After 70+ years of trouble-free, metal-metal engine
protection, the E.P.A. is forcing ZDDP (Zinc Dialkyl Dithio
Phosphate, containing both Zinc and Phosphorus) from domestic motor oil. If your
engine was designed prior to the 1990s, your non-roller lifters
require ZDDP in your motor oil to avoid premature deterioration.
Don’t let your lifters run metal-to-metal. Keep ZDDP, via ZDDPlus™,
in your motor oil.
Add 4 oz of
ZDDPlus™ at every 4 to 5 quart oil change.
ZDDPlus™ is a product offered by
car enthusiasts
to meet the needs of classic car
aficionados.
The automotive industry in general
is changing in response to the environmental and
financial pressures of today, with little concern for
the classic car industry. We are engineers and
automotive technicians by trade, and bring many years of
problem solving experience to the task of keeping our
classic cars operational and running better than new. We
hope that one of the solutions we have designed for our
own use will meet your needs as well. We have developed
ZDDPlus™
to address
the needs of classic car owners for an oil that will
meet the specifications of the original oil for which
their engines were designed.
Why do we need
ZDDPlus™
?
As part of
an effort to reduce vehicle emissions, the U.S. EPA
offers vehicle manufacturers "credits" for early
implementation as well as penalties for violation of
emission reduction standards. The EPA's program called
for 100,000-mile catalytic converter life by 2004,
120,000 miles by 2007, and 150,000 miles by 2009. To
achieve these goals, automotive manufacturers have
pressured their oil suppliers to remove substances from
motor oils that would shorten the service life,
including the proven EP (extreme pressure) additive ZDDP
(zinc dialkyldithiophosphate). Zinc and phosphorus from
the ZDDP can be present in small amounts in the exhaust
gas of an engine depending on the amount of oil which is
consumed in combustion. These elements can coat the
catalyst reducing the amount of catalyst exposed to the
exhaust gases, ultimately increasing emissions at the
tailpipe. As a result of the EPA mandate, the ZDDP level
in engine oils has been declining since the mid-1990s,
roughly coinciding with the implementation of OBDII.
ZDDP has been an
important additive to engine oils for over 70 years, and
has an excellent track record at protecting the sliding
metal-to-metal cam lifter interface. Historically, ZDDP
has been added to oils in amounts resulting in
approximately 0.15% phosphorus, and 0.18% zinc. ZDDP
protects by creating a film on cams and flat lifter
contact points in response to the extreme pressure and
heat at the contact point. The film of zinc and
phosphorus compounds provides a sacrificial wear surface
protecting the base metal of the cam and lifter from
wear. In the course of normal service, this conversion
of ZDDP to zinc and phosphorus compounds depletes the
ZDDP level in the oil. Studies show that depending on
the specific engine and severity of duty, after
2000-4000 miles of operation, the level of ZDDP can drop
below that considered adequate to provide wear
protection to the cam and lifters.
According to
the SAE Tech Bulletin # 770087
[1]
, operation of a flat tappet engine
without adequate EP additives such as ZDDP quickly leads
to lifter foot scuffing and cam lobe wear. Camshafts are
typically only surface hardened leaving the core ductile
for strength. According to the SAE Bulletin, once cam
lobe wear reaches 0.0002, "subsequent wear is usually
rapid and catastrophic." Two ten-thousandths of an inch
is one fifth the thickness of an average human hair.
In
order to make engines last in the absence of ZDDP,
virtually all IC (internal combustion) engines designed
in the last ten years utilize roller lifters. Today,
ZDDP has been removed from practically all automotive
engine oils, rendering them unsuitable for use with
older engines with non-roller lifters.
Because
contemporary engines with roller bearings no longer
require the additional protection of Zinc and
Phosphorus. Not true for classic cars, tractors, muscle
cars, etc. Also removing the Zinc and Phosphorus from
motor oil increases the life of the catalytic converter.
But classic cars, tractors, etc., don’t have cats! Also,
as part of its ongoing effort to reduce vehicle
emissions, the EPA has mandated that emission systems
must have a service life exceeding 120,000 miles. To
achieve this, automotive manufacturers have required oil
suppliers to remove additive packages from motor oils
that could reduce emissions compliance.
