Biofuels and Tribology: Pathways Toward Sustainable Engine
Performance
Vipal R. Panchal1, Someshwar S. Pandey2, Sajan K. Chourasia3*
Mechanical Engineering Department, Gandhinagar Institute of Technology, Gandhinagar University
382721, India
*Corresponding Author
Received: 30 October 2025; Accepted: 05 November 2025; Published: 09 December 2025
ABSTRACT
The rapid increase in automobile usage has accelerated the depletion of fossil fuels and contributed
significantly to environmental degradation. This scenario highlights the urgent need for alternative energy
resources that can meet growing energy demands while reducing harmful emissions from conventional fuels.
Among the various alternatives, biofuels have emerged as a promising option for internal combustion engines.
Numerous short-term engine tests using biofuels have shown encouraging results; however, challenges persist
in long-term engine durability tests, which often reveal issues such as excessive carbon deposition and
contamination of lubricating oils, ultimately leading to engine failure.
This review aims to evaluate the tribological feasibility of biofuels in transportation applications, as their
tribological performance plays a critical role in engine reliability and efficiency. The discussion focuses on
various tribological aspects, including material compatibility, long-term endurance, wear behavior, and
frictional characteristics. A detailed analysis of friction and wear parameters is presented, covering both
compression ignition and spark ignition engines, with particular attention to the use of biodiesels, biofuels,
and bio-oils as potential lubricants.
Rather than introducing new experimental findings, this review consolidates and critically analyzes existing
research, outlining past developments and highlighting future perspectives in the field of biofuel tribology.
INTRODUCTION
Tribology, a branch of engineering science, focuses on friction, wear, and lubrication of machine components
in relative motion. When surfaces interact with materials and the surrounding environment, parameters such
as wear, reliability, and maintenance requirements are affected—together forming the core of tribology [1]. In
mechanical systems, the primary goal of tribology is to minimize both friction and wear through effective
lubrication. Insufficient attention to tribological studies can lead to significant economic losses due to wasted
materials, excess energy consumption, and reduced equipment reliability [2].
Tribology also emphasizes selecting suitable material films for specific applications to safeguard contact
events such as rolling, sliding, and impact interactions [3]. A lack of such optimization often results in
shortened equipment life, increased downtime, and energy inefficiency [4]. For instance, the U.S. Department
of Energy has reported that reducing friction and wear in engines and drivetrain components could save
approximately $120 billion annually [5].
The core responsibility of engine tribologists is to minimize wear and friction in sliding components through
effective lubrication strategies. Improved tribological performance in engines leads to benefits such as better
fuel economy, higher brake power, lower oil consumption, reduced exhaust emissions, and longer engine life
with minimal maintenance [6]. A 10% reduction in mechanical losses has been shown to reduce fuel
consumption by 1.5%, while nearly 48% of an engine’s energy is lost as friction in components such as
pistons, bearings, valve trains, crankshafts, and transmissions [7].
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