The original Slick-50 (pre 1984) formula is now sold under the name Xcelplus.


Q Is it true that Xcelplus is the original Slick-50 formula?
A Yes. In 1983 John Bishop the inventor discontinued the supply of  the formula to Petrolon who marketed Slick 50.

Q What other names has Xcelplus been marketed under, when were they available and where?
A Click to view Trademarks used to market Xcelplus

Q Will Xcelplus void your warranty?
A No Xcelplus will not void the manufacturers warranty.



Q Can the manufacturers of the new Slick-50 formula quote tests done with the original Slick-50 formula?
A No. The Slick-50 settlement with the FTC (Federal Trade Commission) prohibits Slick-50 from making claims that rely on the original Slick-50 tests.

Q Can Xcelplus quote tests done under the Slick-50 name?
A Yes... for any test done with the original (pre 1984) Slick-50 formula.

Q What is the difference between Xcelplus and it's competitors?
A Xcelplus is a long lasting treatment (160,000 km between treatments).
Xcelplus has been tested extensively.
Tests are provided on the web site.

Q Do you have a picture of the PFL (Permanently Fused Layer) coating?
A Yes in the Tests section (Franklin Institute and NASA)

Q Are Xcelplus claims substantiated?
A Yes. There are tests by independent laboratories, consumer and government organisations: Look in the tests section.

Q How can I test it's working?
A Do some DIY tests

Q Is pressure testing (Falex ball test) a valid way to establish which products work best?
A No. Extreme pressure additives usually contain high levels of chlorine and sulphur. Chlorine forms hydrochloric acid (HCl) and sulphur forms sulphuric acid (H2SO4) over time and damage your engine.

Q What is the best way to establish which products work best?
A Measure wear using oil analysis or a magnetic sump plug.

If wear is significantly improved so are other desirable parameters e.g. Power, economy, vibration, noise, temperature, reliability, longevity, etc...

Q If my engine is quieter does this mean a product is reducing wear?
A No. Extreme pressure additives like chlorine and sulphur make engines quieter but can damage your engine. Oil stabilisers and viscosity improvers make your engine quieter but don't always reduce wear.



Q Is Xcelplus an "oil additive"?
A No. Xcelplus is a "Metal treatment" and "Boundary Lubricant". It treats the metal not the oil and prevents metal to metal contact.

Q Does Xcelplus contain PTFE (Poly Tetra Fluoro Ethylene)?
A Yes.

Q Is PTFE the active ingredient?
A No. The manufacturer (Petrolon) says it is not and so do Dupont.

Q Why do you no longer mention Teflon in your products?
A Dupont trademarked the name Teflon (aka PTFE)

Q Is Xcelplus compatible with all metals?
A Yes

Q Can Xcelplus block my oil galleries?
A No. An oil gallery is typically at least 8 mm in diameter. Xcelplus coats to 1-2 microns (1/1000 mm).

Q Can Xcelplus interfere with engine clearances?
A No. Xcelplus coats to 1-2 microns (1/1000 mm) and this is too small to interfere with any clearance.

Q If engine tolerances are too tight, causing abnormal wear, will Xcelplus help?
A Yes. When the clearances are too tight Xcelplus provides boundary lubrication which prevents wear.

Q Why doesn't my idle speed increase if the friction is decreased?
A In modern cars the Electronic Control Unit (ECU aka computer) will keep the idle at the preset speed.

Q When will the idle speed increase?
A After treating with Xcelplus engines with carburettors normally show an increase in the idle speed.

Q If the friction is reduced why doesn't the temperature of my engine drop?
A The thermostat keeps the temperature in a pre-set range so you normally never notice any improvement.

N.B. When an engine is overheating adding Xcelplus often reduces the friction sufficiently to bring the temperature back into the normal range.

Q Can you use Xcelplus in a rotary engine?
A Yes. Rotaries respond well to Xcelplus.

Q How can you tell that soot is reduced after treatment with Xcelplus?
A a) Pre-ignition (pinging) is reduced b) Run an oil analysis c) Ignition can be advanced further d) You have more power e) Your mileage improves f) Take a look inside the combustion chamber or at the spark plug

Q Can Xcelplus stop an engine from seizing?
A Yes. However other damage can occur to an engine running without oil so we do not recommend this.



Q How much does the average car save after using Xcelplus?
A ~$840 each year ($8,400 over a 10 year period). Read 7 Ways to save money with Xcelplus for more details.

