap presence sensors. Just like the DPF regeneration additives mentioned within this feature already, Eolys works by surviving the combustion process and coating the resultant soot with a coating that burns at a lower temperature. When these enveloped particulates enter the DPF, the coating burns first and the resultant temperature rise vapourises the soot.

The system is surprisingly reliable but most issues occur when the additive needs replenishing. While the driver is warned by a dashboard message about the additive level running low, consider that most (if not all) systems especially do not possess an additive level sensor. Instead, the quantity of additive dispensed is measured and these counters require resetting diagnostically after the tank is replenished. Where fitted, additive pouches can be bought and refitted fairly easily but filling the tank is more involved.

While not refilling the additive tank, or doing so with diesel, is certain to promote a future DPF soot blockage, we have been made aware of ‘fake’ aftermarket additives being offered to both the public and the motor trade.

CDTi (the maker of PatFluid, an aftermarket alternative to Eolys branded additives) has become aware of such products being offered at very low prices. To find out more, the company submitted them to an external laboratory to evaluate how much active material they contain that permits them to work. Compared to the Original Equipment additives and PatFluid, the results showed that some of them contained less than half of the active material. Worryingly, many of them contained fewer than 90% of these essential ingredients. CDTi told CM that these low levels mean that they are unlikely to work effectively at all.

 Modern cars suffer from intake manifold

contamination, especially those with direct injection. The amount of contamination is not always obvious, because the fuel injection system will adjust the fuel trim to compensate but efficiency will be compromised. To save extensive dismantling, you can try to remove and inspect an intake sensor. This temperature sensor on this diesel is contaminated with a gungy mixture of oil and soot, emanating from both the crankcase ventilation and exhaust gas recirculation systems.

 Some additive aerosols are designed to be

sprayed into the inlet with the engine running. Follow the instructions carefully. It is a slow process, because the product must be applied in short bursts, so it does not accumulate, ‘pool’ and cause an excessive quantity to enter as a liquid, rather than in an atomised form.

You may decide to clean the MAF sensor but use a suitable product that is designed for the purpose, as some intake cleaner aerosols can leave a residue behind that could prevent it from working properly afterwards.

 Various EGR cleaning methods

are available, some of which require the engine running. Generally, EGR valves can be considered worn out, once they have covered around 80,000 miles and so do not waste time cleaning one. Renew it instead.

 EGR coolers can also block with

soot. Again, various on and off-car additives are available to loosen and remove the carbon. Should you notice a falling coolant level, check that this heat exchanger is not responsible. It is easy to confuse EGR cooler failure with that of the engine head gasket.

 If you can scrape out sludge with a

finger, consider not using additives. Instead, it may be simpler, quicker and cheaper to remove the inlet manifold and ask a garage to soak it in its parts wash overnight. The manifold must be completely dry internally before refitting. Always fit new gaskets.

 On diesels, you

may decide to spray an intake cleaner through the EGR pipe aperture on the manifold. Again, follow any instructions carefully and consider that spraying intake additives into the engine can be performed as an annual maintenance procedure, prior to an oil change, not solely in the event of a fault.

 Before fitting the manifold, you may

wish to clean the intake ports, using the EGR/inlet additive spray and a lintfree cloth, and/or an old toothbrush. Use the product sparingly and allow sufficient time for it to evaporate.

Keep That Engine Alive.©

 Some professional garages

employ inlet manifold machines that use various cleaning additives that pass through the manifold and into the engine, as it runs at idling speeds.

 A major problem with direct

injection vehicles is contamination build restricting not just the air supply but also valve movements. Direct injection petrol (GDI) cars suffer more from this latter problem, owing to the higher temperatures baking the sooty and oily sludge into a harder, rubbery deposit.

 Intake cleaning additives seem

not to be sufficiently strong to loosen and remove this deposit. So far, the main accepted way of dealing with the problem is to use specialist equipment to inject crushed walnut shells under pressure into the cylinder-head intake port, with the valves closed.

