New Methodology
On-line measurement of oil consumption
is of interest, in light of the new
environmental regulations imposed on
today's high-performance engines.
Lubricant consumption has a negative
impact on the environment, but it also
reduces the life-time of post-treatment
systems by poisoning catalysts and
clogging particle filters.
A new method was recently developed and
patented by DSi Belgium and TOTAL France
for monitoring oil consumption on
running engines. It is based on
lubricant labeling using new radiotracer
compounds, which are made representative
of the distillation interval of the base
oil.
Oil consumption measurement is performed
in the exhaust line where tracer
residues are trapped and monitored
during engine operation.
Measurement Principle
Engine oil is labeled by adding a radiotracer to the engine oil, and a
monitoring system is installed near the exhaust line where the marker will be trapped.
During engine operation the tracer is burned proportionally to the lubricant
The measurement consists of monitoring, in real-time, the amount of tracer trapped in the exhaust line.
The amplitude of the detected signal is proportional to the oil consumption.
OIL CONSUMPTION MEASUREMENT ON A V6 ENGINE
A consumption measurement was performed on a V6 PR gasoline engine.
During the experiment two probes were installed near the exhaust line - one per cylinder bank
- in order to monitor and to compare consumption of the two banks.
Oil labeling was performed using a radiotracer having a short half-life of ~40 hours.
The tracer was a mixture of organic compounds showing the same distillation interval
as the base oil contained in the lubricant.
The aim of this short experiment was to show the impact of engine speed and load on oil consumption.
Extreme conditions have also been tested, including engine knocking.
As expected, higher speeds and loads are associated to higher lubricant consumption.
It also appears clearly that consumption of cylinder bank 1 is significantly higher than bank 2.
Between t=110 and t=130 min., the sudden oil consumption increase was due to particular
conditions that induced engine knocking.