Lubricating Oil Matters



NOTE:  This is a short presentation outlining some of the basics of equipment lubrication.  It is intended to assist our customers in maintaining their equipment, both new and old.   It is NOT intended to replace or pre-empt any manufacturers or refiners recommendation(s).  Some of the opinions expressed are my own, based on my experiences over the years.  With that said, remember to always follow the manufacturer’s instructions provided in the Owner’s Manual.


Much has been written regarding motor oils and there has been many changes and improvements to lubricating oil, even in the past few years.  It can involve very complex chemistry and processes.

Here is some information regarding motor oil standards:

THE AMERICAN PETROLEUM INSTITUTE (API):  Since 1924, the American Petroleum Institute (API) has been establishing industry standards for petroleum products, including Motor Oils.  Grab a quart of motor oil and look at the label on the back – you will see the API Service Classification.  You will see letters such as “SE, SJ, SL” or “CD, CE, CJ-4,” etc..   These are the API Service Classifications that manufacturers will recommend for use in their engines.  

To break it down a bit, the first letter in the classification defines the type of engine – “S” for spark-ignition engines: Gasoline fueled or gaseous-fueled engines such as propane or natural gas.  “C” is for compression-ignition engines such as diesels. 

Why do we have all these different oils, you ask?  When a reciprocating engine is operated, a given fuel is burned and a certain amount of the by-products of combustion (gasses, soot, water) end up in the crankcase oil.  Many of these by-products are detrimental to the precision parts that make up an engine, plus there are many different metals used that need protection as well.  Also, engines can be operated in radically different climates which require different types of oils and additive packages.

An example: all diesel fuels contain a certain amount of sulphur.  When burned in a diesel engine, some of the sulphur will find its way into the crankcase oil as part of the aforementioned by-products of combustion.  The sulphur can mix with the water moisture in the crankcase which creates a type of sulphuric acid, which can attack and corrode the metals inside the engine.  Motor oils that are approved for diesels have additive packages that will help to neutralize these acids.

Depending on the fuel that is burned, engine manufacturers will specify different oils with different additive packages that will perform well and protect the internal engine parts when the equipment is operated in a certain temperature range.

Now, back to the API Service Classification.  The first letter designates the engine (fuel) type.   The second letter indicates the standard.  The higher the letter, the more recent the technology of the oil.

Here’s a history chart of the API “S” series spark-ignition (gasoline) specifications, as well as the newer ILSAC and GM’s Dexo's Specs     

Website Pic                                                                                                                                                                                       

Courtesy PQIA 2018

As you can see, the SA thru SE specs are now considered obsolete and SN oils are most current.  As explained earlier, the higher the letter, the more recent (and higher) the specification, which would supersede the lower specifications.  For example, if you had a car from 1990 that required an SG rated oil, any current specification oil – SJ, SL, SM, SN would be OK to use.

Diesel Lubricating Oils have different specifications.  Note that the CA thru CG-4 oils are considered obsolete and the CH-4 thru CK-4 oils are current specs.

 HDEO Timeline Picture For Web                                                                                                                                                                                                                 Courtesy PQIA 2018

As with the “S” series specifications, the higher the letter, the more recent the standard.  And it is backward compatible as well.  Just pay attention to the number after the letter, which indicates if it is recommended for 2 or 4 cycle diesel engines.

There are other lubricating oil standards organizations beside the API.  Here are several that we see in the US:

SAE:   The Society of Automotive Engineers, organized in 1905, is an international standards organization for the Automotive, Agricultural and Aerospace industries, among others.  The SAE standards for lubricating oil viscosity are in current use in the US and elsewhere.

ILSAC:   The International Lubricant Standardization and Approval Committee that works with the API regarding updated oil standards, primarily for the automotive industry.

JASO: The Japanese Automotive Standards Organization sets standards for lubricating oils for engines of Japanese origin.  Their standards are widely used for motorcycle and small engine lubricants.

PQIA:  The Petroleum Quality Institute of America is an independent resource for information and insights on the quality and integrity of lubricants in the marketplace.   Their website is a great resource regarding lubricating oils and independent product testing.


As previously mentioned, engine oils have different additive packages.   One is called ZDDP (Zinc dialkyl dithiophosphate), a silicate based lubricating compound developed in the 1940s that was first used in airplane engines. It wasn't long before petroleum companies added it to their motor oils to inhibit wear in automotive engines. Along with Moly (molybdenum disulfide), it was considered one of the most effective metal-on-metal anti-wear additives available.

Unfortunately, there has been a push from auto manufacturers to eliminate zinc from car motor oils, as high levels of ZDDP in a car’s crankcase oil can be harmful to the catalytic converter, especially if the car burns oil.   Since about 1990, most modern car engines utilize roller-tappet camshafts and lower valve spring pressures, so the need for anti-wear additives such as ZDDP is reduced.

The problem is with older engines equipped with flat-tappet camshafts.  They need extra anti-wear protection especially at break-in due to the high metal to metal contact inherent with this design.  Since most older automobile, industrial and tractor engines, as well as air-cooled engines do not have catalytic converters, using ZDDP in the engine oil is not a problem.  So, which oil should you use in these engines?  

When selecting motor oil for an older gasoline engine that may have a flat-tappet camshaft, take a look at the back label on the container.  If it has an API rating of “S” and has a symbol similar to this with the words “Energy Conserving” or “Resource Conserving”, chances are it has reduced levels of ZDDP.

