Lubricating Oil System; Lubricating Oil Requirements - Wartsila 31 Product Manual

Wärtsilä 31 Product Guide
7.

Lubricating Oil System

7.1

Lubricating oil requirements

7.1.1 Engine lubricating oil
The lubricating oil must be of viscosity class SAE 40 and have a viscosity index (VI) of minimum
95. The lubricating oil alkalinity (BN) is tied to the fuel grade, as shown in the table below. BN
is an abbreviation of Base Number. The value indicates milligrams KOH per gram of oil.
Table 7-1
Category
A
B
C
BN 50-55 lubricants are to be selected in the first place for operation on HFO. BN 40 lubricants
can also be used with HFO provided that the sulphur content of the fuel is relatively low, and
the BN remains above the condemning limit for acceptable oil change intervals. BN 30
lubricating oils should be used together with HFO only in special cases; for example in SCR
(Selective Catalyctic Reduction) installations, if better total economy can be achieved despite
shorter oil change intervals. Lower BN may have a positive influence on the lifetime of the
SCR catalyst.
It is not harmful to the engine to use a higher BN than recommended for the fuel grade.
Different oil brands may not be blended, unless it is approved by the oil suppliers. Blending
of different oils must also be approved by Wärtsilä, if the engine still under warranty.
An updated list of approved lubricating oils is supplied for every installation.
Wärtsilä 31 Product Guide - a1 - 18 October 2016
Fuel standards and lubricating oil requirements
Fuel standard
ASTM D 975-01, GRADE NO. 1-D, 2-D, 4-D
BS MA 100: 1996 DMX, DMA, DMB
CIMAC 2003 DX, DA, DB
ISO8217: 2012(E) ISO-F-DMX, DMB
ASTM D 975-01 GRADE NO. 1-D, 2-D, 4-D
BS MA 100: 1996 DMX, DMA, DMB
CIMAC 2003 DX, DA, DB
ISO 8217: 2012(E) ISO-F-DMX - DMB
ASTM D 975-01, GRADE NO. 4-D
ASTM D 396-04, GRADE NO. 5-6
BS MA 100: 1996 DMC, RMA10-RMK55
CIMAC 2003 DC, A30-K700
ISO 8217: 2012(E) RMA10-RMK 700
7. Lubricating Oil System
Lubricating oil BN
10...30
15...30
30...55
7-1