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Gasoline turbocharged direct injection (GTDI) engines, such as EcoBoost™ from Ford, are becoming established as a high value technology solution to improve passenger car and light truck fuel economy. Due to their high specific performance and excellent low-speed torque, improved fuel economy can be realized due to downsizing and downspeeding without sacrificing performance and driveability while meeting the most stringent future emissions standards with an inexpensive three-way catalyst. A logical and synergistic extension of the EcoBoost™ strategy is the use of E85 (approximately 85% ethanol and 15% gasoline) for knock mitigation. Direct injection of E85 is very effective in suppressing knock due to ethanol's high heat of vaporization - which increases the charge cooling benefit of direct injection - and inherently high octane rating. As a result, higher boost levels can be achieved while maintaining optimal combustion phasing giving high thermal efficiency.

Particulate emissions cause adverse health effects and for this reason they are regulated since the 80s. Vehicle regulations cover particulate emission measurements of a model before its sale, known as type approval or homologation. For heavy-duty engines the emissions are measured on an engine dynamometer with steady state points and transient cycles. For light-duty vehicles (i.e. the full power train) the particulate emissions are assessed on a chassis dynamometer. The measurement of particulate emissions is conducted either by diluting the whole exhaust in a dilution tunnel with constant volume sampling or by extracting a small proportional part of the exhaust gas and diluting it. Particulate emissions are measured by passing part of the diluted exhaust aerosol through a filter paper. The increase of the weight of the filter is used to calculate the particulate matter mass (PM) emissions.

As automakers strategize approaches to sustainable vehicle technologies, alternative powertrains must be considered to reduce future fleet vehicle emissions and improve energy security. These alternative vehicles include different fuels and electrification. The ultimate for on-road CO2 reductions is a zero emission vehicle, which can be achieved by either a hydrogen fuel cell or battery electric vehicle. These vehicles would also require a renewable energy source to provide their propulsion energy in order to achieve maximum sustainability for both CO2 reduction and energy security. Renewable energy sources such as wind or solar result in heat or electricity that needs to be generated into an energy carrier such as hydrogen or stored in a battery. When examining these options based strictly on the efficiency path, previous analysis have concluded fuel cell vehicles may not be an appropriate suitability strategy in comparison to battery electric vehicles.

Internal combustion (IC) engines fueled by hydrogen are among the most efficient means of converting chemical energy to mechanical work. The exhaust has near-zero carbon-based emissions, and the engines can be operated in a manner in which pollutants are minimal. In addition, in automotive applications, hydrogen engines have the potential for efficiencies higher than fuel cells.[1] In addition, hydrogen engines are likely to have a small increase in engine costs compared to conventionally fueled engines. However, there are challenges to using hydrogen in IC engines. In particular, efficient combustion of hydrogen in engines produces nitrogen oxides (NOx) that generally cannot be treated with conventional three-way catalysts. This work presents the results of experiments which consider changes in direct injection hydrogen engine design to improve engine performance, consisting primarily of engine efficiency and NOx emissions.

New emissions certification requirements for medium duty vehicles (MDV) meeting chassis dynamometer regulations in the 8,500 lb to 14,000 lb weight classes as well as heavy duty (HD) engine dynamometer certified applications in both the under 14,000 lb and over 14,000 lb weight classes employing large diameter exhaust pipes (up to 4″) have created new exhaust stream sampling concerns. Current On-Board-Diagnostic (OBD) dyno certified particulate matter (PM) requirements were/are 7x the standard for 2010-2012 applications with a planned phase in down to 3x the standard by 2017. Chassis certified applications undergo a similar reduction down to 1.75x the standard for 2017 model year (MY) applications. Failure detection of a Diesel Particulate Filter (DPF) at these low detection limits facilitates the need for a particulate matter sensor.

A model of Ford's current FTP based OBD-II catalyst monitor has been developed and used in determining the optimal monitored catalyst volume for several LEV applications. The model predictions were found to agree reasonably well with the available experimental data. Furthermore, the results of this study indicate that the optimal monitored catalyst volume for meeting LEV requirements is vehicle application specific. As a result, it is concluded that a general guideline for sizing of the monitored catalyst volume for LEVs will most likely be inadequate and could result in grossly suboptimal catalyst monitor function for some applications. The model which is described in this paper offers a potentially more effective means of determining the best monitored catalyst volume for a given vehicle application. It should be possible to utilize this model during the early phase of a vehicle program in order to provide for the optimal packaging of the catalyst monitor sensor (CMS).

