SoCalGas, California agencies funding $9M RFP to develop ultra-low NOx heavy-duty natural gas engines

Southern California Gas Co. (SoCalGas), the South Coast Air Quality Management District (SCAQMD), the San Joaquin Valley Air Pollution Control District (SJVAPCD) and the California Energy Commission (CEC) are jointly funding a request for proposals (RFP) (P2013-22) issued by SCAQMD to support the development of ultra-clean natural gas engines for a variety of heavy-duty vehicle applications in the South Coast Air Basin (SCAB) and San Joaquin Valley Air Basin (SJVAB).

The initiative, funded up to $9 million by the participating agencies together with $500,000 in matching funds from SoCalGas, aims to demonstrate natural gas engines capable of achieving aggressive, near-zero emission standards for on-road, heavy-duty vehicle applications suitable for refuse, goods movement, drayage, transit, or school bus applications.

The purpose of the RFP is to provide financial assistance to contractor teams to develop near-zero NO_x heavy-duty natural gas engines; integrate the engines into heavy-duty vehicles chassis; and evaluate the performance of the vehicles in a variety of heavy-duty vehicle applications in the South Coast and San Joaquin Valley Air Basins.

The principal RFP emission target is 0.02 grams per brake horsepower-hr (g/bhp-hr) NO_x; this represents a 90% reduction from the current EPA 2010 standard of 0.2 g/bhp-hr NO_x. Other targets are 0.01 g/bhp-hr particulate matter (PM); 0.14 g/bhp-hr hydrocarbon (HC); and 15.5 g/bhp-hr carbon monoxide (CO) or lower as determined by the heavy-duty engine Federal Test Procedure (FTP)-comparable to the EPA 2010 limits.

Proposals that address methods to achieve 10 ppm or lower NH₃ emission will score higher, and similarly those that address methods to achieve minimal or zero fuel economy penalties when compared to similar 2010 certified diesel engines, will score higher.

To reach the low NO_x emission target and keep the PM, HC, and CO at current or lower emissions levels, proponents may propose all or combinations of:

• optimized combustion chamber technology;
• advanced fuel delivery system;
• air handling system;
• advanced electronic controls; and
• exhaust after-treatment technologies.

Proponents will be required to build prototype heavy-duty natural gas engines and exhaust after-treatment technology, and to perform transient engine dynamometer tests of the prototype engines to assess fuel consumption, gaseous emissions, and particulate matter emissions.

Production-intent or production engines with exhaust after-treatment technology will then be built based on the prototype engines and integrated into an on-road heavy-duty prototype vehicle chassis suitable for refuse, goods movement, drayage truck, transit, or school bus applications and further developed to ensure adequate transient performance and drivability.

At least three production-intent or production vehicles will then be deployed and demonstrated in commercial services to evaluate performance, reliability, and emissions expectations. A heavy-duty chassis dynamometer will be needed for prototype vehicle development and in-use emissions testing.

Proposals are due by 24 July 2013.

http://www.greencarcongress.com/2013/06/gas-20130613.htm

Consumer Reports testing finds many small turbo engines underperforming; fuel economy, acceleration no better than in larger conventional powertrains

Consumer Reports' own fuel economy tests of vehicles equipped with small turbocharged engines has found in many cases that the turbocharged cars tested by CR have slower acceleration and no better fuel economy than the models with larger conventional engines, the organization said.

Consumer Reports tests many cars with small, turbocharged engines, and many competitors with traditional, naturally aspirated engines, large and small. Based on the EPA fuel-economy estimates, many of the charged engines look better. However, CR testers found those results don't always map to real world driving and Consumer Reports' own fuel economy tests.

As another example, in December, Consumer Reports road testing found the fuel economy on the 2013 Fusion Hybrid sedan and new C-Max Hybrid falling far short below Ford (and EPA) triple 47 mpg (5.0 l/100 km) figures-i.e., 47 mpg for city, highway and combined-for both vehicles. (Earlier post.)

While these engines may look better on paper with impressive EPA numbers, in reality they are often slower and less fuel efficient than larger four and six-cylinder engines.

-Jake Fisher, director of automotive testing for Consumer Reports

Consumer Reports points to the collection of 2013 Ford Fusions with EcoBoost engines as the latest example of underperforming small turbocharged engines. The smaller engine-a 1.6-liter producing 173 hp-is a $795 option over the basic conventional 2.5-liter Four on Fusion SE models. But that car's 0-60 mph acceleration time trails competitive family sedans, and it delivers just 25 mpg, placing it among the worst of the crop of recently-redesigned family sedans, according to CR.

