The Degradation of Lubricants in Gasoline Engines
Additives 2005 : Dublin 5th- 7th April 2005
John R. Lindsay Smith, Moray S. Stark,* Julian J. Wilkinson
Department of Chemistry, University of York, York YO10 5DD, UK
Peter M. Lee, Martin Priest
School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK
R. Ian Taylor
Shell Global Solutions, Chester, CH1 3SH, UK
Simon Chung
Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK
Department of Chemistry
The Degradation of Lubricants in Gasoline Engines
Additives 2005 : Dublin 5th- 7th April 2005
John R. Lindsay Smith, Moray S. Stark,* Julian J. Wilkinson
Department of Chemistry, University of York, York YO10 5DD, UK
Peter M. Lee, Martin Priest
School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK
R. Ian Taylor
Shell Global Solutions, Chester, CH1 3SH, UK
Simon Chung
Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK
mss1@york.ac.uk
www.york.ac.uk/res/gkg
The Degradation of Lubricants in Gasoline Engines
Understand Increase in Engine Friction with Oil Degradation
Department of Chemistry
The Degradation of Lubricants in Gasoline Engines
Understand Increase in Engine Friction with Oil Degradation

Sampling of Lubricant from Piston Assembly
Department of Chemistry
The Degradation of Lubricants in Gasoline Engines
Understand Increase in Engine Friction with Oil Degradation

Sampling of Lubricant from Piston Assembly

Measurement of Lubricant Flow in Engine
Department of Chemistry
The Degradation of Lubricants in Gasoline Engines
Understand Increase in Engine Friction with Oil Degradation

Sampling of Lubricant from Piston Assembly

Measurement of Lubricant Flow in Engine

Measurement of Lubricant Degradation in Engine
Department of Chemistry
The Degradation of Lubricants in Gasoline Engines
Understand Increase in Engine Friction with Oil Degradation

Sampling of Lubricant from Piston Assembly

Measurement of Lubricant Flow in Engine

Measurement of Lubricant Degradation in Engine

Chemical Mechanisms of Base Fluid Oxidation
Department of Chemistry
The Degradation of Lubricants in Gasoline Engines
Viscosity Increase in a Paris Taxi Fleet
Vk100 (cSt)
15
10
5
Oil Change
0
0
10
20
30
Oil Change
40
Distance (1000 km)
Department of Chemistry
50
60
The Degradation of Lubricants in Gasoline Engines
Engine Oil Stress Factor for Gasoline Cars : 1950 - 2000
-2
Oil Stress Factor (kW km litre )

 Oil Drain Interval 
Engine Power


Oil Stress Factor  
 Engine Displaceme nt  Sump Volume 
500
400
300
200
100
0
1940
1950
1960
1970
1980
1990
R. I. Taylor, R. Mainwaring, R. M. Mortier, Engine Lubricant Trends Since 1990,
Proc. I. Mech. E. Vol 219, Part J: J. Engineering Tribology, p 1-16, 2005
2000
© BP Castrol
Engine : Ricardo Hydra
Institute of Tribology
School of Mechanical Engineering ,The University of Leeds