The effect of fuel sulfur on the dual HEGO sensor OBD-II catalyst monitor has been investigated. Laboratory studies revealed two competing effects of the fuel sulfur on the operation of the catalyst monitor: 1. the loss of catalyst oxygen storage capacity, and 2. the degradation in the response rate of the rear HEGO sensor. The magnitude of the loss in catalyst OSC relative to the increase in rear HEGO sensor response time determined whether the rear HEGO sensor index increased, decreased, or remained constant as the fuel sulfur level was increased. The effect of fuel sulfur on tailpipe emissions and the catalyst monitor was also measured for two LEVs equipped with Pd-only catalyst technology (a 1997MY Escort and a 1998MY Crown Victoria). For both vehicles, the effect of the fuel sulfur on the rear HEGO sensor response characteristics dominated; as the fuel sulfur level was increased, tailpipe emissions increased, but the rear HEGO sensor index decreased.

Robust on-board diagnosis of emission catalyst performance requires the development of artificially damaged "threshold" catalysts that accurately mimic the performance of damaged catalysts in customer use. The threshold catalysts are used by emissions calibrators to determine fore-aft exhaust oxygen sensor responses that indicate catalyst failure. Rather than rely on traditional trial-and-error processes to generate threshold catalysts, we have used a DFSS (Design For Six-Sigma) approach that explores, at a research level, the relationship between oxygen storage capacity (OSC) of the catalyst (i.e., the fundamental property dictating the response of the aft oxygen sensor) and key process input variables: high-temperature exposure, phosphorus poisoning, and catalyst "recovery."

Exhaust gas temperature is often measured with a device such as thermocouple or RTD (Resistance Temperature Detector). An alternative method to determine the gas temperature would be to use an existing gas sensor heating mechanism to perform as a temperature sensor. A planar type FLOH (Fast Light Off HEGO-Heated Exhausted Gas Oxygen) sensor under transient vehicle speed/load conditions is suited to this function and was modeled to predict the exhaust gas temperature. The numerical input to the model includes exhaust flow rate, heater voltage, and heater current. Laboratory experiments have been performed to produce an equation relating the resistance of the heater and the temperature of the sensor (heater), which provides a method to indirectly determine HEGO sensor temperature.

The requirements to produce high specific power, a high torque across a broad engine speed range and very low emissions levels have been seen as mutually exclusive in a conventional normally aspirated SI engine. Ford Motor Co in association with Cosworth Technology Ltd. have developed a port injection SI engine which achieves in excess of 63kW/ltr, a peak torque in excess of 97Nm/ltr, 92Nm/ltr between 2500rpm and 6500rpm and meets European IV and North American LEV emissions levels for the Focus ST170 in Europe and the SVT Focus in the US. To achieve the required torque across the speed range the volumetric efficiency needed to be maximized at all engine speeds. This was done by fitting continuously variable inlet valve timing, variable length intake manifold and a tuned exhaust manifold. To meet the emissions requirements, the catalyst light off time must be kept to a minimum.

The Vehicle Exhaust Emissions Simulator was developed to evaluate the performance of vehicle emissions sampling and analytical systems. The simulator produces a representative tailpipe volume flow rate containing up to five emission constituents, injected via mass flow controllers (MFCs). Eliminating the variability of test results associated with the vehicle, driver, and dynamometer makes the simulator an ideal quality control tool for use in commissioning new test cells, checking data correlation between test cells, and evaluating overall system performance. Earlier vehicle emissions simulators being used in the industry were primarily for checking Constant Volume Samplers (CVSs) and Bag Benches but they did not have the ability to properly simulate tailpipe volume.

Partial flow sampling methods in emissions testing are interesting and preferred because of their lower cost, smaller size and applicability to engines of all sizes. However the agreement of the results obtained with instruments based on this method to those obtained with the traditional, large tunnel full flow sampling systems needs to be achieved, and the factors of construction that influence this agreement must be understood. These issues have received more attention lately in connection with ISO and WHDC standardization efforts underway to achieve a world-wide harmony in the sampling methods for heavy duty diesel engines, and with the introduction of similar Bag-minidiluter techniques into light duty SULEV gaseous pollutant measurement. This paper presents the theory and practice of a partial flow probe and tunnel design that addresses and minimizes the undesirable effects of the necessary differences between the two sampling methods.