Q How long does it take for the savings with Xcelplus to pay back the cost of the product?
A ~43 days (Read Save time with Xcelplus)

Q What other savings do you make when you use Xcelplus?
A Wear, repairs, oil, protection, emissions (CO2, CO, hydrocarbons/soot, NOx, etc...) and time (Read Cleaning up the planet one car at a time)

Q How long would it take the fuel savings to pay for a bottle of Xcelplus?
A It would take you $1,000 of fuel to pay the cost of the bottle if your mileage improved by 10 % (Read Reduce wear with Xcelplus)

Q How much do you save at the fuel pump by using Xcelplus?
A Assuming an average 10% improvement in efficiency you would save $10 for every $100 of petrol purchased (Read Save fuel with Xcelplus)

Q How soon should you treat your engine?
A As soon as possible: You start saving as soon as the engine is treated (Read Protect your engine with Xcelplus)


Engine Treatment (Concentrate)

Q How is Xcelplus applied?
A The treatment is added to the oil.

Q Does the engine need to be hot prior to treatment?
A No

Q Does the engine need to be started immediately after treatment?
A No

Q Should you change the oil prior to treatment?
A Yes. The treatment will have longer to clean and coat the engine.

Q Is an oil change essential before treating?
A No. The treatment will work even if the oil is dirty.

Q If you don't do an oil change how can you maximise the treatment time?
A Add 1/2 the treatment immediately and the other half when you change the oil.

Q Can I split my treatment across two or more oil changes?
A Yes. A very dirty engine or an engine where the oil is changed frequently may benefit from this approach.

Q What kinds of engines can be treated?
A Petrol, diesel, alcohol, gas, nitrous, turbo, supercharged, carburettor, fuel injected, direct injected, etc... Do not use in 2-stroke and aircraft engines: These have special treatments designed for them. 

Q How often should an engine be treated?
A Retreat after 160,000 km. This ensures the coating remains optimal N.B. If an engine is rebuilt, parts are changed or mechanically abraded these parts will need to be retreated.

Q How long does the coating last?
A 160,000 km

Q Can the coating last for more than 160,000 km?
A Yes. However to ensure full protection we recommend retreating at 160,000 km.

Q How long does it take Xcelplus to treat the engine?
A The length of an oil change is ideal. It is recommended that the oil is not changed for at least 8,000 Km. The longer Xcelplus is in the longer it has to treat the metal. This is especially important in dirty engines where the metal has to be cleaned/prepared so the treatment can bond to the surface.

Q If a lot of carbon is mobilised by the treatment what can be done? e.g. In diesels
A Do an early oil change to remove the excess carbon.

Q How quickly can the effect of Xcelplus on an engine be noticed?
It starts treating as soon as you add it to the engine. Typically the bigger the problem the faster you notice it working.

Q How much will one bottle of Xcelplus treat?
A One bottle of Xcelplus treats an engine capacity of 7 L (not oil capacity)

Q Can you put less Xcelplus in smaller engines?
A Yes. Roughly pro-rata e.g. A 3.5 L engine would require only half a bottle.

Q Does it matter how much oil is in the engine?
A No. Xcelplus treats the metal not the oil. Treatment is based on the size of the engine (combustion chamber volume) not the oil volume.

Q Is over-treating an engine with Xcelplus dangerous?
A No. Xcelplus only coats to 1-2 microns thickness then stops. Any excess will be flushed out with the oil change.

Q If you apply the recommended amount of Xcelplus is there any chance you will under-treat your engine?
A No. The recommended amount should be more than sufficient to treat any engine up to 7 L engine capacity.

Q Will Xcelplus make the wet clutch in my motorcycle slip?
A No. The fibre plates remain uncoated and do not slip even though the metal separator plates are coated.

Q Is Xcelplus compatible with synthetic, mineral, graphite, castor and ester (vegetable) based oils?
A Yes. Xcelplus is non-polar and thus will dissolve in any non-polar solvents (oils). It does not dissolve in polar solvents (alcohols).

Xcelplus is compatible with API SF, SG, SH / CD, CD2, CE, Caterpillar TO2, Cummins NTC400, Allison C3, Mack EDK2, MIL L46152 C & D, MIL L2104 E & D

Q Is it better to treat an old car or a new car with Xcelplus?
A Both.
A new car gets the benefit of reduced wear (lasts longer).
An old car often shows the greatest improvements e.g. economy, noise, temperature, vibration, compression, power, responsiveness, etc...

Q Should you treat a brand new vehicle with Xcelplus?
A No. You should wait until the car is run in. Xcelplus will almost stop the wear-in process.