For older gasoline engines with flat tappet camshafts and no catalytic converter, I look for a motor oil rated for both diesels and gasoline engines - CJ-4 / SN.  Because many modern diesels still use flat-tappet camshafts, diesel rated motor oils have higher levels of anti-wear additives such as ZDDP.  The SN designation indicates it is also approved for gasoline engine service.  An alternative is ZDDP oil additives.  In high performance (muscle car) engines, I have used an additive called ZDDPlus with good success.  Experts say that zinc levels should be maintained at around 1200-1400 PPM (0.12% – 0.14%) for these engines, especially for new engine break in.  However, they also state that too much ZDDP (levels approaching 2000 ppm or 0.2%) can actually be harmful to camshafts.


Personally, I use non-detergent oil only in applications such as reciprocating air compressors.  

All my antique car, tractor and equipment engines get CJ-4 / SM rated oils, regardless of age or hours on them.  For years I have heard that you should not switch to a detergent oil if the engine had been run for any length of time on non-detergent oil.  My experience has been to the contrary and my contention is that the detergents in modern oils are not aggressive enough to loosen enough old deposits to plug the oil pump or pickup screen.  The detergents are designed to keep the contaminants in suspension and will be picked up by the oil filter as they pass through.


Today’s trend toward synthetic lubricants and synthetic blends is well founded.  Synthetics have been around for a long time and have been proven to provide superior performance in many applications.  Higher product cost has always been a factor, but when labor costs and extended drain intervals are considered, synthetics are now a viable alternative.


We all have seen (and have been tempted by) the low price of “303” Tractor Hydraulic Fluid in the 5 gallon pails.  They usually have a long list of approved manufacturer’s specifications on the back panel which makes us think we are buying a product that is “approved” for our tractors.   

Here’s a few interesting facts regarding “303” tractor hydraulic fluid:

  • There is no current “303” specification.  John Deere created the J303 spec in 1960 and it was replaced by the J14B spec in 1974, which was 44 years ago!  
  • Since there is no specification, any products making “303” claims cannot be evaluated.  If there is no standard to meet, there is no assurance of quality or ingredients.
  • The states of Missouri, North Carolina and Georgia have recently issued Stop Sale orders on  the “303” labeled tractor hydraulic fluids.  Missouri, North Carolina and Georgia have banned the sale of “303” specification hydraulic oils as they found these products were mislabeled and failed to meet any current specification.  Missouri has also found other mislabeled and substandard motor oils, anti-freeze and ATF products.  
  • Many of the other specifications listed on the “303” oils are also obsolete.  If you look closely, many of the manufacturer’s specifications on the label are not current and are actually obsolete.
  • Check the label!  Be sure the oil Tractor Hydraulic Fluid you are buying meets the current manufacturer’s specification of your equipment.  With AGCO/Massey, it is Permatran 821XL Semi-Synthetic.  With John Deere, it is the J20C spec. 

Here’s a timeline showing the history of Deere’s Tractor Hydraulic Fluid specifications, including their J303 specification:


Courtesy PQIA 2017

The lesson here is to always buy quality.  Studies have shown that lubrication and maintenance typically accounts for less than 5% of total cost of ownership, so skimping on maintenance doesn’t save much.  As with any purchase, I always buy the best that I can afford.  My uncle used to say “Grease and oil is cheaper than parts”.     And a wise man he was.


NOTE:   Always refer and follow the manufacturer’s Owner’s Manual!  

Manufacturers conduct much research regarding lubricants and maintenance and know what works best their products.  

So, the skinny is:  Read the manual and follow it.  Buy quality fuel, oil and filters and don’t skimp.  Take care of your equipment and it will serve you well.

Here’s what we use: 

Massey-Ferguson and Mahindra Compact Tractors:

ENGINE:  AGCO MultiGuard SAE 10W-30  (CJ-4, SM) – (year round)

                 ALTERNATE: AGCO MultiGuard SAE 15W-40 (heavy duty service-hot weather)


FRONT AXLE:  AGCO Permatran 821XL Semi Synthetic

Hustler Mowers:

ENGINE:  Kawasaki K-tech SAE 10W-40 Synthetic Blend w/Zinc

                 ALTERNATE:  AGCO MultiGuard SAE 30 (warm weather only)

TRANSMISSION:  Hustler Full Synthetic Hydrostatic Transmission Oil 20W-50 

                              ALTERNATE:  Mobil 1 Full Synthetic SAE 15W-50

Ariens Snowblowers:

ENGINE:  AGCO MultiGuard SAE 5W-30    (for units stored inside)

                 ALTERNATE: AGCO MultiGuard SAE 5W-30 (for units stored outside)

Winco Standby Generators:

ENGINE:  We recommend using Mobil 1 Full Synthetic 5W-30 after engine break-in.

Honda/Briggs/Kawasaki/Kohler/LCT Air- cooled engines:

ENGINE – (Summer use):  We recommend using the Kawasaki K-tech SAE 10W-40 Synthetic Blend w/Zinc.     ALTERNATE: AGCO MultiGuard SAE 30 or AGCO MultiGuard 10W-30 

ENGINE – (Winter use):  We recommend using AGCO MultiGuard SAE 5W-30 or 10W-30 motor oil.

Disclaimer:   The above information was compiled from several resources and also includes information resulting from my personal experience in this business.  It also includes my personal commentary and opinion.  It in no way pre-empts or supersedes any manufacturer’s recommendations or requirements.  Remember to always follow the manufacturer’s recommendations regarding the operation and maintenance of your equipment!

All rights reserved.  This information is intended for exclusive use by the employees and customers of Goff’s Equipment Service, Inc..   Any reproduction or distribution of this presentation must be authorized in writing by the General Manager of Goff’s Equipment Service, Inc., a Connecticut corporation. 


The American Petroleum Institute

The Society of Automotive Engineers

The Petroleum Quality Institute of America

Deere & Company

AGCO Corporation