Converting to AMSOIL

If you want to buy AMSOIL Products, visit the AMSOIL On-Line Store or download a clickable pdf e-catalog

Converting to AMSOIL or Breaking in a New Engine: Critical Information That You Need to Know.


Some of the most frequent questions people ask us about AMSOIL are:  what is required in order to convert to AMSOIL synthetic oils and filters, how long do I have to wait before installing AMSOIL in a new engine, what about motorcycles, and what differences can I expect to notice once I’ve converted to AMSOIL?


Here are our former-OEM-engineer’s answers in a detailed explanation: 

Converting a vehicle to AMSOIL synthetic oils and filtration is fairly simple, but there are a few things you need to be aware of.  If you follow these recommendations, which go beyond what your owners manual or the dealer mechanic tells you, your new engine will probably last 3 to 5 times longer than the OEM plans.  With a used engine you’ll probably triple the remaining life.

(Yes, we’re serious.  That’s not marketing talk. It’s the engineering consensus of
our entire group of hundreds of automotive and OEM engineers, based on the three greatest secrets of vehicle maintenance and real-world experience and data, like the Million Mile Van that wasn’t converted to synthetics until 68,000 miles.)

Having said that, we’ll also tell you this priceless secret:  a similar situation holds true for your transmission and differential.  By changing the fluids to AMSOIL synthetics after about 1,000 to 5,000 miles of “babying” them for a good break-in, and then changing them at the 50,000 mile severe service intervals, or 100,000 mile normal/typical service intervals, most transmissions and differentials will run at least 400,000 and probably more than 1 million miles without problems.  The exceptions are mostly vehicles with engine horsepower upgrades, vehicles competing in events or special applications such as off-roading, and those being used to tow or carry loads well beyond their designed and rated OEM capacity.

[Additional valuable information is available free such as
how to make your new vehicle last 500,000 to 1 Million miles,
including the transmission and differential, and
our FREE expose’ on the three biggest automotive secrets.]

Engine “Break-In” Period:

If you have a brand new vehicle we recommend that you run a short cycle of petroleum oil on a gas engine passenger car or light truck (typically 500 miles) and approximately 5000 miles on a diesel engine such as in a Ford Powerstroke, GMC Duramax or Dodge Cummins Turbo Diesels, before installing AMSOIL. This doesn’t mean that you can’t install AMSOIL sooner, as many OEM’s install synthetics as a factory fill in performance vehicles. It simply means these are our recommendations based on our extensive engineering studies and knowledge of this topic. Your engine’s oil usage rate can be higher until the initial break-in process is complete.

Today’s engine manufacturing and materials technology is much more sophisticated than in past decades. Regular gas engine passenger car and light truck engines do not require the extensive break-in process many people think they do. In addition, by the time you get your new vehicle the engine has already been through a series of hot tests also run on in-plant chassis roll testers to check functionality of all systems and then driven around the plant and railhead in order to get the vehicle to the dealer, which also helps accelerate breaking in of the engine.

The engine break-in issue is the subject of much controversy as everyone seems to have their opinion on when an engine is considered fully broken in. The information we provide is based on the results of engineering studies as well as many years of experience and teardown analysis on test vehicles. The differences between a vehicle that was properly and fully broken in, and one that was not, can often be hard to detect.  There are tell-tale signs, but they are not easily detected except in all but the most extreme situations. The subject of what occurs during the break-in process can easily be the subject of a 100 page report, so what we cover in this website page is only the essential points you need to know. The break-in process we describe here is nothing compared to the extensive break-in process that race car engineers go through before an engine is ready to be converted to AMSOIL as well as racing in competition.

Breaking in an engine is a process of properly wearing-in the pistons/cylinders/rings, bearings, valves, camshaft, lifters, rockers, etc… In addition, part of the breaking in process is not only wearing-in and seating the internal engine components but also stress relieving the components as well. Crankshafts, connecting rods, pistons, blocks etc… have many stresses due to the casting or forging process, machining and welding process. We have viewed and measured these stresses, called fringes, using what is called laser holography. These stresses are properly reduced/eliminated by costly and time consuming heat aging as well as shot peening and or high frequency vibration on a very specialized bedplate for an extended period of time. For production applications this is cost and time prohibitive. Therefore, the next best thing is exposing your engine to multiple heating and cooling cycles under various load and RPM’s, which is described in the following paragraph. The heating and cooling break-in process continues over a period of time and does not need to be run on petroleum oil.