Fuel Injected Gasoline
Single Cylinder
0.5 litre Capacity
Department of Chemistry
Lubrication of Engine
P. M. Lee, M. Priest, J. R. Lindsay Smith, M. S. Stark, J. J. Wilkinson, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Lubrication of Engine
P. M. Lee, M. Priest, J. R. Lindsay Smith, M. S. Stark, J. J. Wilkinson, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Lubrication of Engine
Sump 1
Valve Train
P. M. Lee, M. Priest, J. R. Lindsay Smith, M. S. Stark, J. J. Wilkinson, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Lubrication of Engine
Sump 1
Valve Train
Sump 2
Piston Assembly
Crank Shaft
P. M. Lee, M. Priest, J. R. Lindsay Smith, M. S. Stark, J. J. Wilkinson, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Lubrication of Engine
Sump 2
Piston Assembly
Crank Shaft
P. M. Lee, M. Priest, J. R. Lindsay Smith, M. S. Stark, J. J. Wilkinson, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Degradation of Lubricant
Piston Assembly
Sump
P. M. Lee, M. Priest, J. R. Lindsay Smith, M. S. Stark, J. J. Wilkinson, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Degradation of Lubricant
Piston
Piston Assembly
Sump
Sump
S. Yasutomi, Y. Maeda and T. Maeda, Kinetic Approach To Engine Oil .2.
Antioxidant Decay of Lubricant in Engine System, Ind. Eng. Chem. Prod. Res. Dev. 20 (1981) 536
Piston Assembly
R. Gamble, Influence of Lubricant Degradation on Piston Assembly Tribology,
PhD Thesis, University of Leeds, 2002
Piston Assembly
M. S. Stark, R. J. Gamble, C. J. Hammond et al., Measurement of Lubricant Flow in a Gasoline Engine,
Tribology Letters (in press) 2005
Extraction of Oil from Top Piston Ring
Top Ring Groove
1.2mm Diameter Hole
Screw with 1mm
Diameter Hole
Collar
Piston
PTFE
Tube
Top Ring Groove
PTFE Tube
Connecting
Sample Collection
Rod
R. Gamble, Influence of Lubricant Degradation on Piston Assembly Tribology,
PhD Thesis, University of Leeds, 2002
Extraction of Oil from Top Piston Ring
P. M. Lee, M. Priest, J. R. Lindsay Smith, M. S. Stark, J. J. Wilkinson, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Oil Flow in Engine
Piston
Small Volume
Short Residence Time
Flow Rate
Sump
Large Volume
Long Residence Time
S. Yasutomi, Y. Maeda and T. Maeda, Kinetic Approach To Engine Oil .2.
Antioxidant Decay of Lubricant in Engine System, Ind. Eng. Chem. Prod. Res. Dev. 20 (1981) 536
Piston Assembly Residence Time: Method
Piston
Sample Lubricant
from Piston Assembly
Add Marker to Sump
Sump
S B Saville, F D Gainey, S D Cupples, M F Fox, D J Picken,
SAE Technical Paper, International Fuels and Lubricants Meeting, Oct 10-13, 1988
Piston Assembly Residence Time: Method
[marker ]ringpack  [marker ]sump (1  exp

Time
 RingPack
)
100
Marker (%)
75
1-e-1
50
25
0
0
10RingPac
k
20
30
40
Time (arb)
S B Saville, F D Gainey, S D Cupples, M F Fox, D J Picken,
SAE Technical Paper, International Fuels and Lubricants Meeting, Oct 10-13, 1988
50
Piston Assembly Residence Time : 60 sec
[marker ]ringpack  [marker ]sump (1  exp

Time delay
 RingPack
)
100
Marker (%)
75
50
25
0
0
1
2
3
4
5
Time (min)
Conditions : 1500 rpm, 50 % Load. Lubricant : XHVITM 8.2 only
M. S. Stark, R. J. Gamble, C. J. Hammond et al., Measurement of Lubricant Flow in a Gasoline Engine,
Tribology Letters (in press) 2005
Piston Flow Rate: Method
Piston
Small Volume
Short Residence Time
Flow Rate
Sump
Large Volume
Long Residence Time
S. Yasutomi, Y. Maeda and T. Maeda, Kinetic Approach To Engine Oil .2.
Antioxidant Decay of Lubricant in Engine System, Ind. Eng. Chem. Prod. Res. Dev. 20 (1981) 536
Oxidation Chemistry
Hydrocarbon
Base Fluid
(schematic)
Department of Chemistry
Oxidation Chemistry
Hydrocarbon
Base Fluid
Hydroperoxides
O
O
H
Department of Chemistry
Oxidation Chemistry
Hydrocarbon
Base Fluid
Hydroperoxides
O
O
H
O
Alcohols
Department of Chemistry
H
Oxidation Chemistry
Hydrocarbon
Base Fluid
Hydroperoxides
O
O
H
O
O
O H
Alcohols
Department of Chemistry
Carboxylic Acids
+
Ketones
Oxidation Chemistry
Hydrocarbon
Base Fluid
Hydroperoxides
O
O
H
O
O
O H
Alcohols
Carboxylic Acids
+
Ketones
Infrared Spectroscopy
of Carbonyl Group
Department of Chemistry
Comparison of Sump and Ring Pack
-3
0.3
8
6
0.2
4
0.1
2
TAN (Calculated)
Carbonyl (10 mol / litre)
10
Ring Pack
Sump (x10)
0
0
60
120
0.0
180
Time (mins)
Conditions : 2000 rpm, 50 % Load
M. S. Stark, J. J. Wilkinson, P. M. Lee, J. R. Lindsay Smith, M. Priest, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Comparison of Sump and Ring Pack
-3
0.3
8
6
0.2
4
0.1
2
TAN (Calculated)
Carbonyl (10 mol / litre)
10
Ring Pack
Sump (x10)
0
0
60
120
0.0
180
Time (mins)
Conditions : 2000 rpm, 50 % Load
M. S. Stark, J. J. Wilkinson, P. M. Lee, J. R. Lindsay Smith, M. Priest, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Calculation of Sump Residence Time
[Product ]RingPack
 SUMP 
 d [Product ]Sump 