Engine oil additives

Perhaps the most popular additive that DIYers consider is engine oil flush. This is dosed into the engine oil, just before draining the sump, to dissolve any accumulated contaminations and hold them in suspension, so they flow out after the sump plug is unscrewed. Some car owners worry that a flush will dislodge larger deposits and cause blockages. They have a point. Though, this situation tends to be caused by solvent-based flush products that dominate the UK market. Therefore, seek out a solvent-free flush, which is also more likely not to degrade oil seals.

In addition, check the Safety Data Sheet and ensure that the “Flash Point” ASTM D-93 is at 50°C, or below. This will reassure you that any oil flush product that remains in the sump will evaporate out of the new oil and not contaminate it.

Should you own a GDI car, consider that the low-tension piston rings, which are designed to reduce internal friction, can become gummed with deposits surprisingly early in the car’s life. This reduces compression, leading to inefficient combustion and increased crankcase blowby, all of which increase contamination build at the top and bottom of the engine. A further issue is the engine oil being tainted with fuel, leading to increased oxidisation and sludging risks. A good quality oil flush helps to remove these deposits and restore the rings’ compliance and sealing qualities.

Some additives treat bespoke problems. This Revive Turbo Cleaner product, for instance, is designed to address sticking turbocharger variable vane geometry parts.

 The loosened deposits are then

vacuumed out, along with the walnut shells. If paying to have this work done, do not forget to have the intake manifold and EGR systems cleaned, too.

Oil fortifiers

The Verification of Lubrication Specifications (VLS), the independent British organisation that checks whether, or not, the claims made by lubricants are true, warns that the smallest change in the formulation can have a real impact on the performance of the oil. It highlights to CM readers that,

“Aftermarket engine oil additives risk interfering with the lubricant’s ability to cool, clean, protect moving parts and emission control devices, which could result in unnecessary expense to customers”

LIQUI MOLY, however, produces both engine lubricants and additives and it reassures users that:

“Our additives are fully compatible with every common engine oil. If applied correctly, our additives cannot negatively affect the chemistry of the engine oil. As there are no standards for additives, it might be that products from competitors interfere with the formulation of the oil but definitely not ours.”

Keep That Engine Alive.©

Perhaps unsurprisingly, additive companies insist that their fortifying products enhance the oil’s protective qualities. Yet, perhaps we should consider that oil blenders could formulate superior oil but, to do so, they would have to raise prices. BG Products reasons that several aspects of engine oil performance can be improved beyond current standards and highlights its balanced package of additives that do just that.

We should also consider that oils suffer a premature increase in viscosity and contamination, when exposed to extreme conditions. Such situations include high temperatures, long periods of idling/stop-start driving, and multiple cold runs. In these cases, dosing specific additives into the lubricant, such as antioxidants, acid neutralisers, detergents, and anti-wear metal protectors will enhance the oil’s life, hypothetically.

Before buying any oil fortifier, BG Products recommends that it should be evaluated to see whether it benefits the lubricant, or ruins it, because of a reckless addition of disproportionate, or low-quality ingredients. For instance, a hot topic in classic car circles is ZDDP, an anti-wear additive that is not so prolific in modern car engine oils, due to the damage it wreaks on catalytic converters. One might think that adding more ZDDP as possible to oil is ideal, but this stance may be counterproductive, by causing the oil to sludge.

BG Products highlights that its Advanced Formula MOA and Diesel Oil Conditioner additives contain fortifiers that are well-researched, with solid science behind them to prove that they enhance the engine oil’s performance, without upsetting its chemical stability. JLM Lubricants states that its Bortec oil additive raises the stock lubricant’s protective qualities, while neither interfering with the engine lubricant’s basic chemistry, nor clogging the oil filter. However, rather than relying on ingredients used by its competitors, such as molybdenum disulphide, JLM Lubricants has chosen boron nitrate, which can tolerate temperatures three times higher than those more traditional additives, without sacrificing its protective qualities significantly. The additive also ‘clings’ to metallic surfaces, permitting extra protection on coldstarts, as the oil pressure builds. This is especially relevant, because most engine wear occurs on start-up. LIQUI MOLY has chosen a slightly different direction with its Cera Tec additive, which utilises ceramic particles. Tests performed for the company at the automotive engine test centre, APL in Germany, showed that engine oil wear protection rates double, when fortified with Cera Tec.