Breaking in a new engine is the one area that petroleum oil is better for than synthetics. You see, petroleum oil has a very low film strength compared to synthetics – about 1/7th to 1/10th.  That’s bad for long-term wear-protection, but it’s ideal for breaking in a new engine. That is why we recommend you run the factory installed petroleum oil for about the about the first 500 miles. Then drain the oil, remove the factory installed oil filter and then install AMSOIL Synthetic motor oil and an AMSOIL EaO oil filter and you’re ready to go.  For diesel engines we recommend the same procedure, except at the 500 mile oil-change use conventional petroleum oil combined with an AMSOIL EaO nanofiber oil filter. The petroleum oil will better allow the break-in to continue, while the nanofiber oil filter will reduce wear particle damage by about 70% compared to standard or OEM filters.

Further heat cycling break-in will continue during the multiple heating and cooling cycles from driving your vehicle under varying RPM and engine load conditions and then shutting it down for a long period of time to let it cool completely. The multiple heating and cooling cycles are a extremely important factor in properly breaking in a new engine and are often an overlooked factor in the total break-in process. These heating and cooling cycles achieve what is called stress relieving. Back in the “old days” of engine manufacturing, after casting and before an engine block was machined, it would be set outside for several months to age, during which stress relieving occurred naturally, then the block was machined, which helped to produce a better engine than one that was machined immediately after casting.

By changing the factory installed oil and filter after the first 500 miles you will also be removing the initial wear-in particulates present in the oil and filter. The reason for this is that during initial wear-in there is very high particulate contamination in the oil. These particulates consist mainly of microscopic particles of aluminum, bronze, copper, lead and iron, plus soot particles and other by-products of combustion in your oil. Your filter cannot filter out all these small particulates as many are sub-micron size and too small for the filter to trap, BUT they are also small enough to fit between your bearing and other internal clearances and cause wear. That is why we recommend to you that in order to properly break-in a new engine, regardless of what your new car salesman or dealership personnel tell you, you should always perform the first oil and filter change at 500 miles. Then you can convert to an AMSOIL Synthetic at that time, or any time later.

On a diesel engine we recommend the initial oil change at 500 miles with a petroleum oil and an AMSOIL EaO or Donaldson Endurance oil filter, and  another petroleum oil change around 3,500 miles.  Then in the 5,000-10,000 mile range you can convert your diesel engine to AMSOIL Synthetic.

How do I Convert to AMSOIL?

Use AMSOIL Engine and Transmission Flush:  In a new engine with less than approximately 20,000 miles it is not imperative that AMSOIL Engine Flush be used.  However, in an engine that has AMSOIL Engine Flushbeen using petroleum oil the entire time with 20,000-30,000 miles or beyond, or more than 2 years old, we highly recommend using the AMSOIL Engine Flush. The flush procedure will remove the petroleum oil sludge & varnish deposits from your engine, along with the wear-particles embedded in those deposits, and properly prepare your engine for AMSOIL Synthetic Motor Oil.

Here’s the AMSOIL conversion procedure:

You simply pour in one bottle of AMSOIL Engine Flush for every 4-6 quarts of sump capacity (one can is sufficient for most all passenger cars & light trucks, with the exception of diesels), and let the engine idle for about 15-20 minutes then drain the oil and remove the filter while the oil is still warm. Do not drive the vehicle or put any load on the engine with the engine flush installed, or some internal engine-wear-damage may occur due to the thin viscosity. The best practice is to install a new (sacrificial) oil filter before adding the engine flush. However, in some cases this is probably not critical – such as only having 3,000 miles since the last oil change, and you’ve been running Mobil 1 for most oil changes.

But if you have a high mileage engine or suspect it may have heavy petroleum buildups, or  if your engine is prone to sludge buildup, or you have recently purchased it as a used vehicle, then we definitely recommend installing a new engine oil filter prior to adding the flush so that you have full capacity of the filter available for capturing and holding the dirt particles that the flush removes. What’s the difference between AMSOIL Engine Flush and other products you might find in an auto-parts store?  AMSOIL’s Engine Flush is designed for maximum performance, rather than maximum profits.  It’s a detergent-based flush with some kerosene and other petroleum distillates that act as the carrier for the flushing and cleaning agents. The detergents are essentially a very concentrated form of the detergents used in premium motor oils.

                     (What about using Engine Flush in my Motorcycle?)

