Analysis Results
Emissions testing of2019 Ford F250 at Mustang Dynamometerusing the3DATX Inc. parSYNC® miniPEMS

May 16, 2019

Executive Summary
Mustang Dynamometer, a vehicle chassis-based dynamometer testing equipment manufacturer, measured
emissions from a model year 2019 Ford F250 at their Ohio facility using the 3DATX Inc. parSYNC
miniPEMS (portable emissions measurement system). For regulatory certification and compliance,
emissions measurement is conducted using 40 CFR 1065 certified PEMS. These systems often weighover a 100 lbs., are complicated to install, use, and maintain, and have high ownership cost. This simple
pilot test was conducted to see how the results from parSYNC miniPEMS, which is significantly smaller,lighter, easier to set up, and much lower cost of ownership would compare to official certification results.
The test was conducted over the FTP72 test cycle and the g/mile NOx rate are compared with theCalifornia Air Resources Board (CARB) certification for this vehicle. Note that the CARB certification isover the FTP75 test cycle which adds a hot start phase to the end of the FTP72 cycle. Other differences
between the pilot test reported here and the certification test would be that the certification requires
vehicle prep, specific fuel quality, and direct measurement of exhaust flow or accurate ECU data toestimate the same.
The NOx rates for the two repeats of the FTP72 are 0.23 g/mile and 0.20 g/mile. This compares very wellwith the CARB certification standard of 0.20 g/mile for this vehicle. It is expected that the FTP75 cycle
would lead to somewhat lower rates because the engine is warmed up. On the other hand, the exhaust
flow (in this pilot test) was based on the intake air flow and is expected to be biased low compared to amore comprehensive flow measurement. Putting those two together, it is expected that the results fromthe parSYNC system would come to be within 5% of a 1065 approved PEMS.

Test Vehicle
Date of Testing: April 16, 20192019 Ford F50 Pickup 4WD
Fuel: Diesel 7-15 ppm Sulfur
Vehicle class: MDV4, MDV 8501-10000 GVWR
Federal Exhaust Emission Standard: Tier 3 HD Class 2b Transitional Bin 340
California Emission Category: LEV2 ULEVEngine: 6.7 liter
Test Group: KFMXD06.761BUseful Life: 120,000 miles
Exhaust Emission Control Systems:
TC - turbo charger
DFI - direct fuel injection
CAC - charge air cooler
EGR - exhaust gas recirculation
OC - oxidizing catalyst
DPF - diesel particulate filter (active)
SCRC - selective catalytic reduction
NOXS (2) - NOx sensor
RDQS - reductant quality sensor

2019 Ford F250
NMHC (g/mi)
CO (g/mi)Certification Level
0.043
0.2
California FTP-75 standard 0.143
6.4
https://www.dieselnet.com/standards/us/ld_ca.php#levii

NOx (g/mi)
0.2
0.2

2019 Ford F250
NMHC + NOx (mg/mi) CO (g/mi)
EPA FTP-75 standard340
6.4
https://www.dieselnet.com/standards/us/ld_t3.php#hdv
FTP-75 cycle : https://www.dieselnet.com/standards/cycles/ftp75.php
Duration: 1877 seconds
Distance: 11.04 miles

HCHO (mg/mi)
6
16

HCHO (mg/mi)
6PM (g/mi)
0.01
0.06

PM (mg/mi)
8

Test Setup

Cycles Tested
FTP-72 (aka UDDS): https://www.dieselnet.com/standards/cycles/ftp72.php
US06 cycle (Supplemental FTP, SFTP): https://www.dieselnet.com/standards/cycles/ftp_us06.php
Note that the emissions standards are for FTP-75, while the test data is for FTP-72

Post-processing
Time-alignment: ECU data was synchronized with parSYNC data using Fuel Rail Pressure and CO2 (%)
fields.
Estimating exhaust air flow rate: There was no directly measured or ECU based exhaust flow rate data
available. As an alternative, ECU based intake air flow rate and fuel flow rate could be used to estimate
exhaust flow rate. However, the ECU based fuel flow rate (gal/hr) was compromised since the recorded
values were only integers. We used intake air flow rate (lb/min) as a surrogate for exhaust flow rate. Notethat even the intake air flow rate is reported in integer values, however since the units are lb/min there isless error from the lack of precision. Since this is a compression ignition diesel engine, the air to fuel ratio(AFR) is often above the stoichiometric point (lean operation) and a typical range of AFR would be 15 to50.
Other simplifications: The 1 hz mass/time rates did not account for wet vs dry adjustment and humidity
correction for NOx.
We estimate that using intake air flow as a surrogate for exhaust air flow and the other simplification
mentioned above would lead to an error of about 5% in estimating the final g/mile rates.
Examples of fuel flow rate and air flow rate data from the FTP-01 test

Fuel Rate (gal/hr)
5
4
3
2
1

1
56
111
166
221
276
331
386
441
496
551
606
661
716
771
826
881
936
991
1046
1101
1156
1211
1266
1321

