Fuel Oil and Coolant Specifications
STATEMENT OF POLICY ON FUEL AND LUBRICANT ADDITIVES
In answer to requests concerning the use of fuel and lubricating oil additives, the following excerpts have been taken
from a policy statement of General Motors Corporation:
"It has been and continues to be General Motors policy to build motor vehicles that will operate satisfactorily on the
commercial fuels and lubricants of good quality regularly provided by the petroleum industry through retail outlets. It
is accordingly contrary to the policy of General Motors to recommend the regular and continued use of
supplementary additives in such fuels and lubricants.
"This policy should not be confused with the fact that certain supplementary additives may effectively and
economically solve specific operating problems which occasionally arise in some vehicles. In such instances,
supplementary additives may be developed on the basis of suitable tests to remedy such problems without otherwise
causing harm to vehicles. These selected products are then given official GM part numbers and made available for
use in appropriate service applications.
"While General Motors Corporation assumes responsibility for the additives selected by it to remedy specific
operating problems, it cannot, of course, accept responsibility for the many other additives which are constantly
Although the stated Corporation policy is self-explanatory, the following is emphasized: Detroit Diesel Allison does not
recommend or support the use of any supplementary fuel or lubricant additives. These include all products marketed as
fuel conditioners, smoke suppressants, masking agents, reodorants, tune-up compounds, top oils, break-in oils,
raphitizers and friction-reducing compounds.
NOTE: The manufacturer's warranty applicable to Detroit Diesel engines provides In part that the
provisions of such warranty shall not apply to any engine unit which has been subject to misuse,
negligence or accident. Accordingly, malfunctions attributable to neglect or failure to follow the
manufacturer's fuel or lubricating recommendations may not be within the coverage of the warranty.
SERVICE AND INSPECTION INTERVALS
Generally, operating conditions will vary for each engine application, even with comparable mileage or hours and,
therefore, maintenance schedules can vary. A good rule of thumb for piston, ring, and liner inspections, however, would
be at 45,000 miles or 1500 hours for the first such inspection and at 30,000 miles or 1000 hour intervals thereafter. A
suggested preventive maintenance practice is a regularly scheduled testing of fuel and lubricating oils by either the oil
supplier or an independent testing laboratory. Since the oil supplier knows the physical properties of his products best
and maintains laboratories to determine practical oil drain intervals, take advantage of this service and request him to
check drained oil samples frequently and report the results to you.