The most direct comparison among the vehicles Consumer Reports has tested is the Chevrolet Cruze. CR tested both a Cruze with the base 1.8-liter conventional four-cylinder, and one with the smaller 1.4-liter turbocharged four. While the 1.4-liter feels marginally more powerful in daily driving, it was barely faster to 60 mph, and got the same fuel economy as the larger engine, CR said.

The Hyundai Sonata Turbo, Kia Sportage Turbo, and Ford Escape 2.0T are examples of cars with turbocharged four-cylinder engines that are less fuel efficient than V6 models in the same class, Consumer Reports found.

Consumer Reports has also found some turbocharged four-cylinder models that do deliver good fuel economy and acceleration: BMW's new 2.0-liter turbocharged four gets 28 mpg in the new 328i Sedan and delivered improved mileage in the 2012 X3 SUV by one mpg, with essentially identical power and acceleration.

Volkswagens using that company's 2.0-liter turbo also return what CR calls "impressive mileage", though CR hasn't tested any model variations with other engines that are directly comparable.

In contrast, BMW's turbocharged four-cylinder engines seem to deliver both good fuel economy and acceleration: The 2.0-liter turbocharged four cylinder contributes to 28 mpg overall in our last tested 328i sedan. It improved mileage only marginally in the 2013 X3 SUV compared to the six-cylinder 2011 X3 we tested, with essentially identical power and acceleration but somewhat comprised refinement. The 2.0-liter turbo four cylinder engine we've tested in Audis and Volkswagens usually return impressive mileage, though we haven't tested any identical model powered by two different engines for such a direct comparison.

Consumer Reports testing results (turbos in bold)
Model	Engine	0-60 mph	EPA mpg	CR mpg
Ford Fusion	1.6L Turbo 4	8.9	28	25
Hyundai Sonata	2.4L Four	8.2	26	27
Kia Optima	2.4L Four	8.6	27	25
Toyota Camry	2.4L Four	8.4	28	27
Honda Accord	2.4L Four	7.7	30	30
Nissan Altima	2.4L Four	8.2	27	31
Ford Fusion	2.0L Turbo 4	7.4	26	22
Hyundai Sonata	2.0L Turbo 4	6.6	26	25
Kia Optima	2.0L Turbo 4	6.6	26	24
Toyota Camry	3.5L V6	6.4	25	26
Honda Accord	3.5L V6	6.3	25	26
Nissan Altima	3.5L V6	6.3	23	24
Chevrolet Cruze	1.4L Turbo 4	9.8	28	26
Chevrolet Cruze	1.8L Four	10.5	27	26
Dodge Dart	1.4L Turbo 4	8.6	31	29
Dodge Dart	2.0L Four	11.0	27	27
Ford Escape	1.6L Turbo 4	9.9	25	22
Honda CR-V	2.4L Four	9.2	25	23
Kia Sportage	2.4L Four	10.3	23	22
Toyota RAV4	2.5L Four (2012)	10.0	24	23
Ford Escape	2.0L Turbo 4	8.2	24	22
Kia Sportage	2.0L Turbo 4	7.1	22	21
Toyota RAV4	3.5L V6 (2012)	6.7	22	22
BMW X3	2.0L Turbo 4	7.3	24	23
BMW X3	3.0L Six	7.2	21	22
Ford F-150	3.5 V6 Turbo	7.7	17	15
Ford F-150	5.0L V8	7.8	16	15

http://www.greencarcongress.com/2013/02/consumer-reports-testing-finds

ORNL researchers quantify the effect of increasing highway speed on fuel economy

John F. Thomas, Brian H. West and Shean P. Huff
Fuels, Engines and Emissions Research Center, Oak Ridge National Laboratory

Figure 1. Vehicle installed on the chassis dynamometer in the ORNL vehicle research laboratory. Click to enlarge.

Oak Ridge National Laboratory (ORNL) staff have been performing vehicle research and testing in support of the fueleconomy.gov website. This website, jointly maintained by the US Department of Energy and the US Environmental Protection Agency (EPA), provides information such as official EPA "window label" fuel economy estimates for city, highway, and combined driving for all U.S.-legal light-duty vehicles from 1984 to present. It also offers consumer information and advice pertaining to vehicle fuel economy and energy-related issues such as driving tips. One tip is that drivers should obey the speed limit since the fuel economy of most vehicles decreases above 50 mph [80 km/h].

ORNL staff members John Thomas, Shean Huff and Brian West have worked to quantify this trend through analysis of dynamometer testing results for 74 vehicles at steady-state speeds from 50 to 80 mph [80 to 129 km/h].

