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This review paper summarizes major developments in vehicular emissions regulations and technologies (light-duty, heavy-duty, gasoline, diesel) in 2012. First, the paper covers the key regulatory developments in the field, including finalized criteria pollutant tightening in California; and in Europe, the development of real-world driving emissions (RDE) standards. The US finalized LD (light-duty) greenhouse gas (GHG) regulation for 2017-25. The paper then gives a brief, high-level overview of key developments in LD and HD engine technology, covering both gasoline and diesel. Marked improvements in engine efficiency are summarized for gasoline and diesel engines to meet both the emerging NOx and GHG regulations. HD engines are just starting to demonstrate 50% brake thermal efficiency. NOx control technologies are then summarized, including SCR (selective catalytic reduction) with ammonia, and hydrocarbon-based approaches.

Carefully controlled intake valve deposit (IVD) cleanup testing is found to be an effective method for differentiating the effect of the deposit control additives on combustion chamber deposits (CCD). The IVD buildup procedure produces a consistent initial level of CCD that the cleanup additive, the additive of interest, continues to build on until the end of the cleanup test. This “end of cleanup” CCD is found to be as repeatable and differentiable a measurement as tests run under the more common “keep clean” type operation. While IVD cleanup testing induces a mid-test disturbance in the form of the end of buildup measurement, it aligns well with two key CCD protocols in terms of the higher additive treat rates used and the extended total test length. In an analysis of results from IVD cleanup tests run using four different engine/vehicle procedures on seven different additives, several findings stood out.

The operating conditions of a typical motorcycle are considerably different than those of a typical passenger car and thus require an oil capable of handling the unique demands. One primary difference, wet clutch lubrication, is already addressed by the current JASO four-stroke motorcycle engine oil specification (JASO T 903:2011). Another challenge for the oil is gear box lubrication, which may be addressed in part with the addition of a gear protection test in a future revision to the JASO specification. A third major difference between a motorcycle oil and passenger car oil is the more severe conditions an oil is subjected to within a motorcycle engine, due to higher temperatures, engine speeds and power densities. Scooters, utilizing a transmission not lubricated by the crankcase oil, also place higher demands on an engine oil, once again due to higher temperatures, engine speeds and power densities.

One of the key functions of lubricating oil additives in diesel engines is to control oil thickening caused by soot accumulation. Over the last several years, it has become apparent that the composition of the base oil used within the lubricant plays an extremely important role in the oil thickening phenomenon. In particular, oil thickening observed in the Mack T-8 test is significantly affected by the aromatic content of the base oil. We have found that the Mack T-8 thickening phenomenon is associated with high electrical activity, i.e., engine drain oils which exhibit high levels of viscosity increase show significantly higher conductivities. These findings suggest that electrical interactions are involved in soot-induced oil thickening.

In this paper, we report the modeling of the selective catalytic reduction (SCR) of NOx using ammonia on a commercial vanadia-titania based catalyst. The model combines a steady-state two-dimensional channel model with a transient two- or three-dimensional monolith model of the whole catalytic monolith converter. The reaction mechanism includes the standard and fast SCR reactions and also the high-temperature oxidation of ammonia to model the decrease in conversion observed at higher temperatures. We used in-house experimental data spanning a wide range of inlet compositions and temperatures to validate the model. The model was found to be in excellent quantitative agreement with the experimental data.

Life Cycle Assessment (LCA) is a methodology used to determine quantitatively the environmental impacts of a range of options. The environmental community has used LCA to study all of the impacts of a product over its life cycle. This analysis can help to prevent instances where a greater degree of environmental harm results when changes are made to products based on consideration of impacts in only part of the life cycle. This study applies the methodology to engine lubricants, and in particular chlorine limits in engine lubricant specifications. Concern that chlorine in lubricants might contribute to emissions from vehicle exhausts of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), collectively called PCDD/F, led to the introduction of chlorine limits in lubricant specifications. No direct evidence was available linking chlorine in lubricants to PCDD/F formation, but precautionary principles were used to set lubricant chlorine limits.

Historically, vehicle fluid condition has been monitored by measuring miles driven or hours operated. Many current vehicles have more sophisticated monitoring methods that use additional variables such as fuel consumption, engine temperature and engine revolutions to predict fluid condition. None of these monitoring means, however, actually measures a fluid property to determine condition, and that is about to change. New sensors and diagnostic systems are being developed that allow real time measurement of some lubricant physical and/or chemical properties and interpret the results in order to recommend oil change intervals and maximize performance. Many of these new sensors use electrochemical or acoustic wave technologies. This paper examines the use of these two technologies to determine engine oil condition and focuses on the effects of lubricant chemistry on interpreting the results.

