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Viewing 1 to 30 of 197
2017-10-08
Technical Paper
2017-01-2351
Bernardo Tormos, Guillermo Miró, Leonardo Ramirez, Tomás Pérez
Abstract Low viscosity engine oils are considered a feasible solution for improving fuel economy in internal combustion engines (ICE). So, the aim of this study was to verify experimentally the performance of low viscosity engine oils regarding their degradation process and possible related engine wear, since the use of low viscosity engine oils could imply higher degradation rates and/or unwanted wear performance. Potential higher wear could result in a reduction in life cycle for the ICE, and higher degradation rates would be translated in a reduction of the oil drain period, both of them non-desired effects. In addition, currently limited data are available regarding “real-world” performance of low viscosity engine oils in a real service fleet.
2017-10-08
Technical Paper
2017-01-2353
Bernardo Tormos, Leonardo Ramirez, Guillermo Miró, Tomás Pérez
Abstract One of the most interesting alternatives to reduce friction losses in the internal combustion engines is the use of low viscosity engine oils. Recently, a new engine oil category focused fuel economy, has been released in North America encouraging the use of these oils in the heavy-duty vehicles’ segment. This paper presents the results of a comparative test where the differences in fuel consumption given by the use of these oils are shown. The test included 48 buses of the urban public fleet of the city of Valencia, Spain. The selected vehicles were of four different bus models, three of them fueled with diesel and the other one with compressed natural gas (CNG). Buses’ fuel consumption was calculated on a daily basis from refueling and GPS mileage. After three oil drain intervals (ODI), the buses using low viscosity engine oils presented a noticeable fuel consumption reduction. These results bear out the suitability of these oils to palliate engine inefficiencies.
2017-10-08
Journal Article
2017-01-2346
Hong Liu, Jiajia Jin, Hongyu Li, Kazuo Yamamori, Toyoharu Kaneko, Minoru Yamashita, Liping Zhang
Abstract It has been long established fact that fuel economy is a key driving force of low viscosity gasoline engine oil research and development considered by the original equipment manufacturers (OEMs) and lubricant companies. The development of low viscosity gasoline engine oils should not only focus on fuel economy improvement, but also on the low speed pre-ignition (LSPI) prevention property. In previous LSPI prevention literatures, the necessity of applying Ca/Mg-based detergents system in the engine oil formulations was proposed. In this paper, we adopted a specific Group III base oil containing Ca-salicylate detergent, borated dispersant, Mo-DTC in the formulation and investigated the various effects of Mg-salicylate and Mg-sulfonate on the performance of engine oil. It was found that Mg-sulfonate showed a significant detrimental impact on silicone rubber compatibility while the influence from Mg-salicylate remains acceptable.
2017-01-10
Technical Paper
2017-26-0052
Gopalakrishna Acharya, K.A. Subramanian, R K Malhotra
In India, there is a large population of heavy duty diesel engine powered vehicles such as trucks and buses. Buses are operated under normal speed & load conditions whereas trucks are generally overloaded with high severity on engine oil and lugging operation is common. Higher loading of soot in engine oil results in increase in viscosity of oil and also affects the friction properties and also wear in engine components. The engine oil keep the soot dispersed in order to meet the basic function of lubricating and also keep the engine components clean.
2016-10-17
Technical Paper
2016-01-2315
Xiaobo Shen, Rajiv Taribagil, Stuart Briggs, Isabella Goldmints
Abstract An unprecedented global focus on the environment and greenhouse gases has driven recent government regulations on automotive emissions across the globe. To achieve this improvement, Original Equipment Manufacturers (OEMs) have advocated a progressive move towards the use of low viscosity grade oils. However, the use of lower viscosity grades should not compromise engine durability or wear protection. Viscosity modifiers (VM) - polymeric additive components used to tailor the lubricant’s viscometric properties - have been viewed as a key enabler for achieving the desirable balance between fuel economy and engine durability performance. Self-assembling diblock copolymers represent a unique class of VMs, which deliver superior shear stability due to their tunable association/dissociation in the lubricating oil. Superior shear stability ensures that the oil viscosity and its ability to offer reliable engine protection from wear is retained over the life of the oil in the engine.