Q When is the engine run in?
A 10,000 Km is sufficient to run in most engines. However run-in distances vary so please check your service manual e.g. Small engines are usually run in sooner

Q Will Xcelplus help a smoking vehicle?
A Yes. Xcelplus removes varnish and helps the rings move more freely in the piston so they seal better. N.B. Xcelplus does not replace metal or fix worn seals.

Q Will Xcelplus increase compression?
A Yes. Xcelplus removes varnish and helps the rings to move more freely in the piston/cylinder so they seal better: compression evens out across all cylinders N.B. Xcelplus can not fix broken rings, replace missing metal or fix seals.

Q Can I use my favourite oil with Xcelplus?
A Yes. Xcelplus does not change the performance of an oil.

Q How can I tell if Xcelplus is compatible with something?
A Put a small amount of Xcelplus and your oil together and see if they mix. If they sediment or separate then they are not compatible.

Q Can you use oil additives after adding Xcelplus?
A Yes. Oil additives be safely used after Xcelplus treatment.

Q Can other oil additives be used during Xcelplus treatment?
A No. The oil additives may interfere with the treatment process. N.B. Oil additives are unlikely to affect the treatment process but it is preferable not to use them for one oil change just to be certain.

Q What effect does using Xcelplus have on oil or oil additives?
A Oils and oil additives last longer and work better

Q Can you extend the oil change intervals when using Xcelplus?
A No. We recommend maintaining manufacturer specified oil change intervals

Q Should the bottle be shaken before adding Xcelplus?
A No. Xcelplus does not require shaking to remain in suspension.

Q Can I run my engine without oil after treating with Xcelplus?
Running without oil is not recommended: Oil helps remove heat/contaminants and decreases impact forces. Tests running without oil are only to demonstrate that Xcelplus adds an extra level of protection in excess of that provided by oil or oil additives.

Q Can Xcelplus be used in hydraulics?
A Yes. Hydraulic oils are normally non-polar. Xcelplus is soluble in a non-polar hydraulic oil N.B. Use the gear treatment if gears are present.

Q Can Xcelplus be used in brake fluid
A No. Brake fluid is highly polar and the Xcelplus is non-polar: the product will not dissolve.

Q Can Xcelplus be used in water?
A No. Water is polar and Xcelplus is non-polar. Unlike substances do not dissolve in each other.

Q Will painting Xcelplus onto a surface work?
A Yes. Xcelplus will coat but in the absence of heat and pressure it will be very slow.

Q Is the Engine treatment subject to evaporation?
A No. It contains a paraffin which is extremely heat resistant.

Q Will centrifugal filtration stop Xcelplus from working?
A We recommend that you change back to standard filtration for one oil change.

Q Is there anywhere you shouldn't put Xcelplus?
A Do not use it in automatic transmissions (including CVT's), centrifugal clutches, new engines and anywhere where metal to metal friction is required.

Q How much is wear reduced after treatment with Xcelplus?
A Wear was reduced to ~1/2 - 1/5 normal. This is equivalent to a ~2 - 5x increase in engine lifespan.

Q Is Xcelplus good for Diesel Particulate Filters (DPF's)?
A Yes. Soot, hydrocarbons (HC's), other particulates and emissions are reduced after treatment.

Q What is the most visually striking result obtained after treating a car with Xcelplus?
A Oil which turned black very rapidly prior to treatment remained clear after treatment (Ford Falcon LPG 2001)

Q What is the most unexpected result obtained after treating something with Xcelplus?
A  The chain on a Yamaha XT600 suddenly became very quiet and chain life increased from ~12,000 km to 57,777 km: The OEM 520 (light) motorcycle chain was treated after 10,000 km (almost worn out) with ~1 ml of Xcelplus using via a Scottoiler (drip feed). The saving in parts was ~$1,200. 


Gear Treatment (Concentrate)

Q How much Xcelplus Gear Treatment should you use?
A Add 10 % of the oil volume

Q Can you use Xcelplus Gear Treatment in Limited Slip Differentials (LSD's)?
A Yes

Q Can you treat an automatic transmission e.g. CVT (Continuously Variable Transmission), hydrostatic transmission or centrifugal clutch with Xcelplus Gear Treatment?
A No. It may cause slippage.

Q Can you treat differentials, gear boxes, power steering and other parts with Xcelplus Gear Treatment?
A Yes. Virtually anything which uses oil as a lubricant can have Xcelplus added to it N.B. It should not be used in automatic transmissions (including CVT's) or centrifugal clutches as it may cause slippage.

