Castrol Canada Inc.
Technical Service Bulletin #229
January, 1996
CD OBSOLETE JANUARY 1, 1996
The oil industry is dynamic. Specifications and test methodology are
constantly being created or revised. For example, within the last two
years, the system by which motor oils are approved was totally revamped
(API SH) and new oil standards and their associated symbols (ILSAC
GF-1) were added to the mix of existing specifications.
Once again, a change has taken place in the industry and Castrol has
responded. The API Performance Category CD has become obsolete as of
January 1, 1996. Oil marketers can no longer use the CD category
designation inside the API donut. In fact, Caterpillar, the sponsor of
the test which defines CD performance, no longer provides the hardware
necessary to run the test. Caterpillar is now committed to sponsoring
the test associated with one of the new diesel performance categories,
API CF. CF will be a category for off-road, indirect injected, heavy
duty trucks.
API CD has served an important purpose. This performance category has
long been recognized as providing additional thermal stability to
passenger car motor oils. CD performance in these oils provided
greater control of deposits and protections against obsolescence of API
CD. The industry has established a more precise test (the
Thermo-oxidation Engine Oil Simulations Test or TEOST) pertinent to
passenger car and light truck high temperature deposits. This new test
is part of current and future passenger car lubricant specifications.
Chrysler incorporated this test into its service fill engine oil
specification back in 1991. The next generation of ILSAC
specifications (GF-2) also include this test.
Castrol now markets passenger car motor oils WITHOUT the API CD
designation. These new Castrol formulations have been evaluated in the
new industry standard. All Castrol formulations exceed current and
future requirements for this measurement of thermal stability.
The deletion of API CD will in no way compromise the maximum protection
which consumers receive from GTX. We have and always will provide
maximum protection against viscosity and thermal breakdown. Passenger
cars and light trucks which call for API SG/CD or SH/CD can confidently
continue to use Castrol GTX. This applies to gasoline, diesel and
turbocharged engines. For those diesel passenger cars and trucks which
call for API CD, API CF-4 or API CG-4, Castrol RX Super 15W-40 is
recommended. Castrol RX Super 15W-40 can offer improved deposit
control and wear protections for these special diesel applications.