dt


-3
0.3
8
6
0.2
4
0.1
2
TAN (Calculated)
Carbonyl (10 mol / litre)
10
Ring Pack
Sump (x10)
0
0
60
120
0.0
180
Time (mins)
M. S. Stark, J. J. Wilkinson, P. M. Lee, J. R. Lindsay Smith, M. Priest, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Calculation of Sump Residence Time
[Product ]RingPack
 SUMP 
 d [Product ]Sump 


dt


 SUMP  49  5 hours
-3
0.3
8
6
0.2
4
0.1
2
TAN (Calculated)
Carbonyl (10 mol / litre)
10
Ring Pack
Sump (x10)
0
0
60
120
0.0
180
Time (mins)
M. S. Stark, J. J. Wilkinson, P. M. Lee, J. R. Lindsay Smith, M. Priest, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Calculation of Sump Residence Time
[Product ]RingPack
 SUMP 
 d [Product ]Sump 


dt


 SUMP  19  2 hours litre -1
-3
0.3
8
6
0.2
4
0.1
2
TAN (Calculated)
Carbonyl (10 mol / litre)
10
Ring Pack
Sump (x10)
0
0
60
120
0.0
180
Time (mins)
M. S. Stark, J. J. Wilkinson, P. M. Lee, J. R. Lindsay Smith, M. Priest, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Sump Residence Time (hours/litre)
Sump Residence Time : Engine Speed
40
30
20
10
0
0
1000
Engine Speed (rpm)
2000
Conditions : 1000 - 2000 rpm, 50 % Load
M. S. Stark, J. J. Wilkinson, P. M. Lee, J. R. Lindsay Smith, M. Priest, R. I. Taylor and S. Chung,
Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, Elsevier, 2005 (in press)
Characterisation of Gasoline Engine
Piston Assembly
Residence Time
Volume of Oil


Flow Rates
Returning to Sump
Oil Loss

1 cm3 min-1 cylinder-1
 0.05 cm3 min-1 cylinder-1
Sump
Residence Time

60 seconds
1 cm3 cylinder-1
20 hours litre-1
M. S. Stark, R. J. Gamble, C. J. Hammond, et al., Tribology Letters, (in press) 2005
M. S. Stark, et al., Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, (in press) 2005
Characterisation of Gasoline Engine
Piston Assembly
Residence Time
Volume of Oil
Temperature
 60 seconds

1 cm3 cylinder-1
 200 °C
Flow Rates
Returning to Sump
Oil Loss

1 cm3 min-1 cylinder-1
 0.05 cm3 min-1 cylinder-1
Sump
Residence Time
Temperature