The Nissan KA24E engine test is designated to replace the Ford Sequence VE engine test as the low temperature valve train wear requirement for ILSAC (International Lubricant Standardization and Approval Committee) GF-3. The KA24E (recently designated the Sequence IV A) represents much of the current world-wide material and design technology while retaining the sliding cam/follower contact found in earlier engine designs. The work presented here is the first of two reports. In this first report, the physical and chemical environment the KA24E engine presents a lubricant is characterized and compared to those of the Sequence VE engine. Valve train materials and wear modes are investigated and described. Although chemical analysis of drain oils indicate the KA24E procedure does not degrade the lubricant to the extent seen in the Sequence VE test, valve train wear appears to proceed in a similar manner in both tests.

With the continued growth of the sport utility vehicle (SUV) market in North America in recent years more emphasis has been placed on fluid performance in these vehicles. In addition to fuel economy the key performance area sought by original equipment manufacturers (OEMs) in general has been temperature reduction in the axle. This is being driven by warranty claims that show that one of the causes of axle failure in these type vehicles is related to overheating. The overheating is, in turn, caused by high load situations, e.g., pulling a large trailer at or near the maximum rated load limit for the vehicle, especially when the vehicle or its main subcomponents are relatively new. The excessive temperature generally leads to premature failure of seals, bearings and gears. The choice of lubricant can have a significant effect on the peak and stabilized operating temperature under these extreme conditions.

It has been recognized for many years that multipurpose axle lubricants give rise to much higher axle break-in temperatures than lead-soap, active-sulfur or sulfur-chlorine-lead lubricants. Evaluation of differences in axle lubricant break-in temperature between the various multipurpose gear lubricants has been complicated by lack of repeatability and reproducibility. The work described in this paper shows that one of the most important variables affecting axle break-in temperature, under the conditions of the test technique used, was torsional axle preload and that control of dimensional preload in itself is not sufficient to ensure good test repeatability. The test technique described here has been used to evaluate the axle lubricant break-in temperature properties of several sulfur-phosphorus multipurpose gear lubricants.

Consumer demand for size, weight and horsepower has dictated a prominent role for sport utility vehicles and light trucks in the product lines of major North American automobile manufacturers. Inherently less efficient than passenger cars, these vehicles will be facing more stringent light duty CAFE (Corporate Average Fuel Economy) standards beginning in 2005 when mileage targets will be elevated to 21 mpg; this figure will be further increased to 22.2 mpg by 2007. In order to accommodate both public demand and CAFE requirements, vehicle manufacturers are seeking ways to improve fuel economy through design and material modifications as well as through improvements in lubrication. The axle lubricant may have an important impact on fuel economy, and axle lubricants can be tailored to deliver higher levels of operating efficiency over a wide range of conditions.

This paper outlines the history and background of the NLGI (formerly known as the National Lubricating Grease Institute) lubricating grease specifications, GC-LB classification of Automotive Service Greases as well as details on the development of new requirements for their High-Performance Multiuse (HPM) grease certification program. The performance of commercial lubricating grease formulations through NLGI's Certification Mark using the GC-LB Classification system and the recently introduced HPM grease certification program will be discussed. These certification programs have provided an internationally recognized specification for lubricating grease and automotive manufacturers, users and consumers since 1989. Although originally conceived as a specification for greases for the re-lubrication of automotive chassis and wheel bearings, GC-LB is today recognized as a mark of quality for a variety of different applications.

Sub-23nm particles emission from the light-duty vehicle is widely discussed now and possible to be counted into the next stage emission legislation, such as Euro7. In this article, 16 China6 gasoline vehicles were tested over the WLTC and two surrogate RDE lab cycles for particulate number (PN) emission, the difference between PN23 (particle size >23nm) and PN10 (particle size>10nm) emission was analyzed. Testing results showed that the average PN10 emission increased 59% compared to PN23, which will bring great challenges for those vehicles to meet the future regulation requirement if sub-23nm particle is counted. The sub-23nm particles emission was proportional to the PN23 particles emission and generated mostly from the cold start or the transient engine conditions with rich combustion. Compared to the proposal of Euro 7, PN10 emission from some tested vehicles will need further two orders of magnitude reduction.