The first known, North American OEM vehicle powered exclusively by a hydrogen fueled internal combustion engine (H2ICE) has been developed and tested. This production viable, low cost, low emission vehicle is viewed as a short term driver for the hydrogen fueling infrastructure ultimately required for fuel cell vehicles. This vehicle features a highly optimized hydrogen IC engine, a triple redundant hydrogen safety system, and a dedicated gaseous hydrogen fuel system. The vehicle and its test results are presented in this paper.

Particulate and manganese mass emissions have been measured as a function of mileage for four Escort and four Explorer vehicles using 1) MMT (Methylcyclopentadienyl Manganese Tricarbonyl) added to the gasoline at 1/32 g Mn/gal and 2) gasoline without MMT. The MMT was used in half of the fleet starting at 5,000 miles. The vehicles were driven on public roads at an average speed of 54 mph to accumulate mileage. This report describes the particulate and manganese emissions, plus emissions of four air toxics at 5,000, 20,000, 55,000, 85,000 and 105,000 miles. Four non-regulated emissions were measured and their average values for vehicles without MMT were 0.6 mg/mi for formaldehyde, 0.7 mg/mi for 1,3-butadiene, 9 mg/mi for benzene and 12 mg/mi for toluene. Corresponding values for MMT-fueled vehicles were between 1.5 and 2.4 times higher.

The combined requirement of achieving CAFE values between 32 to 38 mpg plus LEV/ULEV emission standards to comply with US legal requirements between 1995 and 2000 represents the most demanding challenge for engine engineering. Thus all possible methods of engine improvement towards fuel economy and emissions have to be considered. Besides using new ideas also the methods of engine development have to be modernized to cope with the challenge. The paper presents advanced combustion and exhaust gas aftertreatment systems which combine high power output, favourable torque characteristics and high fuel economy with the potential for obtaining LEV/ULEV emission values, as well as improved development techniques.

Emissions sample probes are widely used in engine and vehicle emissions development testing. Tailpipe bag summary data is used for certification, but the time-resolved (or modal) emissions data at various points along the exhaust system is extremely important in the emission control technology development process. Exhaust gas samples need to be collected at various locations along the exhaust aftertreatment system. Typically, a tube with a small diameter is inserted inside the exhaust pipe to avoid any significant effect on flow distribution. The emissions test equipment draws a gas sample from the exhaust stream at a constant volumetric flow rate (typically around 10 SLPM). The sample probe tube delivers exhaust gas from the exhaust pipe to emissions test equipment through multiple holes on the surface of tube. There can be multiple rows of holes at different axial planes along the length of the sample probe as well as multiple holes on a given axial plane of the sample probe.

Automotive three-way catalysts (TWC) were characterized using temperature-programmed reduction (TPR), x-ray diffraction (XRD), Raman spectroscopy, chemisorption measurements and laboratory activity measurements. Capabilities and limitations of these standard analytical techniques for the characterization of production-type automotive catalysts are pointed out. With the exception of chemisorption techniques, all appear to have general utility for analyzing exhaust catalysts. The techniques were used to show that the noble metals and ceria in fresh Pt/Rh and Pd/Rh catalysts are initially highly dispersed and contain a mixture of interacting and non-interacting species. Thermal aging of these catalysts (in the reactor or vehicle) caused both precious metal and ceria particles to sinter, thereby decreasing the interaction between the two.

Recent Federal and California legislation have mandated major improvements in emission control. Tailpipe HC emission must be decreased an order of magnitude for the California Ultra Low Emission Vehicle (ULEV) standard. Present feedback A/F* control systems employ a Heated Exhaust Gas Oxygen sensor (HEGO sensor) upstream of the catalyst to perform A/F feedback control. Limitations on the ultimate accuracy of these switching sensors are well known. To overcome these limitations a linear Universal Exhaust Gas Oxygen sensor (UEGO sensor) placed downstream from the minicatalyst is employed to attain improved A/F control and therefore, higher three-way catalyst (TWC) conversion efficiency. This configuration was granted a patent in 1992 (1**). This study compares performance differences between the two feedback control systems on a Ford Mustang. In initial studies both the UEGO and HEGO sensors were compared at the midposition location downstream of a minicatalyst.

Here we present a latent heat storage device which is used to provide “quick/supplemental” heat to the vehicle's conventional heating system. First, we present data from actual in-vehicle cold weather tests. Data are presented for heater and defroster performance tests, emissions tests and cold start tests after extended soaks. Secondly, heater performance predictions are made using a computer simulation program. Finally, the actual heater performance results are compared with the computer simulation.