2016-04-05
Technical Paper
2016-01-0899
Takashi Hoshino, Farrukh Qureshi, Nicholas Virostko, Elizabeth Schiferl, Ananda Gajanayake, Motoji Hiroki, Tomoya Higuchi, Keita Ishizaki
Abstract The growing need for improved fuel economy is a global challenge due to continuously tightening environmental regulations targeting lower CO2 emission levels via reduced fuel consumption in vehicles. In order to reach these fuel efficiency targets, it necessitates improvements in vehicle transmission hardware components by applying advanced technologies in design, materials and surface treatments etc., as well as matching lubricant formulations with appropriate additive chemistry. Axle lubricants have a considerable impact on fuel economy. More importantly, they can be tailored to deliver maximum operational efficiency over specific or wide ranges of operating conditions. The proper lubricant technology with well-balanced chemistries can simultaneously realize both fuel economy and hardware protection, which are perceived to have a trade-off relationship.
2016-04-05
Journal Article
2016-01-0894
Kenji Matsumoto, Hironori Harada, Yuki Ono, Yuji Mihara
Abstract A simple method is frequently used to calculate a reciprocating engine’s bearing load from the measured cylinder pressure. However, it has become apparent that engine downsizing and weight reduction cannot be achieved easily if an engine is designed based on the simple method. Because of this, an actual load on a bearing was measured, and the measured load values were compared with a bearing load distribution calculated from cylinder pressure. As a result, it was found that some of actual loads were about half of the calculated ones at certain crank angles. The connecting rod’s elastic deformation was focused on as a factor behind such differences, and the rod’s deformation due to the engine’s explosion load was studied. As a result, it was found that the rod part of the engine’s connecting rod was bent by 0.2 mm and became doglegged. Additional investigation regarding these findings would allow further engine downsizing.
2016-04-05
Journal Article
2016-01-0896
Masami Ishikawa, Kazuo Yamamori, Satoshi Hirano, Teri Kowalski, James Linden
Abstract Fuel economy improvement has been one of the most important challenges for the automotive industry, and the oil and additive industries. The automotive, oil, and additive industries including related organizations such as SAE, ASTM, and testing laboratories have made significant efforts to develop not only engine oil technologies but also engine oil standards over decades. The API S category and ILSAC engine oil standard are well known and widely used engine oil specifications [1] [2]. The development of an engine oil standard has important roles to ensure the quality of engine oils in the market and encourage industries to improve the engine oil performance periodically. However, the progress of technology advancement can go faster than the revision of engine oil standard. An introduction of new viscosity grades, SAE 0W-16 and 5W-16 is one good example. The 16 grade was added into the SAE J300 standard that defines viscosity grades for engine oils in April 2013 [3].
2016-04-05
Technical Paper
2016-01-0484
Chad W. Chichester
Abstract Silicone fluids are known to have high Viscosity Indices (VI), and high Oxidation Onset Temperatures (OOT). Silicone VI and OOT characteristics make these fluids appealing for use as lubricants in high temperature applications, and where lubricant longevity is desired. Despite thermal and oxidative benefits, silicones lubricants have a reputation as being poor lubricants in metal-to-metal applications, and are typically only selected for use in plastic applications. Most industrial knowledge about silicone lubricants is based on characteristics of PolyDiMethyl Siloxanes (PDMS), in which case, lubricity limitations do exists. However, there are other silicone based lubricating fluid technologies, that have been commercially available for decades, that far exceed known lubricity performance of PDMS, and in some ways can rival traditional synthetic hydrocarbon.
2016-03-14
Journal Article
2016-01-9071
Arthur Andrews, Raymond Burns, Richard Dougherty, Douglas Deckman, Mrugesh Patel
Abstract Low speed pre-ignition (LSPI) is a type of engine knocking specific to turbocharged direct injection engines. There are numerous factors that affect the amount of LSPI produced by an engine. Some of these factors are related to engine hardware; others are specific to the fuel and engine oil. In this paper we focus on the effect of the engine oil base stock on LSPI. We conducted experiments in a stationary engine operating at conditions chosen to accentuate pre-ignition. Our results indicate that base stock viscosity has a statistically significant effect on the amount of low speed pre-ignition. Directionally, we found that engine oils formulated with higher viscosity base stocks produced more pre-ignition events. We measured the effect of base stock quality (defined by either Viscosity Index or concentration of aromatic species) to be small and statistically insignificant in our experimental data.