SAE 2004-01-3009 reported on work conducted to investigate the correlation between the Mack T-11 laboratory engine tests and vehicle field tests. It concluded that the T-11 test provides an effective screening tool to investigate soot-related viscosity increase, and the severity of the engine test limits provides a substantial margin of safety compared to the field. This follow-up paper continues the studies on the 2003 Mack CV713 granite dump truck equipped with an AI-427 internal EGR engine and introduces experimentation on a 2003 CX613 tractor unit equipped with an AC-460P cooled EGR engine. The paper further assesses the correlation of the field trials to the Mack T-11 engine test and reviews the impact of ultra low sulfur diesel (ULSD) and prototype CJ-4 lubricant formulations in these engines.

Recently, SiC has been investigated and pursued as an alternative material for diesel particulate filter (DPF) applications. SiC has acceptable physical properties such as good thermal conductivity, refractoriness, and chemical durability. Materials for DPF applications require a particular mean pore size, porosity, and permeability. In addition, these material attributes must be coupled to an appropriate thermal design so that the filter can survive the extreme temperature gradients generated during the regeneration process. In this report several approaches to making porous SiC will be discussed and performance data based on material properties and thermal design will be presented.

Diesel particulate filters are expected to be used on most passenger car applications designed to meet coming European emission standards, EU5 and EU6. Similar expectations hold for systems designed to meet US Tier 2 Bin 5 standards. Among the various products oxide filter materials, such as cordierite and aluminum titanate, are gaining growing interest due to their unique properties. Besides the intrinsic robustness of the filter products a well designed operating strategy is required for the successful use of filters. The operating strategy is comprised of two elements: the soot estimation and the regeneration strategy. In this paper the second element is discussed in detail by means of theoretical considerations as well as dedicated engine bench experiments. The impact the key operating variables, soot load, exhaust mass flow, oxygen content and temperature, have on the conditions inside the filter are discussed.

Direct injection spark ignition (DISI) engine technology offers tremendous potential advantages in fuel savings and is likely to command a progressively increasing share of the European passenger vehicle market in the future. A concern is its propensity to form deposits on the inlet valve. In extreme cases, these deposits can lead to poor drivability and deteriorating emission performance. This inlet valve deposit build up is a well-known phenomenon in DISI engines since even additised fuel cannot wash over the back of intake valves to keep them clean. Two lubricants and two fuels were tested in a four car matrix. One of the lubricants was a fluid specifically developed by Lubrizol for DISI technology; the other was a baseline oil meeting Ford lubricants requirements and was qualified to ACEA A1/B1/ ILSAC GF2 performance level. Similarly, a baseline fuel was tested against an additised system.

The diesel oxidation catalyst is required to remove hydrocarbons and carbon monoxide from the diesel engine exhaust stream while minimizing the impact of all other features such as cost, space, pressure drop, weight, fuel consumption, etc. The challenge of designing a catalytic converter for a particular application then becomes to: first, understand the emissions and other performance targets and requirements for the engine; second, understand the influence each of the converter parameters has on the overall system performance and; third, optimize the system using these relationships. This paper will explore some of the considerations with respect to the second of the above challenges.

Information on transport mechanisms in a Diesel Particulate Filter (DPF) provides crucial insight into the filter performance. Extensive experimental work has been pursued to modify, customize and validate a model yielding accurate predictions of a ceramic wall-flow DPF pressure drop. The model accounts, not only for the major pressure drop components due to flow through porous walls but also, for viscous losses due to channel plugs, flow contraction and expansion due to flow entering and exiting the trap and also for flow secondary inertial effects near the porous walls. Experimental data were collected on a matrix of filters covering change in filter diameter and length, cell density and wall thickness and for a wide range of flow rates. The model yields accurate predictions of DPF pressure drop with no particulate loading and, with adequate adjustment, it is also capable of making predictions of pressure drop for filters lightly-loaded with particulates.

Over the past decade, regulations for mobile source emissions have become more stringent thus, requiring advances in emissions systems to comply with the new standards. For the popular diesel powered passenger cars particularly in Europe, diesel particulate filters (DPFs) have been integrated to control particulate matter (PM) emissions. Corning Incorporated has developed a new proprietary aluminum titanate-based material for filter use in passenger car diesel applications. Aluminum titanate (hereafter referred to as AT) filters were launched commercially in the fall of 2005 and have been equipped on more than several hundred thousand European passenger vehicles. Due to their outstanding durability, filtration efficiency and pressure drop attributes, AT filters are an excellent fit for demanding applications in passenger cars. Extensive testing was conducted on engine to evaluate the survivability and long-term thermo-mechanical durability of AT filters.