ZDDPlus™
is the ONLY EP (Extreme
Pressure) component which re-establishes the ZDDP levels
that our classic car engines were designed for, while
allowing the car owner to use the base oil of their
choice. While some off-the-shelf additives may have some
ZDDP, the amount per bottle is small, and when enough is
used to get the proper concentration of ZDDP, there is a
quart or more of unspecified oil that comes along with
it. This dilution of 20% of your oil with an unspecified
oil also means that there is 20% less of the proper
additive package. The chart below compares the amount of
ZDDP in ZDDPlus™
to GM
EOS, an additive which claims to provide ZDDP based wear
protection.
[1]
Pless, Loren G., and Rodgers, John J., ‘Cam and Lifter
Wear as Affected by Engine Oil ZDP Concentration and
Type’, SAE pub 770087, 4 (1977)
As lubrication
technology improves, so does the base oil used in the
manufacture of engine oils. Oils are also changed and
updated in response to advancements in engine
technology.
Modern
engine oil is a precise mix of a base oil with additives
totaling almost 10% of the oil by volume. Pound for
pound these additives are each more expensive than the
base oil, and oil companies are in business to make a
profit. Common sense says that these additives are there
with Modern engine oil is a multi-purpose fluid in an engine,
carrying the heat away from hot spots and releasing it
in the sump as well as providing lubrication to critical
areas which need protection against wear. Different
additives are put in the oil in order to address the
needs of each specific engine system that is supplied
with oil:
The crankshaft and connecting rod bearings
discharge oil into the spinning reciprocating
assembly, and an anti-foaming additive keeps the
oil from turning into foam.
The heat developed on high-pressure contact
areas can exceed the breakdown temperature rating
of the base stock, so heat stabilizers are added
in order to fight viscosity breakdown and
ashing.
In a multi-viscosity oil, the
multi-viscosity characteristic is established by
an additive.
Acids and byproducts of combustion are
neutralized by another additive.
A
dispersant additive helps keep combustion
particulates from clumping.
Detergents are added to lower the surface
tension to a specific value to help keep
contaminants in suspension and off of the metal
engine parts. Some detergents also interact
with the EP additive to gain an additional level
of wear protection.
The sliding
cam-to-cam-follower interface in a non-roller
lifter engine requires a special EP additive,
which has historically been the ZDDP that is now
reduced in all API rated automotive
oils.
ZDDPlus™
contains the
proper amount of ZDDP to give at least 0.18% zinc and
0.13% phosphorus level when a single 4 oz. bottle is
added to a normal 5-quart oil change. This level of zinc
and phosphorus is the level designed into pre-OBDII
oils. Using
ZDDPlus™
affords you total control over the
characteristics of the oil in the engine by allowing you
to use the full 5 quarts of a high-grade automotive oil
of your choice.
F Read the
Tech Brief (Page
3) for
more information
What about off-the-shelf additives and supplements?
API oils have always been more than
adequate for the engines designed when the oil was current. The
use of current API grade oils has always been adequate to
satisfy car manufacturer's requirements and warranty demands.
Historically, with few exceptions, newer API grades have
superseded the performance of their predecessors.
The removal of ZDDP has resulted in a clear change to that philosophy. It has
never been necessary or desirable to include additives or
supplements to any API rated oil to meet car manufacturer's
specifications or warranty requirements. In virtually all cases,
off-the-shelf additives amount to little more than automotive
snake oil. Current additive technology has yet to develop an EP
anti-wear agent as effective as ZDDP. Consequently, if these
additives actually had adequate levels of ZDDP, they would be
incompatible with modern engines and void manufacturer's
warranties. Due to this unprecedented turn of events in
emissions requirements,
ZDDPlus™
should not be confused with an off-the-shelf additives.
ZDDPlus™
should be considered a replacement for a
missing oil component critical for older cars.
Current additive technology has yet to develop
an EP anti-wear agent as effective as ZDDP.
ZDDPlus™
is not a
typical oil additive. By adding a small 4 ounce bottle
of
ZDDPlus™
at every oil change, an
adequate amount of Zinc and Phosphorus will continue to
protect your classic engine.
ZDDPlus™
simply maintains the Zinc and Phosphorus that has recently been
removed.
Why Can't We Use Diesel
CI/CJ-4 Rated Oils?
There are
some diesel engine rated oils on the market which may
still have some ZDDP in them. There are problems
associated with using these oils in a normal gasoline
engine which can become severe in a high-performance
gasoline engine. One issue is the high amount of
detergent additive, and another is the high
viscosity.
High
detergent oil has a lower surface tension and lower
shear pressure rating which can cause higher bearing
wear in gas engines. A diesel engine needs oil with very
high detergent capabilities in order to hold the large
amount of combustion byproducts in suspension, but it is
not optimized for a gasoline engine. The bearing journal
size-to-displacement ratio on a gasoline engine is
designed around the use of a lower detergent oil and
relies on a high-shear rating to the
oil.