AMSOIL Synthetics are naturally cleansing and also high in detergents. What happens when you operate an engine on petroleum oil, is that the sludge and varnish deposits that occur as a result of using petroleum oil will accumulate around your pistons, rings, seals, valvetrain, etc.. and actually help to seal your engine. This type of petroleum oil deposit “sealing” can lead to problems such as piston ring sticking, sludge deposits in valve covers and oil pans which can lead to decreased oil pump capacity output and restriction of critical oil galley passageways over an extended period of time, plus many more issues which we will not go into detail in this discussion. These deposits are highly detrimental to the proper function and longevity of your engine.

What occurs when you use AMSOIL Engine Flush is that it cleans all these deposits out from your engine, both the highly accumulated deposits as well as the sub-micron deposits which have accumulated in the microscopic valleys of the aluminum, copper, iron, etc.. engine components. If you do not use the engine flush the AMSOIL Synthetic Motor Oil will do essentially the same thing the flush does, but take a much longer period of time. During this time, which is greatly accelerated when using the AMSOIL Engine Flush, the engine is going through a phase where these deposits are being removed, or have been removed. What exists now is that these microscopic valleys in the iron, aluminum, copper, etc.., are now empty. It takes some time for the molecular structure of the AMSOIL Synthetic Motor Oil to fill these microscopic valleys. This can be as short as a few hundred miles or as long as a few thousand miles, depending on the internal condition of your engine. During this phase you may, or may not, notice slightly increased oil consumption, BUT only until the uniform molecular structure of the AMSOIL Synthetic Motor Oil can re-seal these microscopic valleys. Most people do not even notice this phase, but we like to make people aware of it so they understand this process. This is perfectly normal and the oil is doing exactly what it was engineered to do.

Gaskets and Seals:

You may have heard the myth that synthetics cause engine seals to leak. Synthetics absolutely do not cause seals to leak, by they may clearly reveal an existing leak path and seal which has failed and is in need of mechanical replacement. Either the seal lip is worn down or the seal is hardened and cracked from old age, heat and ozone. What happens is exactly as we described above. If you have a very old engine that has been running petroleum oil, and it also leaks, for example around the rear-main oil seal, then chances are it will leak more with synthetic oil. This is commonly referred to as a “false seal”.

Q: “I’m concerned.  Can you explain more about Cracked or Leaking Seals?”
A:  There is some risk on older engines with high mileage on petroleum oils, that the oil seals are cracked from being extremely dried out, and are being sealed with sludge deposits.  Some feel that because this low risk exists, that they should not switch to AMSOIL because the cracked seals will begin to leak.  However, it is these deposits which are often the primary cause of seal wear and cracking, because they prevent the oil from cooling the seal and prevent the oil’s seal conditioners from keeping the seal soft and lubricated.  Our opinion, as automotive engineers, is that when this condition exists it often indicates a high level of sludge and varnish deposits in the engine which are decreasing engine life and as they continue to build up they are creating an ever-higher risk of rapid or sudden engine failure.  It’s similar to the risk of cholesterol deposits closing off your arteries and causing heart attacks under stress conditions.  So if cracked seals leak badly after switching to AMSOIL, and you have to replace them, it’s probably an indication that you’ve dramatically extended your engine life by switching to AMSOIL.  And that’s great!  No-one wants the expense of replacing seals, but it’s much cheaper to replace the seals than to replace the engine!

Synthetics cause gasket failure?  Recently I heard of a respected ASE-certified mechanic recommending to one of my brothers that he should not change his Cadillac over to synthetic because there was visible indication of very slight “seepage” at a gasket, and that if he installed a synthetic it could cause gaskets to fail – “and a head gasket failure is an expensive repair”.  I shared this with an automotive engineer at GM headquarters, who makes Cadillacs.  He responded with a tone that nearly dripped with derision: “What does using a synthetic have to do with a head gasket failure!?!  I’d like to hear the logic behind that one!”

Again, AMSOIL synthetics are rigorously designed to be even MORE compatible and beneficial to gasket and seal materials than conventional oils.

Similar wild stories are widespread, shared by “experts” who may or may not be well-intentioned.  Typically the anti-synthetic stories seem to be rooted in either the petroleum oil companies anti-synthetic propaganda years ago (before introducing their own “synthetic”), or from a well-intentioned mechanic who mis-diagnosed the cause of a customer vehicle’s problem.  (I personally know one of these mechanics.  He’s respected in his tiny country-town community, but he has no interest in logically discussing obvious weaknesses in his conclusions.)