Q Are there any situations in which Xcelplus does not work?
A Yes. When oil pump is not working or when the treatment is not added

Q Is there anything the Gear Treatment should not be used with?
A Yes. It should not be used with polar lubricants (alcohols) as these are incompatible. If in doubt mix the two liquids. If they fail to mix they are incompatible e.g. water is a polar liquid and will not mix

Q How does the gear treatment differ from the engine treatment?
A It is thicker. It is specifically formulated for gearboxes. It is dosed at 10% of the oil volume.

Q Can Engine Treatment be used instead of Gear Treatment?
A No. It is not optimised for the gearbox.

Q Will you harm a gearbox if you put in Engine Treatment?
A No


2-Stroke & Combustion Chamber Treatment (CCT)

Q How is the Xcelplus 2 Stroke and Combustion Chamber Treatment (CCT) applied?
A Add it via the fuel, the oil injection system or the air intake.

Q What size 2-Stroke engine does one 15 mL bottle of Xcelplus 2-stroke treat?
A Up to 750 cc

Q What size 4-Stroke or diesel engine does one 15 mL bottle of Xcelplus CCT treat?
A Up to 3.5 L

Q Can you over treat an engine with the 2-Stroke & Combustion Chamber Treatment?
A No. The treatment stops coating after 1-2 microns.

Q What can you do if you suspect you have undertreated your engine with CCT?
A Add another bottle to ensure full treatment.

Q Why do you use less CCT in 4-Stroke and diesel engines?
A Because you are only treating the combustion chamber not the crankcase as well.

Q How much petrol should you use to dilute the Combustion Chamber Treatment?
A A full tank of petrol: Higher dilution is better.

Q Is it better to treat an engine quickly or slowly?
A Treating an engine slowly will give you a better coating

Q Which treatment method works the best?
A Dilution in the fuel works very well. Oil injection also works very well.

Q Which treatment method is the simplest?
A Usually adding to the fuel is the simplest way to treat an engine.

Q Which treatment method is most commonly used?
A Dilution in the fuel is the most common method.

Q Does the Xcelplus 2-Stroke Treatment last as long as the Engine treatment?
A No. The temperatures in the combustion chamber can be as high as 1100˚C at the valve seats and this decreases the life of the treatment.

Q How long does the 2-Stroke & Combustion Chamber Treatment last?
A We don't have an exact figure for this product.

Q Why is the Xcelplus 2-Stroke Treatment also called a "Combustion Chamber Treatment"
A Because it can be used in 4-stroke and diesel engines where it lubricates the combustion chamber.

Q Can the Xcelplus 2-stroke Treatment be added via the carburettor (air intake)?
A Yes

Q Is the Xcelplus 2-Stroke Treatment compatible with model aircraft fuel?
A No. The methanol used in model aircraft fuels is polar and the 2-Stroke is non-polar: The product will sediment. .

Q Can the Xcelplus 2-stroke Treatment be used to treat model aircraft engines?
A Yes. Drip a small amount in via the air intake.

Q When is the best time to apply the treatment via the air intake/carburettor?
A When it is not possible to apply it via the fuel or oil injection e.g. On LPG only engines

Q When applying the treatment via the air intake how can you avoid fouling the Mass Air Flow (MAF) sensor?
A Apply the treatment after the MAF sensor

Q How do you know the Xcelplus 2-stroke Treatment is working?
The RPM's increase

Q Is the Combustion Chamber Treatment any good for turbo chargers?
A Yes. Turbo chargers love the extra lubrication provided by the Xcelplus Combustion Chamber Treatment

Q Why does the Xcelplus Combustion Chamber Treatment work so well in turbo chargers?
A Xcelplus treats the metal with a super boundary lubricant that resists high temperatures and corrosion:

Turbo chargers fail because the exhaust gases that drive a turbo are a poor lubricant: The turbo charger environment is one of the harshest in the engine with speeds of up to 180,000 RPM and  exhaust temperatures of up to 1050 ºC

Q How do you ensure the Xcelplus Combustion Chamber Treatment (CCT) mixes well with the fuel in the tank?
A Wash down the CCT with a little bit of fuel or mix it in with some petrol prior to adding it.

Q Should you apply the Xcelplus Combustion Chamber Treatment (CCT) at the same time as the Engine Treatment?
A No. Stagger your application to avoid mobilising deposits all at once, especially in dirty engines. Apply the CCT a few weeks or a few thousand kilometres later.

Q Does it matter when you add the Xcelplus Combustion Chamber Treatment (CCT)?
A Yes. Add CCT after any engine cleaning is completed and after the Engine Treatment.

Q Will Xcelplus CCT protect leaded engines running unleaded fuel against exhaust valve recession and provide extra lubrication?
A Yes. The CCT will coat all surfaces exposed to combustion gases.