LIQUI MOLY anti-wear additives range starts with physical protection (Oil Additiv), which utilises molybdenum disulphide particles that adhere to the metal surfaces. Should physical protection not be desired, Motor Protect offers a chemical alternative that uses friction modifiers to smooth the metal surfaces. Combining the two technologies is the aforementioned Cera Tec that employs ceramic particles for its solid lubricant instead of molybdenum disulphide.

Naturally, you can select engine oil additives to fulfil a specific purpose. On engines that are prone to emitting a brief mechanical rattling after a cold start, one might wish to consider an additive that will address this oil starvation issue. Many people report positive experiences using Lucas Oil’s Heavy Duty Oil Stabilizer on engines with a tendency for slow oil pressure build but the original formulation is too ‘thick’ for modern engines. Fortunately, the company has responded with a lowviscosity alternative for current models.

Minor oil leaks can be cured with a seal-swell additive, apart from those

Should you suspect severe contamination, consider that physical removal and cleaning may be the only option. This engine sump pan contained several centimetres of congealed sludge within its base.

It is not always easy for companies to test products, even independently. To prove that its K-seal could seal holes that could empty a cooling system in around 20 minutes, Kalimex sought to prove compliance with ASTM D-3147. Yet, with no test facilities in the UK, or North America, the company had to engage Brighton University to build a test rig. The result proved K-seal’s compliance. LIQUI MOLY's DPF Protector is added before filling the tank with new fuel. Add every 1000 miles, or so. It is useful especially for vehicles that are used for short tips or city driving.

Adblue is a distilled water/urea additive, which is vital on Euro VI diesel cars. It is not a fuel additive but is dispensed into a separate tank, from where it is injected into the exhaust system, when required. Never use AdBlue that has reached its expiration date and never overfill the tank. In some cars, this damages the additive ECU. This tank shows AdBlue overflow, evident by the white crystals.

caused by physical damage, such as a punctured seal. However, this product will act on all rubber components indiscriminately, such as valve stem oil seals. This is one reason, why engine seal-swell additives must never be used in automatic, or dual-clutch automated manual gearboxes, because they will swell all of the hydraulic seals as well.

Several additives exist to help prolong a highly worn engine, many of which thicken the oil to help enhance oil pressure. Such additives should be used with care and with consideration about whether the additive will help to cure the issue(s) experienced, such as excessive crankcase pressures. Whichever engine oil additive you choose, ensure that it will not increase deposits within the catalytic converter, or DPF.

TerraClean urges the need for diesel particulate filter cleaning

 With constant attention being paid to air quality and emissions control, the need for a clean diesel particulate filter (DPF) has never been higher, says decarbonisation expert TerraClean.

Staying on top of maintaining the DPF can prevent longer-term issues arising, such as turbocharger failure, caused by increased back pressure, and failure of the MOT on emissions. Cleaning blockages of soot from the DPF is also far cheaper than a full replacement.

With 500 service centres across the UK, TerraClean provides a unique decarbonisation technology to reduce vehicle emissions and fuel consumption and improve performance.

To find your nearest centre, visit

www.terraclean.co.uk

PROFESSIONAL vs RETAIL PRODUCTS

 You may discover additives from the same brand being marketed to car owners in retail shops that differ from those being offered to the motor trade. The most obvious difference is the labelling. Consumer product labels tend to be more informative for the average car owner and the additive is less likely to result in damage, if used incorrectly. For example, pouring a consumer-grade petrol fuel injector cleaner into a diesel fuel tank is unlikely to cause serious harm. This may not be the case with a professional product.

Products that are used by garages may be quicker acting because, in an environment where time is money, fast results are needed. This means that the formulations are either different to the retail alternative, or more concentrated. However, professional products tend to be less user-friendly to handle and the consequences of overdosing, for instance, could be more serious.

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