DRIVING AUTO PERFORMANCE
THROUGH LUBRICANT SELECTION
How Lubricants Can Reduce Component Failures and Extend Vehicle Life

Driving Auto Performance Through Lubricant Selection

In the 1960s the average underhood inlet air temperature
to the alternator was below 100 °C (210 °F). By the early
2000s that jumped to more than 120 °C (250 °F)i, andtoday, underhood operating temperatures can approach
200 °C (392 °F). Finding a lubricant that can withstand therising temperatures and harsh conditions over an extended
period is critical to optimal vehicle performance.
High performance lubricants, such as perfluoropolyethers (PFPEs), excel in theseconditions, creating a ripple effect of value: reducing component failures, extending
vehicle life, reducing warranty claims, improving quality and customer loyalty, andincreasing profitability.

Average Underhood Inlet Air Temperature
200 °C

150 °C

100 °C

50 °C

0 °C

1960

2015

Mike Bradfield, “Thermal Design Challenges in Automotive Alternator Power Electronics,” Electronics Cooling, May 2002
(http://www.electronics-cooling.com/2002/05/thermal-design-challenges-in-automotive-alternator-power-electronics/).

i.

2Driving Auto Performance Through Lubricant Selection

Understanding the Challenges of Temperature and Performance
Automotive interior and underhood temperatures varysignificantly—from below -50 °C (-58 °F) to nearly 200°C (392 °F), and many applications generate additional
heat above the ambient temperature. Over time, thesetemperature extremes can cause lubricants to degrade,
resulting in component failures.
For example, most standard petroleum-based greases
begin to oxidize and degrade above 100 °C (212 °F).
Synthetic lubricants (e.g., esters, polyalkylene
glycols, and polyalphaolefins) can survive at higher
temperatures, but the PFPE lubricants provide thehighest performance, withstanding temperatures
above 300 °C (572 °F).
Lubricant performance also varies significantly basedon loads, speeds, and environmental conditions—
including exposure to corrosive road deicers, fuel, andother materials.
During a standard bearing endurance test (ASTMD-3336) at 10,000 revolutions per minute, petroleumbased greases last only a few hundred hours, while one
PFPE grease lasted more than 25,000 hours.
Given the unique performance capabilities of eachlubricant, understanding the strengths and weaknessesof each lubricant class can help maximize performance.

Most standard petroleum-based greases begin to oxidize
and degrade above 100 °C (212 °F). Synthetic lubricants(e.g., esters, polyalkylene glycols, and polyalphaolefins) cansurvive at higher temperatures, but the PFPE lubricants
provide the highest performance, withstanding temperatures
above 300 °C (572 °F).

Comparison of Temperature Limits
Temperature oC-60 -40 -20 0 20 40 60 80 100

140 160 180 200

240

280

PetroleumPAO
Esters
PAG
Silicone

Krytox™

Low Temperature Range

Continuous ServiceHigh Temperature Range

3320

Driving Auto Performance Through Lubricant Selection

The Automotive Lubricant Landscape
Here’s a capability overview of common automotive lubricant classifications:
Perfluoropolyethers
PFPEs are a class of synthetic lubricants used in demanding
applications due to their combination of physical and chemical
properties. PFPEs offer excellent thermal and chemical
stability, low volatility, and unmatched lubricity at extreme
temperatures. PFPEs are the ideal lubricant when highperformance is needed in an extreme environment, and canalso be the lubricant of choice for applications requiring otherproperties, such as chemical inertness and extreme pressure
capability. Vehicle warranties can typically be extended dueto the long-lasting performance of these lubricants.
MineralMineral lubricants offer excellent hydrolytic stability and goodseal material compatibility, lubricating ability, and toxicity.
However, mineral lubricants provide poor fire resistance andonly moderate thermal and oxidation stability.
Polyalphaolefins (PAOs)
PAO lubricants boast excellent hydrolytic stability and toxicity,
along with above average oxidation stability, volatility, sealcompatibility, and lubricating ability. Yet, the lubricant haslimited capabilities across temperature extremes, with onlymoderate thermal stability and poor fire resistance.

Diester
Diester lubricants provide good thermal, oxidation, andhydrolytic stability, as well as above average lubricating
ability, toxicity, and volatility. However, the lubricant has onlymoderate fire resistance and poor seal material compatibility.
Polyol Ester
Polyol ester lubricants have similar performance capabilities todiesters, but with improved hydrolytic stability, slightly stronger
thermal stability, and overall lubricating ability.
Silicones
Silicone lubricants have good chemical inertness, thermal
stability, and low volatility, making them a good lubricant
choice for certain applications. However, their lubricating
film-forming capability is low; and, consequently, silicone
lubricants cannot support high loads. Silicones are also
known to migrate easily, which can cause serious concerns ina vehicle assembly plant, particularly around paint lines.