The other problem
with high detergent oil is that it actually reduces the
friction reduction that the ZDDP affords, especially in
a high-performance, high valve spring pressure
engine.
The viscosity
rating of most diesel rated oils is higher than optimum
for our higher revving gasoline engines, and can cause
oil starvation in bearings at high rpms.
F Read the
Tech Brief for
more information
There are some racing
oils which maintain a level of ZDDP. Racing oils are
optimized for short term severe duty, in contrast to an
oil that has been designed for day in, day out street
operation. The additive package in a racing oil does not
have the same detergent characteristics which are
designed into extended service oils. As a result, racing
oils may not have the capability of neutralizing acids
and keeping contaminants in suspension. Also, the
breadth of choice of viscosity, so important to correct
street engine operation over a broad temperature range,
is not available in racing
oils.
By using
ZDDPlus™
in addition to a modern
high-quality oil of the proper viscosity for your
gasoline engine, the correct EP lubrication level is
established, and the oil characteristics remain
optimized for your engine.r
engine.
ZDDPlus™
is an oil supplement that
contains very high concentrations of the well-known
additive ZDDP (Zinc Dialkyl Dithiophosphate), which has
been the primary EP (extreme pressure) ingredient in all
quality motor oils for over 70 years. However, beginning
in the late 1980s, the concentration has been greatly
reduced as newer oil classifications have come on the
market.
F Read the
Tech Brief for
more information
^ Top
Why do I need ZDDP?
The EPA
has put stricter emission requirements on new cars that
influenced manufacturers to remove ZDDP from motor oils.
If you have an older car that was specified to use SF
(1988) or earlier motor oil, its design requires ZDDP.
Your older performance car could be damaged with the use
of modern SM oils prevalent today. Cars equipped with
flat tappet cams need ZDDP because of the high-pressure
points. Newer cars have roller rockers and ZDDP is not
needed in those applications
^ Top
What do the oil grades such as "SF"
indicate
?
In the
API (American Petroleum Institute) classification
system, "S" and "C" are the two basic application
categories of oil. "S" is intended for gasoline use and
"C" is intended for diesel use.
"A" was the
first grade in each category and resulted in "SA" and
"CA" grade oils. Each designation progressed farther up
the alphabet as new grades of oil were introduced. The
newest grades are "SM" and "CJ" respectively. "SF" was
for 1988 and older engines.
Historically, every new grade of oil introduced since
the 1930's was better than the previous grade and could
be considered "improved" with one exception. The
original SA grade was straight mineral oil
(non-detergent non-additives) and SB contained additives
which could not be used in the earliest cars specified
for SA. While it is true that SM oils are better for NEW
cars, they are NOT better for the OLDER cars equipped
with flat tappet camshafts. Simply put, the newer,
better oils are not backward compatible for older cars
primarily due to the gradual reduction of ZDDP starting
with SG grade introduced in 1988. In the next few years,
it will be eliminated completely from
oil.
One bottle of
ZDDPlus™
will
raise the ZDDP concentration level of SL or SM oil to
the standards that were in place when SF (or earlier)
oil was specified. (SL and SM is the current category
available today).
ZDDP is most
effective if the concentration is between 0.18 and 0.2 %
by weight. Tests have shown that concentrations above
this amount, up to as much as several percent, have no
effect except to prolong additive life. The current oils
available today contain very little ZDDP.
Can I use
ZDDPlus™ with regular or
synthetic
oils?
Yes,
ZDDPlus™
should be compatible with all
conventional and synthetic oils intended for automotive
use. Virtually all of these current oils have had some
amounts of ZDDP for years, and it continues to be
decreased in available oils.
The
shelf life of
ZDDPlus™
is essentially the same as
regular motor oil (many years), as long as a few
conditions are met. The temperature should be kept below
120 degrees F and above 0 degrees. You need to keep it
sealed until it is mixed with motor oil.
ZDDPlus™
has a tendency to absorb
moisture, not unlike brake fluid. Absorption of water
will degrade its performance, although heating it above
100C until it is not cloudy will restore it.
Anytime, but the best time is when you get the oil
changed. A single 4-oz bottle is the correct
concentration for a 4- to 5-quart oil change. This will
bring the oil back to SF specifications.
ZDDPlus™
is a sacrificial additive,
meaning that in the process of working, it is depleted.