2015-09-29
Technical Paper
2015-01-2876
Shankar Patil, P Mahesh, Krishnan Sadagopan, Senniappan Arunachalam Gokhul
Abstract In tropical conditions, twelve numbers of ten ton intermediate commercial vehicles run at regular interval from zero to 60000 kilometer. Vehicle field run data were composed and analyzed with intended duty cycle for engine oil drain life estimation. The intermediate commercial vehicle trucks with sump capacity 0.083- 0.104 liter/HP and SAE 15W40 viscosity of oil meeting API CH-4, API CI-4+ from group-I and group-II base stocks are considered. The engine wear is more a function of silica concentration, load factor and age than the API category of the oil. Oil drain interval is found to be proportional to the sump volume for the same stress on the oil. Iron concentration and kinematic viscosity decide to be useful oil life with respect to the limits fixed by the engine manufacturer. In tropical conditions, field trials are carried out on 10 ton payload vehicles at higher temperature, humidity, dust levels and payload factor.
2015-09-01
Technical Paper
2015-01-2048
Jack Zakarian, Michael E. Webb, Brett Hunter
The Viscosity Index (VI, ASTM D2270) has a long and widespread history as a rating scale for the viscosity-temperature behavior of lubricants. However, the method has serious technical deficiencies which can lead to misleading conclusions. We have examined alternatives to the VI scale in an effort to more accurately characterize the viscometric behavior of modern lubricants, which are formulated with highly refined base oils and advanced polymers. We have found that the VI method can actually mask improved viscosity-temperature behavior for certain highly additized polymer-containing lubricants. We examine two different methods, the Roelands Slope Index and the Proportional VI, as an alternative to VI. It is important for lubricant developers and consumers to be aware of the limitations of the VI scale in describing the viscometric qualities of modern, high performance lubricants.
2014-10-13
Technical Paper
2014-01-2859
Oliver P. Taylor, Richard Pearson, Richard Stone, Phil Carden, Helen Ballard
Abstract Most major regional automotive markets have stringent legislative targets for vehicle greenhouse gas emissions or fuel economy enforced by fiscal penalties. Large improvements in vehicle efficiency on mandated test cycles have already taken place in some markets through the widespread adoption of technologies such as downsizing or dieselization. There is now increased focus on approaches which give smaller but significant incremental efficiency benefits such as reducing parasitic losses due to engine friction. Fuel economy improvements which achieve this through the development of advanced engine lubricants are very attractive to vehicle manufacturers due to their favorable cost-benefit ratio. For an engine with components which operate predominantly in the hydrodynamic lubrication regime, the most significant lubricant parameter which can be changed to improve the tribological performance of the system is the lubricant viscosity.
2014-10-13
Journal Article
2014-01-2791
Jun Cui, Sonia Oberoi, Isabella Goldmints, Stuart Briggs
Abstract Global environmental and economic concerns of today's world dictate strict requirements for modern heavy duty engines, especially in emissions, noise control, power generation, and extended oil drain intervals. These requirements lead to increased stresses imposed on lubricants in modern heavy duty engines. At the same time, the original equipment manufacturers (OEMs) desire additional fuel economy from the lubricating oil, requiring the use of lower viscosity lubricants to minimize frictional losses in the engine. These lower viscosity oils are subjected to increased stresses in the engine and need to provide robust performance throughout their lifetime in order to protect engine parts from wear and damage. One of the most important lubricant qualities is to maintain viscosity throughout the drain interval and thus provide continuous engine protection.
2014-10-13
Technical Paper
2014-01-2797
Vicente Macian, Bernardo Tormos, Santiago Ruiz, Guillermo Miró, Tomás Pérez
Abstract Due to the increasingly stringent emissions standards in the world and, on the other hand, the foreseen shortage of fossil fuels, the application of low viscosity engine oils (LVO) is considered one of the most interesting options for counter these threats. In parallel to a fuel consumption fleet test, the aim of this study was to assess the performance of commercial low viscosity oils regarding their degradation and engine wear, since the use of LVO could imply an increase in wear rate. Potential higher engine wear could result in a reduction in the expected engine life cycle, obviously is a non-desired effect. In addition, currently limited data are available regarding “real-world” performance of LVO in a real service fleet.