0

Air Flow Rate (lb/min)

1
59
117
175
233
291
349
407
465
523
581
639
697
755
813
871
929
987
1045
1103
1161
1219
1277
1335

11
10
9
8
7
6
5
4
3
2
10

Mass/time estimates for 1 hz data: Pollutant exhaust rates in mass/time are estimated as:

mi= Me yi MWi

Wheremi= the mass per time for specie i, i = NO, NO2, CO2
Me= dry exhaust molar flow rate, mol air/s
MWi = the molecular weight for specie i, i = NO, NO2, CO2

Since we do not have Me we used Mair (intake air molar flow rate, mol air/s ) and the dry basis mole
fractions of measured species in the exhaust, yi, available from parSYNC:yi =[Yi , ppm]
106

yi =[Yi , %]100

Where:[Yi,ppm] = the concentration of measured specie i in ppm, i = NO and NO2[Yi,%] = the concentration of measured specie i in %, i = CO2
Final g/mile rates: The 1 hz mass/time rates are summed over the test cycle to get total grams ofpollutant. The 1 hz vehicle speed (in miles/sec) is summed over the test cycle to get total driving distance.
Total grams is divided by total distance to get mass/distance rates.

Results
2019 Ford F250
FTP72 Test-01
FTP72 Test-02
US06 Test-01
US06 Test-02

Rated Distance
(mi)
7.5
8.0

Test Distance(mi)

NO2(g/mi)NO(g/mi)NOx1(g/mi)

CO2(g/mi)

7.2

0.005

0.15

0.23

252

7.1

0.004

0.12

0.20

264

7.6

0.003

0.12

0.19

227

7.8

0.001

0.04

0.07

227

NOx is estimated using molecular weight of NO2 as per 40 CFR 1065.655 (c)(1). The language in theCode of Federal Regulation (CFR) is "Note that for calculating the mass of NOX emissions, you must use
the molar mass of NO2 for the effective molar mass of all NOX species, regardless of the actual NO2fraction of NOX."
1The NOx rates for the two repeats of the FTP72 are 0.23 g/mile and 0.20 g/mile. This compares very wellwith the CARB certification standard of 0.20 g/mile for this vehicle.
It is expected that the FTP75 cycle would lead to somewhat lower rates because the engine is warmed up.
On the other hand, the exhaust flow (in this pilot test) was based off the intake air flow and is expected tobe biased low compared to a more comprehensive flow measurement. Putting those two together, it isexpected that the results from the parSYNC system would be within 5% of a 1065 approved PEMS.

Graphs of NOx (g/s) vs Vehicle Speed (mph)2018161412108642060
504030201000200

400600800

1000

1200Vehicle Speed (mph)NOx (g/s)

FTP72 Test-01

-10
1400

Time (sec)

1460

1250

1040

830

620

410200-10
1400

0200

400

600

800Time (sec)

1000

1200

Vehicle Speed (mph)NOx (g/s)

FTP72 Test-02

60

NOx (g/s)

504030201000100

200300400500600

90807060
50
403020100-10Vehicle Speed (mph)70908070
60
50403020100-10Vehicle Speed (mph)US06 Test-01

Time (sec)

US06 Test-02
25NOx (g/s)

2015
10500100

200

300

400500600Time (sec)Second by second data with calculation of exhaust emission rates is available in an Excel file format uponrequestConclusions
Traditionally, chassis-based emissions testing of vehicles required the use of 1065 certified PEMS, which
while promising good accuracy, are difficult to setup due to their weight and complexity and expensive topurchase and maintain. Advances in recent years have made it possible to achieve similar levels ofmeasurement accuracy while significantly lowering the time, effort, and cost to own and use emissions
measurement systems.
The results from pilot test show that the parSYNC miniPEMS can provide excellent measurement
accuracy while simultaneously providing substantial benefits in ease of operation and significantly lower
costs as compared to a 1065 certified PEMS.

APPENDIX
GraphsCO2 (g/s) vs Vehicle Speed (mph)

860

750

640

530

420

3210

100-101400

0200

400600800

1000

1200Vehicle Speed (mph)

CO2 (g/s)

FTP72 Test-01

Time (sec)

860

750

640

530

420

32101000200400

600

800

Time (sec)

1000

1200-101400

Vehicle Speed (mph)

CO2 (g/s)

FTP72 Test-02

14CO2 (g/s)

12
108
6
4
200100200

300

400

500

600

90
80
7060
50
4030
20
100-10Vehicle Speed (mph)

1690
80
70
60
50
40
30
20
100-10Vehicle Speed (mph)US06 Test-01

Time (sec)

US06 Test-02
14
12CO2 (g/s)

10864200100200

300

Time (sec)

400

500

600

Test Cycles
Cycles: From DieselNet, https://www.dieselnet.com/
FTP-75

FTP-72 (UDDS)

US-06