20 hours litre-1
70 °C
M. S. Stark, R. J. Gamble, C. J. Hammond, et al., Tribology Letters, (in press) 2005
M. S. Stark, et al., Proceedings of the 31st Leeds-Lyon Symposium on Tribology, Sept 2004, (in press) 2005
Hydrocarbon Degradation Chemistry
No. of Carbons
(random example)
Department of Chemistry
XHVI™ 8.2 (average)
39
Models of Hydrocarbon Base-Fluids
No. of Carbons
(random example)
Department of Chemistry
XHVI™ 8.2 (average)
39
Hexadecane
16
Traditional Alkane Oxidation Mechanism
+
Department of Chemistry
.
ROO
.
+
ROOH
Traditional Alkane Oxidation Mechanism
+
.
Department of Chemistry
.
.
+
ROO
O
+
O2
O
ROOH
Traditional Alkane Oxidation Mechanism
+
.
.
+
ROO
O
.
+
ROOH
O
O2
H
O
O
O
+
Department of Chemistry
RH
O
+
R
.
Traditional Alkane Oxidation Mechanism
+
.
.
+
ROO
O
.
+
ROOH
O
O2
H
O
O
O
+
RH
O
.
+
R
+
HO
H
O
O
Department of Chemistry
O
Traditional Alkane Oxidation Mechanism
+
.
.
+
ROO
O
.
+
ROOH
O
O2
H
O
O
O
+
O
RH
.
+
R
+
HO
+
R
H
O
O
O
H
O
O
+
Department of Chemistry
RH
.
Traditional Alkane Oxidation Mechanism
+
.
.
+
ROO
O
.
+
ROOH
O
O2
H
O
O
O
+
O
RH
.
+
R
+
HO
+
R
+
H2O
H
O
O
O
H
O
O
+
RH
.
H
O
O
Department of Chemistry
O
Hexadecane Oxidation
+ RO2. + O2
O
Jensen et al, J. Am. Chem. Soc., 103, 1742 1981 and 101, 7574 1979
O
H
(Conditions : 120 – 180 °C)
Hexadecane Oxidation
+ RO2. + O2
O
O
H
.
O
O
H
Jensen et al, J. Am. Chem. Soc., 103, 1742 1981 and 101, 7574 1979
(Conditions : 120 – 180 °C)
Hexadecane Oxidation
+ RO2. + O2
O
O
H
+ O2
O
O
O
O
H
Jensen et al, J. Am. Chem. Soc., 103, 1742 1981 and 101, 7574 1979
(Conditions : 120 – 180 °C)
Hexadecane Oxidation
+ RO2. + O2
O
O
H
+ O2
O
O
O
O
O
O
H
+ RH
Jensen et al, J. Am. Chem. Soc., 103, 1742 1981 and 101, 7574 1979
O
O
H
H
(Conditions : 120 – 180 °C)
Hexadecane Oxidation
+ RO2. + O2
O
O
H
+ O2
O
O
O
O
O
O
H
+ RH
O
O
H
H
O
O
H
Jensen et al, J. Am. Chem. Soc., 103, 1742 1981 and 101, 7574 1979
(Conditions : 120 – 180 °C)
Models of Hydrocarbon Base-Fluids
No. of Carbons
(random example)
Department of Chemistry
XHVI™ 8.2 (average)
39
Hexadecane
16
Pristane
19
Models of Hydrocarbon Base-Fluids
No. of Carbons
(random example)
Department of Chemistry
XHVI™ 8.2 (average)
39
Hexadecane
16
Pristane
19
Squalane
30
Tertiary Carbons in Base-Fluids
tertiary C (%)
25
20
15
10
5
Group I
Group II
Group III
hydrocracked
Group III
isodewaxed
PAO
0
range
S. McKenna, M. Casserino, K. Ratliff, Comparing the Tertiary Carbon Content of PAO’s and Mineral Oils
Presentation, STLE Annual Meeting, Houston, 2002
Tertiary Carbons in Base-Fluids
tertiary C (%)
25
20
15
10
5
Pristane
Squalane
Group I
Group II
Group III
hydrocracked
Group III
isodewaxed
PAO
0
range
S. McKenna, M. Casserino, K. Ratliff, Comparing the Tertiary Carbon Content of PAO’s and Mineral Oils
Presentation, STLE Annual Meeting, Houston, 2002
Bench-Top Reactors
Department of Chemistry
Oxidation of Pristane : GC Analysis (polar)
Micro-reactor conditions: 1000 mbar O2, 200 ºC, 1 minute
GC conditions: Carbowax column, 50-250 ºC, 4 ºC min-1
OH
OH
Solvent (CH3OH)
time (min)
OH
Department of Chemistry
OH
Oxidation of Pristane : GC (non-polar)