2014-10-13
Technical Paper
2014-01-2779
Sunthorn Predapitakkun, Padol Sukajit
Abstract Engine lubrication in the global automotive industry has many challenges in the world today. One of them is the pursuit of fuel economy which has resulted in the growing popularity of lower viscosity engine oils. However, engine wear protection of low viscosity oils is not as robust as for higher viscosity grade oils. Due to this, low viscosity grade engine oils, such as SAE 0W-20, are not common in tropical climates, though they could provide the added benefit for fuel economy. To address these two seemingly discordant performance characteristics, PTT has developed a new API SN, SAE 0W-20 engine oil with a novel viscosity modifier and conducted a field trial with extended oil drain intervals to gain a better understanding of its performance in tropical climates, especially its wear protection performance in passenger cars.
2014-10-13
Technical Paper
2014-01-2792
Wim van Dam, James Booth, Gary Parsons
Advancement in Heavy Duty Diesel Engine Oils has, for approximately two decades, been driven by the ever more stringent emission legislation for NOx and Particulates. Over the last few years, the focus has shifted to reducing CO2 emissions, which created an interest in fuel efficient lubricants. In addition, increased fuel cost and a need to control operational expenses in a weaker economy have further heightened the interest in fuel efficient lubricants. Where the trucking industry was reluctant to move away from the tried and true SAE 15W-40 viscosity grade, there is now a strong interest in pushing the boundaries of lower viscosity to reduce internal friction in the engine and thereby improve fuel efficiency. Consequently, the industry is exploring and introducing lower viscosity grades, such as SAE 10W-30 and even SAE 5W-30.
2014-10-13
Technical Paper
2014-01-2794
Vicente Macian, Bernardo Tormos, Santiago Ruiz, Leonardo Ramirez Roa, Javier de Diego
Abstract This paper shows the results of a fuel consumption in-use comparison test where the effect of Low Viscosity Oils (LVO) was evaluated over a sample of 39 urban buses powered by Diesel and CNG engines. The aim of the test was to verify the fuel consumption benefits of LVO in Heavy Duty Vehicles (HDV) found in previous works, which were obtained mainly in engine test bench, when engines are working on “on-Road” conditions. In order to achieve this goal, a sample of 39 urban buses was studied over an Oil Drain Interval or 30.000 km (approximately an 11 month period), measuring daily mileage and fuel consumed to calculate each bus fuel consumption. Mileage was measured by GPS and fuel consumed was measured from refueling system. The sample was divided into two groups; a control group of buses using reference oils (SAE grade viscosities of 15W-40 and 10W-40) and a candidate group using LVO oils (SAE grade viscosities 5W-30).
2014-09-30
Technical Paper
2014-36-0200
Arthur L. Mainardi, Régis S. Kato
Abstract Internal combustion engines have been studied to obtain better efficiency in fuel consumption and hence lower emissions of greenhouse gases. The ideal would be to achieve these goals without sacrificing performance related to the torque and power, and specially without raising the production's cost. In this context, lubricating oil and lubrication system are very important as it has a major function in reducing engine friction. This paper presents an evaluation of the influence of different lubricating oil viscosities in cold engine friction, analyzing their effects on oil temperature, coolant, fuel consumption and starter motor speed. It also proposes a method for modeling the cold friction torque with the aid of the engine control module (ECM) idle speed control algorithm, aiming calibration time and cost reduction.
2014-09-30
Technical Paper
2014-36-0507
Margareth Carvalho, Katherine Richard, Isabella Goldmints, Eduardo Tomanik
Abstract Many countries are introducing fuel economy regulations in order to reduce the average emissions of light duty vehicles, since fuel consumption of vehicles is an important factor in air pollution. The lubricant has a significant role in reducing friction losses hence the fuel consumption, but the impact depends on the engine operation regime and the manner in which the lubricant components work together to change frictional properties. Different driving cycles are used by different countries and organizations to measure fuel consumption. The most common driving cycles are the European NEDC and the North American FTP-75 vehicle transient cycles. Fuel economy at full load and BSFC (Brake Specific Fuel consumption) are also common methods of measuring engine fuel economy.