ZDDPlus™
should last the life of a
normal oil change as specified by the manufacturer of
the car, but attention should be given to the categories
of service known as "normal" and "severe" conditions.
Severe includes stop-and-go driving and short trips,
which result in shortened service life of not only
ZDDPlus™
, but most of the other additives in
the oil.
The general public, as a rule, has nothing to be
concerned about. The people that need to be concerned
are owners of older classic cars and performance cars.
After the SF category, the amount of ZDDP has gradually
been reduced as each new API category is introduced. Had
ZDDP been removed completely after 1988 (SF), the
scramble for an alternative would have been a big
concern. But, since it happened gradually, the concerns
were not so obvious.
The key ingredient of
ZDDPlus™
is ZDDP, which has been known
to shorten catalytic converter life. Manufacturers have
been redesigning engines for the last decade to minimize
the need for ZDDP, in order to lower emission levels.
One method is switching over to roller rockers.
Why not just use diesel
rated oils, since they contain higher levels of
ZDDP?
Diesel engine requirements are much different that those
of gasoline engines. The higher speeds and lower bearing
surface-to-power ratios of gasoline engines require oil
with higher shear ratings than most diesel oils. Diesels
also have higher bearing clearances and that calls for
higher viscosity oils. The additional detergents
required for soot control actually reduce the
effectiveness of added levels of ZDDP found in diesel
oils. Also, newer diesel oils beginning in 2007 have
greatly reduced their content of ZDDP.
Historically, EOS was the most concentrated ZDDP
supplement available. It was intended to boost ZDDP
levels of oils that already contained EP additives. EOS
was packaged in a 16 oz bottle. It also sold for over
$10 per bottle.
ZDDPlus™
is
packaged in a 4 oz bottle and contains TWICE the amount
of ZDDP contained in EOS, since it is intended to be
used with newer oils that contain little or no ZDDP. In
the summer of 2007, EOS was discontinued, making it
difficult to find today.
What about the
additives offered by the cam manufacturers?
Some
of the "Break-in" or "assembly lubes" offered by cam
manufacturers contain marginal amounts of ZDDP while
others offer virtually none. In most cases these
products are intended for initial run-in and rely
primarily on other additives such as
MDS (molybdenum
disulfide). These
products are seldom recommended for continued use and
most are intended to be removed before the engines are
put into service.
Automotive engines have always been designed and
warranted to work properly with the current available
oil at the time of manufacture. There has not been a
single off-the-shelf additive shown to perform any
beneficial function except financial gain to the
additive seller. Unlike other additives that have never
been recommended by manufacturers,
ZDDPlus™
is
a replacement for the long-used component of oil that
manufacturers once required, but over the years have
been forced to remove from the oil for the benefit of
newer cars at the expense of older
cars.
The
performance record of ZDDP is well established. We make
virtually no claims for
ZDDPlus™
,
EXCEPT that it restores the EP (extreme pressure)
function of the oil to the level originally required for
your older car. Other additives make claims so
ludicrous; they cannot be accepted based on common
sense. If the claims attributed to most additives were
even partially true they would have been part of the
standard crankcase fill directly from the manufacturers
like ZDDP has been for decades.
A quick search of Yahoo or Google will immediately
provide one with numerous sites that deal with this
subject. Most sites are credible although many date back
several years to a time when things were not as critical
as they are now in
2008.
VisitZDDP ForumFor Discussion and More Information
Because
contemporary engines with roller bearings no longer
require the additional protection of Zinc and
Phosphorus. Not true for classic cars, tractors, muscle
cars, etc. Also removing the Zinc and Phosphorus from
motor oil increases the life of the catalytic converter.
But classic cars, tractors, etc., don’t have cats! Also,
as part of its ongoing effort to reduce vehicle
emissions, the EPA has mandated that emission systems
must have a service life exceeding 120,000 miles. To
achieve this, automotive manufacturers have required oil
suppliers to remove additive packages from motor oils
that could reduce emissions compliance.
The removal of ZDDP has resulted in a clear change to that philosophy. It has
never been necessary or desirable to include additives or
supplements to any API rated oil to meet car manufacturer's
specifications or warranty requirements. In virtually all cases,
off-the-shelf additives amount to little more than automotive
snake oil. Current additive technology has yet to develop an EP
anti-wear agent as effective as ZDDP. Consequently, if these
additives actually had adequate levels of ZDDP, they would be
incompatible with modern engines and void manufacturer's
warranties.