Volvo D12, Operator'S Manual

Page: 72 / 214

68 Oil System
Sulfur Level and TBN
Oils are available with different levels of
Total Base Number (TBN) to counteract
high sulfur levels in fuel. TBN measures an
oil’s alkalinity and ability to neutralize
acid. Normally, the higher the fuel sulfur,
the higher the TBN is needed. When US
Federal fuel is used (sulfur less than
0.05%), a minimum TBN of 5 is highly
recommended.
Sulfur creates highly acidic pollutants in
the oil that break down the additives at a
higher rate. The sulfur content in low-sulfur
fuel has been regulated to a maximum of
0.05% by weight for No. 2–D diesel fuel.
For fuels that have a sulfur content of 0.5%
by weight and above, Volvo Trucks North
America, Inc. recommends that oil change
intervals are cut in half so a shorter
mileage is run between oil changes.
Oil Additives
CAUTION
Extra oil additives must not under any
circumstances be added to any oil used.
A shortened engine life may be the re-
sult.
Using oils to the quality standards recom-
mended in this manual makes the use of
extra oil additives unnecessary, as these oils
already contain a balanced treatment of ad-
ditives. The use of extra oil additives such
as break-in oils, top oils, graphitizers and
friction reducing compounds are not neces-
sary and can even be harmful to the engine.