2014-04-01
Technical Paper
2014-01-1483
Carrie B. Sims, Maryam Sepehr, Mark Sztenderowicz, Alexander Boffa
Abstract The ability of oil to retain its viscometric properties is particularly important in Heavy Duty Engine Oil applications to prevent wear and maintain intended levels of oil pressure. It is known that mechanical shearing of the oil, fuel dilution, oil oxidation and soot level all affect the aged oil kinematic viscosity at 100°C (KV100). For API CJ-4, as well as for many OEMs, an oil's KV100 must stay within the original viscosity grade as defined by SAE J300 after 90 cycles in the Kurt-Orbahn (KO) apparatus. This study investigates the effect of polymer chemistry and structure on extended shear stability of lubricating oils by evaluating the performance of two Viscosity Index Improver (VII) chemistries, Olefin Copolymer (OCP) and Hydrogenated Styrene Isoprene (HSI), under more severe shearing conditions than required for CJ-4. These technologies were evaluated in the KO shear test up to 700 cycles and the KRL shear test up to 8 hours.
2014-04-01
Technical Paper
2014-01-1658
Michael J. Plumley, Victor Wong, Mark Molewyk, Soo-Youl Park
Abstract Lubricant viscosity along the engine cylinder liner varies by an order of magnitude due to local temperature variation and vaporization effects. Tremendous potential exists for fuel economy improvement by optimizing local viscosity variations for specific operating conditions. Methods for analytical estimation of friction and wear in the power-cylinder system are reviewed and used to quantify opportunities for improving mechanical efficiency and fuel economy through lubricant formulation tailored specifically to liner temperature distributions. Temperature dependent variations in kinematic viscosity, density, shear thinning, and lubricant composition are investigated. Models incorporating the modified Reynolds equation were used to estimate friction and wear under the top ring and piston skirt of a typical 11.0 liter diesel engine.
2014-04-01
Journal Article
2014-01-1731
Kenji Matsumoto, Yuki Ono, Yoichi Kojima
In order to maintain the performance of push belt Continuously Variable Transmissions (CVT) over a long period of time, it is important to acquire a fundamental understanding of lubrication performance between a pulley and a metal V-belt. This work examined oil film thickness using the contact pressure on a sliding surface of pulley sheave during driving, which was obtained with an uniquely developed measurement technique. The contact between a belt element and a pulley sheave was treated as a group of small elliptical contact zones. The pressure-viscosity characteristics of lubricant were assigned to Reynolds equation with Roelands experimental formula. Also, in order to increase convergence of the calculation, a multigrid method was used. Calculation results indicate that the oil film thickness at a peak contact pressure measured was approximately 0.3-0.4 μm.
2013-10-14
Technical Paper
2013-01-2565
Jen Lung Wang
Control of oil viscosity increase at low temperature, which derives from the wax crystallization behaviors of various formulation components, is a critical performance criterion in modern engine oil lubricants. Failure to manage viscosity increase will result in high oil viscosity and poor oil pumpability under cold start conditions, and eventually may lead to catastrophic damage to the engine. The importance of oil low temperature rheology gained further attention when the ILSAC GF-4 specification implemented an aged oil low temperature viscosity limit to guarantee performance retention during operation. This requirement continues in ILSAC GF-5 and is regarded as one of the key benchmarks of modern passenger car engine oils. Pour point depressants (PPDs) are polymeric additives that help alleviate viscosity increase under tcold climate conditions through interaction and control of wax crystallization growth.
2013-10-14
Technical Paper
2013-01-2566
Massimo Manni, Salvatore Florio
Low and ultra low viscosity oils are one of the main solutions considered in view of the improvement of energy efficiency for better fuel economy. The recent modification of SAE J300 engine oil viscosity classification, to include engine oils with high temperature & high shear rate (HTHS) viscosity of 2.3 mPa·s for the SAE 16 grade, has opened debate on the possible real benefits that could derive, in terms of fuel economy and CO2 emission reduction, from the use of ultra low viscosity oils on engines of current technology. Two European compact cars (C-segment) of recent technology and similar characteristics were employed in our laboratories, on chassis-dyno test bed, to evaluate fuel economy with the use of oils having an HTHS viscosity decreasing from 2.9 to 2.0 mPa·s, with a −0.3 mPa·s step.