Q How can you tell that valve wear is reduced after treating with Xcelplus CCT?
A The need for valve adjustment is reduced

Q Will the Xcelplus 2-Stroke treatment stop power valves from sticking?
A Yes.

Q Will Xcelplus 2-Stroke prevent exhaust pipes from clogging up?
A Yes. A cleaner running engine will reduce or eliminate deposits in the exhaust pipe.

Q What is the most unexpected result of treating the combustion chamber in a 4-stroke engine?
A Pinging (pre-ignition) in single cylinder air cooled motorcycles decreased or disappeared.


Light Lubricant

Q How is the lubricant best applied?
A You can use a spray nozzle, a brush, a stick or a dropper: Only a small amount is required for most applications.

Q How long does the lubricant last?
A It depends on the application. It has a residual effect and lasts a long time. However it does not use the pfl technology (which lasts even longer) N.B. Try to avoid hot places and leaving the lid off to minimise evaporation of the light solvent carrier.

Q Where is the lubricant most effective?
A Anywhere a small metal surface has a friction problem

Q Does the lubricant work on heavy metal surfaces or surfaces with large loads?
A If you have very large heavy surfaces or surfaces with large loads the Xcelplus grease is a better choice.

Q Where do "you" find the lubricant works best?
A Locks and hinges. Especially locks made from cheap porous metals... which normally need repeated lubrication to keep working. It has an amazing penetrating ability and once in it lubricates and keeps working for very long periods of time.

Q What is the most unusual application you have found for the lubricant?
A The solenoids, pushrods, plunger and other moving parts on a pinball machine were sticking and required regular lubrication. One treatment with a very small amount of the lubricant solved all the sticking problems and lasted over 2 years.

Q Is it true that the Light Lubricant has a lower coefficient of friction than PTFE?
A Yes. The Coefficient of Friction (CoF) was tested as 44% (0.0223) lower than PTFE (0.04).



Q What base is used in the Xcelplus Grease?
A The Xcelplus Grease is petroleum based

Q What happens when you treat parts like bearings with the Xcelplus grease?
The parts last longer and require greasing less often (saves lots of work): This also means less grease is required.

Q How can I tell the Xcelplus grease is working?
A Usually it is possible to notice a decrease in rolling resistance after a short run-in e.g. Try rolling down a hill after you grease all the wheel bearings.

Q What temperatures does the grease resist?
A -29 - 260 ºC

Q Can the grease be used for marine applications?
A Yes. The grease resists being washed out and the permanent coating remains even after the grease is gone. 


Aircraft Treatment

Q How does the Aircraft Treatment differ from the other treatments
It is not as concentrated (to optimise treatment)

Q What kinds of aircraft engines does it treat?
A Piston engines up to 736 kW (1,000 HP)

Q Is it FAA accepted?
A Yes

Q How much is added to the aircraft engine oil?
A Use a ratio of 1:5 (17 %)

Q How often should you re-treat?
A Every 300 hours: to ensure optimum protection and performance

Q Can the Engine Treatment be used instead of the Aircraft Treatment?
A No. The Aircraft Treatment is FAA accepted and specially optimised (more dilute) to work better in aircraft

Q Is it cheaper to buy the Aircraft Treatment than the Engine Treatment?
A No. The bottle might be bigger but the Engine Treatment is more concentrated


Sludge Out

Q What is Sludge Out used for?
A For cleaning dirty engines e.g. Diesels often build up large deposits of carbon.

Q How long is Sludge Out left in the engine?
A 25-40 km: It is applied just before doing an oil change

Q Is there anything else we can do before treating with Xcelplus Engine Treatment?
A Add Ring Free for one oil change before treating with Xcelplus Engine Treatment.


Ring Free

Q What is Ring Free used for?
A To improve the performance of crankcase oils, to clean the engine and free up the rings

Q What kind of engines benefit from Ring Free the most?
A Very dirty engines will benefit from the extra cleaning e.g. Diesel engines with large deposits of carbon.

Q When should Ring Free be applied?
A After cleaning the Engine with Sludge Out.
One oil change before treating with Xcelplus Engine Treatment.

Q If the Xcelplus Engine Treatment has already been applied is it worth adding Ring Free?
A Yes. Dirty The performance of crankcase oils is improved and further sludge/carbon will be removed.

Q Is Ring Free a metal treatment like the Xcelplus Engine Treatment?
A No. It is an oil treatment. Oil treatments are flushed out when you change the oil


N.B. If you have an unusual application and you're not sure please ask us.