Micro-reactor conditions: 1000 mbar O2, 200 ºC, 1 minute
GC conditions: ZB-5 column, 50-300 ºC, 6 ºC min-1
time (min)
Department of Chemistry
impurity
Oxidation of Pristane : Ketones
O
Ketones
time (min)
Department of Chemistry
impurity
Oxidation of Pristane : Ketones
O
O
O
O
time (min)
Department of Chemistry
impurity
Oxidation of Pristane : Alkanes
Alkane
time (min)
Department of Chemistry
Oxidation of Pristane : Fragmentation
O
O
.
+
RH
time (min)
Department of Chemistry
Oxidation of Pristane : Fragmentation
O
O
+
time (min)
Department of Chemistry
Oxidation of Pristane : Fragmentation
O
+
O
time (min)
Department of Chemistry
Reactions of Alkyl Radicals
+
RH
.
Department of Chemistry
+
.
R
Reactions of Alkyl Radicals
+
RH
+
.
R
.
+ O2
Department of Chemistry
O
O
.
Reactions of Alkyl Radicals
+
RH
+
.
R
.
+ O2
Department of Chemistry
O
O
.
+
RH
O
O
H
Reactions of Alkyl Radicals
+
RH
+
.
R
.
+ O2
O
O
.
+
RH
O
O
O
H
H
Department of Chemistry
+
H2O
Formation of Carboxylic Acids
+
+
RH
.
R
.
+ O2
O
O
.
+
RH
O
O
O
H
H
O
+ RO2.
H
Department of Chemistry
.
O
+
H2O
Formation of Carboxylic Acids
+
+
RH
.
R
.
+ O2
O
O
.
+
RH
O
O
O
H
H
O
+ RO2.
H
Department of Chemistry
.
O
+ O2
O
O
.
O
+
H2O
Formation of Carboxylic Acids
+
+
RH
.
R
.
+ O2
O
O
.
+
RH
O
O
O
H
+
H
O
+ RO2.
H
Department of Chemistry
.
O
+ O2
O
O
.
O
+
RH
O
O
O
H
H2O
Formation of Carboxylic Acids
+
+
RH
.
R
.
+ O2
O
O
.
+
RH
O
O
O
H
+
H
O
+ RO2.
H
.
O
+ O2
O
O
.
O
+
RH
O
O
O
O
O
Department of Chemistry
H
H
H2O
Oxidation of Pristane : Alkenes
time (min)
Department of Chemistry
Possible Mechanisms of Alkene Formation
+ H2O
O
Department of Chemistry
H
Possible Mechanisms of Alkene Formation
O
H
+
O
Department of Chemistry
H
O
Possible Mechanisms of Alkene Formation
O
H
+
O
O
+ H2O
O
Department of Chemistry
H
O
Possible Mechanisms of Alkene Formation
O
H
+
O
O
O
+ H2O
H
O
Department of Chemistry
H
O
O
Possible Mechanisms of Alkene Formation
O
H
+
H
O
O
O
+ H2O
H
O
Department of Chemistry
O
H
O
O
O
Alkenes and Polymerisation
(+ ROO.)
Very Easy
.
Monomer
Department of Chemistry
Alkenes and Polymerisation
(+ ROO.)
Very Easy
.
Monomer
.
+
Department of Chemistry
.
Alkenes and Polymerisation
(+ ROO.)
Very Easy
.
Monomer
.
.
+
+ R.
+
R
.
Department of Chemistry
Conclusions

Sampling of Lubricant from Piston Assembly

Measurement of Lubricant Flow in Engine

Measurement of Lubricant Degradation in Engine

Chemical Mechanisms of Base Fluid Oxidation
Department of Chemistry
Project Posters

Peter Lee
Lubricant Degradation Studies Using a Single Cylinder Research Engine
• Engine Set-up and Modifications

Julian Wilkinson
Understanding Lubricant Degradation in Gasoline Engines
• Oxidation Mechanisms of Model Base Fluids
• Viscosity Change During Hydrocarbon Oxidation
Department of Chemistry
Acknowledgements
University of Leeds
Richard Gamble, Chris Taylor, D. Desmonteix
University of York
Chris Hammond, David Waddington, Trevor Dransfield
Shell
Harold Gillespie, Eiji Nagatomi, Richard Dixon
Infineum
Bénédicte Menguy
Financial Support
Shell Global Solutions,
Moray Stark
Infineum,
mss1@york.ac.uk
EPSRC
www.york.ac.uk/res/gkg