But a weak gasket is a weak gasket.  It was probably either weak from a manufacturing flaw, or was damaged slightly during the original engine assembly or from overpressure caused by engine modifications.  And it might fail at any time.  But just because it occurs a few days/months after changing oil brands does not mean that the oil had anything to do with it.  That’s called “pure coincidence”.

Q: What about my leaking main seal?

A:  If it is “seeping” slightly, that typically means that it’s got deposits on the other side that are keeping the seal-conditioners in the oil from getting to it, and so it’s drying out and shrinking.

I had that problem – a classic one – on my ’94 Taurus SHO (Super High Output). Except it was leaking enough to keep the bottom of the engine and transmission wet with oil, and MAYBE occasionally put a single drip on the pavement, with 60,000 miles on it. Now, “everyone” in the national SHO Registry owner’s club seemed to “know” that you MUST replace that leaking Yamaha seal, including the top American mechanics who are recognized SHO experts. But I didn’t change the seal. I just changed to AMSOIL. And in the first couple thousand miles, it leaked more. (Right on par, as expected, due to cleaning the deposits out from around the other side of the seal.) Then over about 5,000 miles that oil leak got smaller and smaller. After 10,000 miles you could barely tell there was a leak. (Typical results of AMSOIL’s superior seal-conditioning packages.) By the time my SHO had 80,000 miles on it, the underside looked like there might have been an oil leak sometime, or maybe one starting, but you sure couldn’t tell where. The rear main seal leak was gone – cured by AMSOIL.

REALITY CHECK – Summary on Seal and Gasket Compatibility:

AMSOIL synthetic motor oils are made of completely pure, ideally designed synthetic base-stocks, blended with the highest-performance additives available, and are fully compatible with all engine gaskets and seal materials.  In fact, because they are more painstakingly designed than petroleum oils, they help maintain seal integrity better, and AMSOIL extends seal life better than conventional oils.  However, AMSOIL Synthetic Motor Oils are recommended for use in mechanically sound engines!  If you have a vehicle that is actually leaking oil badly, then it may be best to repair the seal prior to converting to AMSOIL.  And it’s a smart move to replace those seals and switch to AMSOIL – seal problems often indicate high levels of internal engine deposits, and replacing the seals is a lot cheaper than replacing the engine.

Motorcycle transmission clutch and shifting with engine flush

Special note to motorcycle owners considering AMSOIL:

Petroleum deposits are the PRIMARY cause of shifting problems and clutch slippage in motorcycles.  However, we do not recommend the use of Engine Flush in motorcycle transmissions or “common-sump” designs that use the engine oil in the “wet clutch”.  Since AMSOIL motorcycle oils are specially formulated to remove these deposits, they will automatically be dissolved from synchronizers and clutch-pack friction surfaces over the first few thousand miles.

This is another reason the motorcycle market is quickly gaining momentum in changing over to AMSOIL lubricants: not only because of increased horsepower, superior corrosion protection and far lower wear rates, but because riders typically report smoother running engines and transmission shifting that gets better and better over about the first 2,000 to 4,000 miles.

Obviously AMSOIL lubricants can do nothing to fix mechanical damage.  However, we regularly hear many stories of riders with low-mileage bikes who are afraid that they need a transmission or clutch rebuild, who then switch to AMSOIL and have their shifting problems quickly disappear.

(A Chevron lube specialist praises AMSOIL motorcycle oil?)

^Return to Flush Procedure Above

AMSOIL Benefits –
Once you have installed AMSOIL you will have the following benefits:

Easier cold weather starting, improved cold weather pumpability and circulation, smoother engine performance and more horsepower, reduced exhaust emissions, superior wear protection, improved fuel economy, extended engine life, extended starter life, excellent engine cleanliness, long drain intervals, longer spark plug life, reduced engine temperatures, reduced oil consumption, excellent resistance to sludge, coke, varnish deposits (Thermal Stability), reduced/eliminated piston groove sticking, reduced/eliminated valve sticking, superior shear stability, superior resistance to viscosity increase (Volatility Resistance), superior film strength, no more stuck oil filters (using AMSOIL EaO filters), money and time savings.

You will not get any of these benefits with conventional petroleum oil !!!!!

When you compare….

there is simply no comparison to AMSOIL synthetic oils.