2013-10-14
Technical Paper
2013-01-2606
Nobuo Ushioda, Trevor W. Miller, Carrie B. Sims, Gary Parsons, Mark Sztenderowicz
The fuel economy performance of passenger car vehicles has been an area of keen focus due to recent environmental regulations. Various efforts such as the development of new engine technologies have been undertaken to improve the fuel economy performance of these vehicles. Engine oils have also been targeted to contribute to better fuel efficiency. This has been done by introducing new lubricant additive technologies and low viscosity grade oils. In the latter case, passenger car motor oils are about to enter into a new generation in which the lower viscosity grade SAE 16 has been approved and discussion has started on the specification of viscosity grades lower than SAE 16, although SAE 0W-20 viscosity grade is the lowest in the SAE J300 specification during last decade. Nevertheless, additive technology is also important, as we previously reported that simple reduction of viscosity grade is not a solution to improve fuel economy performance in the Sequence VID test.
2013-10-07
Technical Paper
2013-36-0155
Francisco J. Profito, Eduardo Tomanik, Luiz Fernando Lastres, Demetrio C. Zachariadis
Five automotive oils, with different viscosity grades, were tested under different loads and speeds in a reciprocating test using piston rings and cylinder liners. Starved and fully-flooded conditions were also considered in order to analyze the influence of lubricant supplier in the lubrication regimes, especially in boundary-mixed transition. The expected Stribeck curve behavior was observed, and more interesting visualization appeared when the viscosity value was extracted from the Stribeck abscissa axis. The higher viscosity oils showed lower friction coefficient at low speed/load ratios. Such behavior is usually neglected and may be significant to understand the triblogical behaviour of engineering components. Computer simulation showed similar results, including the “cross-over” speed/load when the lower viscosity oils start to show lower friction.
2013-04-08
Journal Article
2013-01-0299
William Barton, Daniel Jason Knapton, Mark Baker, Andrew Rose, Elizabeth A. Schiferl, Michael Huston, Gareth Brown, Gregory Hunt
This paper outlines the second part in a series on the effect of polymeric additives commonly known as viscosity modifiers (VM) or viscosity index improvers (VII) on gear oil efficiency and durability. The main role of the VM is to improve cold temperature lubrication and reduce the rate of viscosity reduction as the gear oil warms to operating temperature. However, in addition to improved operating efficiency across a broad temperature range compared to monograde fluids the VM can impart a number of other significant rheological improvements to the fluid [1]. This paper expands on the first paper in the series [2], covering further aspects in fluid efficiency, the effect of VM chemistry on these and their relationship to differences in hypoid and spur gear rig efficiency testing. Numerous VM chemistry types are available and the VM chemistry and shear stability is key to fluid efficiency and durability.
2011-10-06
Technical Paper
2011-28-0052
D. Singh, J. D. Fieldhouse, A. K. Jain, M. R. Tyagi, S. K. Singal
Engine components are exposed to various lubrication regimes such as hydrodynamic, elasto-hydrodynamic, boundary and mixed lubrication during engine operation. In each of these regimes, the factors which influence engine friction are different. Hydrodynamic friction is influenced by lubricant rheology, film thickness and sliding speed of interacting surfaces, whereas boundary and elasto-hydrodynamic friction is a function of surface properties like roughness and hardness and the type of friction modifier used in engine lubricant. So the principal factors which influence engine friction power are speed, load, surface topography of engine components, oil viscosity, oil temperature and type of friction modifiers used. Experimental studies on an off-highway diesel engine were conducted to investigate the effect of engine oil viscosity and engine operating conditions on engine friction power.
2011-08-30
Technical Paper
2011-01-2123
Torsten Stoehr, Boris Eisenberg, Ellen Suchert, Hugh Spikes, Jingyun Fan
Fuel economy has become the dominant criterion in the design of new automobiles. The globally enacted targets for fleet average emissions pose true challenges to automobile manufacturers. Increasing fuel economy requires enhancements both in hardware as well as in lubricant performance. As a key component of the lubricant, poly(alkyl methacrylate) PAMA viscosity index improvers have been identified as crucial design element due to their multiple modes of action. In their original application, they serve the well-known mechanism of polymer coil expansion at high temperatures and collapse at low temperatures. They help to flatten the viscosity/temperature relationship of the lubricant and allow for reduced low temperature viscosities and reduced internal friction, which directly translates into fuel economy. In addition to this bulk application, interfacial tribological phenomena contribute significantly to efficiency and fuel economy.
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