4Driving Auto Performance Through Lubricant Selection
Lubricant Capability Comparison
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EXCELLENT

5Driving Auto Performance Through Lubricant Selection

A Deeper Look at the Unique Properties of PFPEs
Wide temperature range

Chemical compatibility

PFPEs have proven they perform well at extreme temperatures,from -75 °C to greater than 400 °C (-103 °F to 752 °F).
This is a broader temperature range than any other class oflubricants. The volatility of PFPEs at elevated temperatures isvery low, so the lubricant stays in place and does not dry out
in service.

Given the harsh automotive environment, the chemical
inertness of PFPEs provides a significant advantage.
Compatible with a wide range of materials—including all
automotive plastics, elastomers, metals, fabrics, paint, clear
coat, fuel, and even other lubricants—PFPEs outlast andoutperform all alternatives in compatibility tests.
Excellent oxidative stability
Generally, high temperatures, water, acids, and catalysts
increase the rate of oxidation, creating a corresponding
decrease in the life of the lubricant, and, as a result, component
life. In contrast, PFPEs do not oxidize and do not thermallydegrade, even at service temperatures well above 400 °C(752 °F)—helping PFPEs outlast other lubricants.
Long lubrication life across wide viscosity range

Hydrocarbon

PFPE(Krytox™ GPL 227)

In an oven at 232 °C (448 °F) for 40 hours, hydrocarbon(left) lost 40% of weight and developed tar and significant
hardening. PFPE (right) remained unchanged, retaining
all lubrication properties, and still meeting new productspecifications.

The ability of a lubricant to support a load depends significantly
on viscosity. If viscosity is too low, the load will overcome thelubricating film and failure will occur. Conversely, if viscosity
is too high, excessive heat can be generated in the shearingof the lubricant, particularly in high-speed applications. Whilehydrocarbon lubricants displayed signs of wear and early failurein extreme pressure testing, PFPEs reached the maximum test
loads without failure.

6Driving Auto Performance Through Lubricant Selection

Where to Use PFPEs
The many automotive applications of PFPEs generally fall into two categories:

Under the Hood

Vehicle Interior and Noise, Vibration, and Harshness

Underhood temperatures are gradually rising as aerodynamics
dictate tighter packaging and large engines are being replaced bysmaller turbocharged and supercharged engines for improved fuelefficiency. With ambient temperatures under the hood exceeding
120 °C (248 °F), PFPEs have a growing list of automotiveapplications, including:

PFPEs are particularly effective at eliminating squeaks andassociated noises on and inside vehicles without any concern
over material compatibility. PFPEs significantly reduce frictionand energy buildup between surfaces that can lead to noises
when the parts rub against each other. Application categories
include:• Overrunning decouplers for alternator drive pulleys• Interior plastics• Front end accessory drive (FEAD) tensioners and idlers		

• Instrument panels• Throttle body bearings		

• Door trim

• EGR valves		• Center and overhead consoles• Variable-geometry intake manifold valves• Leather seats and seat latches• Fuel system emission control valves• Electric switches• Electric cooling system pumps and valves• Weatherstrips and seals• Ignition system boots7

Driving Auto Performance Through Lubricant Selection
About Krytox™ PFPE Lubricants
Krytox™ lubricants are Chemours’ line of high quality
PFPE oils and greases first developed by DuPont. Krytox™
lubricants have been proven to offer long-term performanceand superior value. These lubricants are PFPEs, resulting in
exceptional chemical stability. Therefore, they are thermallystable, nonflammable, and insoluble in water, acids, bases,
and most organic and all non-fluorinated solvents.
Chemours is ISO 9001and ISO 14001 certified and NSF
H-1 for selected grades of Krytox™ lubricants.
For more products and information, visit
Krytox.com/AutoLube, or call a Krytox™ lube
technical expert:

In the U.S. and Canada ....... 1-800-424-7502
Outside the U.S. ...................... 1-302-773-1000

The attributes of Krytox™ lubricants include:
Performance over a wide temperature range
Extreme heat or cold have no effect on the lubricity of these lubricants,
effective from -75 °C to greater than 400 °C (-103 °F to 752 °F),
depending upon operating conditions and product grade.
Resistant to chemical attack
Krytox™ lubricants withstand fuel, coolant, brake fluid, engine oil, washer
solvent, and even battery acid.
Low evaporation
Krytox™ lubricants—within the recommended temperature ranges—
experience almost zero evaporation or chemical changes over the many
years of a vehicle’s service life.
Compatibility
Krytox™ lubricants won’t harm painted surfaces, plastics, orelastomers. They are compatible with almost every material they
may contact.
Outstanding dielectric properties
Krytox™ lubricants are good insulators and have become thelubricant of choice for electrical applications.

Performance Lubricants
The information set forth herein is furnished free of charge and based on technical data that Chemours believes to be reliable. Chemours makes no warranties, express orimplied, and assumes no liability in connection with any use of this information. Nothing herein is to be taken as a license to operate under or a recommendation to infringe
any patents or trademarks.
©2017 The Chemours Company FC, LLC. Krytox™ and any associated logos are trademarks or copyrights of The Chemours Company FC, LLC. Chemours™ and theChemours Logo are trademarks of The Chemours Company.
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