Kohler KD62V12A Operation And Maintenance Manual page 185

Table of Contents

SAE grade

Tab. 48: KD engine oil viscosity grade requirements

Use of 15W40 engine 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 engine 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

engine oil. Please contact your Kohler Co. representative for additional information.

Fuel sulfur content and engine oil soot

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

thus creating corrosion. Engine 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 engine oil.

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

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

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

Engine 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 engine

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

TBN ratio

The following TBN engine 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

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

Engine 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

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

Engine 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).