Data has been collected for 23 light-duty vehicles at ORNL's vehicle research laboratory and a valuable data set for 51 vehicles was loaned to ORNL by Chrysler, LLC under a non-disclosure agreement. Vehicles were tested in dynamometer laboratories at steady speeds from 40 to 80 mph [64 to 129 km/h], with the proper road-load applied. Analysis has focused on speeds of 50, 60, 70 and 80 mph.^[1] The data resulting from these tests simulates steady highway cruising on flat roads at moderate temperatures (SAE J2263, J2264).

The study includes various sizes of sedans, wagons, and SUVs, as well as pickup trucks, minivans and a few "muscle" and sports cars. Vehicles from model years 2003 to 2012 with a wide variety of powertrains were represented and included two hybrid sedans and a diesel sedan. The combined data from the 74 vehicles gives insight into the effect of cruising speed on fuel economy.

Results are quantified in the summary table, showing the general effect of increased speed on fuel economy. For example, the last column in the table for the row with 70 to 80 mph results reveals that most vehicles will have 12.5-17.5% drop in fuel economy due to traveling 80 mph rather than 70 mph. No obvious pattern for specific vehicle types in terms of fuel economy percent change with speed has yet emerged (for example, results for SUVs were similar to small sedans or pickup trucks in terms of percent change in mpg).

Brief summary of vehicle data
Speed increase	Percent mpg decrease for a given 10 mph increase based on 74 vehicles.
	Average	Data range	Std. deviation	Middle 2/3s of vehicle data
50 to 60 mph	12.4	6.9-18.3	2.2	10.0-14.3
60 to 70 mph	14.0	8.8-19.5	2.6	11.2-16.1
70 to 80 mph	15.4	10.8-26.0	3.0	12.5-17.5
All three speed increments	13.9	6.9-26.0	2.9	N/A

The results are summarized in histogram form in Figure 2, which shows the distribution of fuel economy penalties for each 10-mph increase in speed from 50 mph to 80 mph. A comparison of the three histograms shows a slight shift toward higher mpg penalties for each 10-mph speed increase. In other words, the mph penalty for increasing your speed from 70 mph to 80 mph is slightly greater than the penalty for increasing from 60 mph to 70 mph, which is slightly greater than the penalty for increasing from 50 mph to 60 mph.

Figure 2. The fuel economy penalty (for a 10-mph increase in speed) becomes more severe at higher speeds.[2] Click to enlarge.

The bottom histogram highlights some further interesting observations that were made from the data. There are explanations for four of the five vehicles represented in the "warm" colored bars showing the high fuel economy drop values (> 21%) for the 70 to 80 mph case.

Three V8 sedans with cylinder deactivation were included in the vehicle set, and were responsible for some of the largest values seen in the table and Figure 2. These vehicles conserve fuel by only powering 4 cylinders at lower speeds, and then switch to 8 cylinders when needed to meet the power demand at higher speeds. The switch from 4 to 8 cylinders was seen to occur between 60 and 70 mph or 70 and 80 mph, and this change causes a large percent change in fuel economy over that speed increment.

An ORNL tested vehicle was observed to transition from stoichiometric operation to protective enrichment between 75 and 80 mph, and this change caused an unusually steep drop in fuel economy. Protective enrichment occurs when a vehicle's engine is at a high load point such that the exhaust temperatures may become great enough to damage the catalyst or other components: damage is avoided by injecting extra fuel (rich fueling) which produces lower temperature exhaust. The Chrysler data included a vehicle that appears to employ protective enrichment at 80 mph. These two vehicles are responsible for the two highest fuel economy drops in the data set (~25 and 26% when comparing 70 to 80 mph).

Testing was not conducted beyond 80 mph, but it is reasonable to think more vehicles would transition into protective enrichment operation at speeds above 80 mph. This may be a valid consideration for setting maximum speed limits.

Footnotes

• ^[1] Road-loads are determined by on-road coastdown testing, and are simulated by the chassis dynamometer according to SAE Standards J2263, J2264.

• ^[2] 68 vehicles are represented in the histogram for traveling 80 mph versus 70 mph. The other 2 histograms contain data for 74 vehicles. Six vehicles were tested only to 70 mph.

Resources

• J.F. Thomas, H-L. Hwang, B. West, S. Huff, Predicting Light-Duty Vehicle Fuel Economy as a Function of Highway Speed, SAE technical paper 2013-01-1113, SAE 2013 World Congress, Detroit, MI, April, 2013 (in press)

http://www.greencarcongress.com/2013/01/thomas-20130117.htm