Kohler KD103V20 Operation And Maintenance Manual page 142

Table of Contents

Maintenance

Lubricants and operating fluids

SAE grade

Tab. 34: KD lubricating oil viscosity grade requirements

Use of 15W40 lubricating oil presents some restrictions in cold environments.

Kohler KD diesel engines are designed to start with an ambient temperature above

-10 °C (14 °F) with 5W40 or 10W40 lubricating oils. Specific additional devices should be

considered for application intended to start at a temperature below -10 °C (14 °F) or when using

a 15W40 lubricating oil. Please contact your Kohler Co. representative for additional informa‐

tion.

Fuel sulfur content and lubricating oil soot

Fuel sulfurs impact diesel engine hardware by developing sulfuric acids during combustion,

thus creating corrosion. Lubricating oil embeds basic compounds (detergents) to neutralize

these acids. The TBN (Total Base Number) measures the detergent content by providing an

index of basicity for the lubricating oil.

With generalization of low sulfur content fuels and the associated evolution of lubricating oils,

the TBN is no more sufficient to monitor operating oil status. The TAN (Total Acid Number) is

also needed to get an accurate picture of the lubricating oil condition.

Lubricating oil soot is a by-product of the combustion comprised of roughly 98% of carbon in

mass. It forms on the coolest part of the combustion chamber. Then soot is dragged into the oil

by the piston rings or migrates to the crankcase through the crankcase breather system.

TBN ratio

The following TBN lubricating oils are approved for use in Kohler KD diesel engines.

– When diesel engine is operated with low sulfur content fuels (sulfur content lower than

0.5%):

TBN must be higher than 8 mgKOH/g and the soot (S

– When diesel engine is operated with sulfur content fuels between 0.5% and 1%:

TBN must be higher than 10 mgKOH/g and the soot (S

Lubricating oil change interval must be reduced according to the following table.

Oil change intervals must be confirmed through analysis process.

– When diesel engine is operated with sulfur content fuels between 1.0% and 1.5%:

TBN must be higher than 12 mgKOH/g and the soot (S

Lubricating oil change interval must be reduced according to the following table.

Oil change intervals must be confirmed through analysis process.

As a reminder, Kohler KD diesel engines must not be operated with fuels having a sulfur content

higher than 1.5% (15000 ppm).

Emission-certified engines must not be operated with fuel having a sulfur content higher than

0.0015% (15 ppm).