Table I-1. California Title 13 Data Base

Lich 76 FOT1OY157695F 2 17274 18432 17.96 LILLO 4C00 140 2750 2 4F
Lich 76 F6R122143609 2:12.95 13-625 13.24 LILO OlLL 171 3500 2 9F
1101 75 2.8 5R112104089 2:11.47 11.14 11.09 11110 0011 171 3500 2
1101 74 2.3L 4R10¥166079 1 14.19 15.22 14.27 11200 C000 140 2750 2
1101 74 2.3L 4R11¥161237 1 15.03 15.96 15.06 11260 1000 140 2750 2
1101 75 2.3L 5R12¥142744 2 13.91 14.81 14.01 11110 1000 140 3000 2
1102 76 FOROZYIZL421F 2 17-41 1€-677 17.06 LILO 4000 140 3000 2 4F
1102 75 2.8 52122104101 2.12.40 12.03 13.26 11110 OOL1 171 3500 2
1102 74 2.3L  4FC3¥243623 1 13.64 14.35 13.49 112CO O11 140 3000 2
1102 75 2.3L 5R12¥142711 2 13.87 14.97 15.22 111210 0000 140 3000 2
1102 75 2.3L 5R1L1¥144644 2 14.94 14.38 15.33 11210 0000 140 3000 2
1103 76 FORL2Y134756F 2 16615 15486 16.31 LIL1O 4001 140 3000 2 4F
1103 76 F6R04Z142091 2.12.70 12.92 12.85 11110 4111 171 3500 2 9F
1103 76 FOROS2144176 2 12.39 12.32 12.42 LILLO OLE 171 3500 2 9F
1103 75 2.8 5R05Z106935 2 12.37 11.75 12.07 11110 1121 171 3500 2
1103 74 2.8L F4ROZZ181269F 1 12612 11.95 11695 11200 O101 171 3500 2
11C3 75 302 5RO4F 145439 2 10.79 10.47 11.05 11110 O1l11 302 3500 2
1103 75 302 5ROSF144154 2 10.58 10.28 10.96 11110 111 302 3500 2
1103 75 302 5RO4F145450 2 10.26 10.07 10.90 111210 111 302 3500 2
1104 76 FOK31F521679 2 11.61 11.76 11.71 11110 111 302 3500 2 10F
1104 75 FSK92L112557F 2 11434 11.36 11.39 11110 0111 250 3500 1 3F
1104 75 FSKOILI15473F 2 10.31 11.32 11.11 11110 0101 250 3500 1 3F
1104 76 FOKOLLIGL779F «= 2:12.44 12.52 12.74 11110 OLIL 250 3500 1 5F
1104 74 302 4K92F 179607 1 10.45 10.90 10.35 11200 0101 302 3500 2
1104 75 302 5K92F150123 2 8.28 8.69 8.96 11110 0111 302 3500 2
1105 76 Fon82F227316 2 10.66 10.58 10.68 11110 0121 302 4000 2 1OF
1105 76 F6W82F226347 2 11.06 10.86 11.32 11110 0111 302 4000 2 LOF
1105 75 FSw81L131128F 2 11.28 11.11 11.59 11110 111 250 4000 1 3F
1105 7€ FOWBIL186168F 2 11.52 11.56 11.63 11110 0111 250 4000 1 5F
1105 76 FOW82L187436F 2 12.45 12.48 12.59 11110 0000 250 4000 1 SF
1105 75 351W 5W84H171089 2 07.50 08.03 C7.50 11110 111 351 4000 2
1105 75 351m 5W83H178285 2 06.86 08.22 C7.58 11110 0111 351 4000 2
1105 75 302 SWB2F 200424 2 9.70 9.64 9.95 11110 0111 302 4000 2
1106 75 F5H31S159281F 2 08.28 08.44 08.63 22210 0111 400 5C00 2 oF
1106 75 F5J63S128932F 2 08.38 08.32 08.34 22210 0111 400 5000 2 6F
1106 74 351C 4G21H1 73565 L 8.88 8.90 8.58 012CO 0111 351 5000 2
1108 76 6G21AL60112 2 9.63 9.59 9.93 11110 0111 460 5000 4 LIF
1109 75 F5462S129230F 2 08.25 08.33 08.11 22210 0111 400 5000 2 oF
1109 76 6J62H130818 2 9.70 9.71 10.04 11110 O11 351 5000 2 6F
1109 76 6363H130835 2 9.58 9.56 9.82 11110 O11 351 5000 2 OF
1109 76 6J62H13C093 2 9.92 10.05 10.25 11110 0111 351 5000 2 oF
1109 74 351C — F4J62H142825 110.78 8.81 8.36 11200 0111 351 5000 2
1109 74 460 = F4J666141812 1 6.14 8.09 8.08 11200 111 400 5000 2
1109 74 40C F 45565143376 1 8.03 8.54 8.54 11200 0111 400 5000 2

1-2


Table 3-1. Carline Classes Common to Both the California Title 13 Data Base

and the EPA Certification Data Base

MODEL YEAR INERTIA WEIGHT (1b) cD CARBURETION TRANSMISSION
1975 3000 140 avi) Automatic
1975 4500 350 av Automatic
1975 5000 440 av Automatic
1975 5000 455 4v Automatic
1975 5500 455 4v Automatic
1976 4000 250 iv Automatic
1976 4000 304 2v Automatic
1976 4500 350 av Automatic
1976 4500 360 4v Automatic

(1) 2V corresponds to two Venturies, or barrels, in carburetor.


3301
2301
23C1
2304
3304
23C6
23C6
33C6
2306
41CL
4101
4101
41C2
4103
4103
4107
41C7
41C7
4202
4202
4202
4202
4202
4203
4204
4204
4204
4204
4204
42C8
43C1
43C1
43C1
4304
43C4
4304
4304
4305
43C6
43CEé
4306
43CO
4306
43C6

14
14
14
14
14
75
15
15
TE
15
75
Ts
75
15
75
75
75
15
15
15
16
76
Te
75
15
75
15
15
15
15
75
75
75
75
75
75
14
74
75
75
75
74
14

Table I-1.
RG VL29C4B497536
RG VL29C48473857
RG VL29C48483016
LA-4 RK41544208873
LA~4 PH41J40205823
CK41U50232982
PK41U5C0225195
OK41U5C227625
CLAS PP43J50134332
N-CB82  HLB210589673
N-082 HLB210095057
N-C82  HLB210591450
N-092 JKFL71C0027284
N-092 JHL710847027
N-092 JHL710847099
N-L1L2  #L530211996
N-112  #L530211943
N-1L1L2  HL530211026
2T-C TE31037186
2T-C TE37515043
2T-C TE31133646
2T-C TE31126289
2T-C TE31L126210
2T-C TE38013170
20R RT105010505
20R RTLLOCOIOLE
4y ¥X13020358
4u ¥X23012862
4M ¥X29018362
2cR RA22047938
2 1662014079
2 1152028468
2 1552014071
5 2252061012
5 2252062709
5 2252064912
i 2242140443
tee 4242045771
31 €252059776
31 3352102636
31 3352102760
4A 3242259933
4A 3242254785
4A 3242260166

mre NNN EE NNN NR RN NNN NR N RAN RN NNR NN NNN NNR NN

13.59
13.54
15.66
10.09
9.05
07.35
07.69
07.36
9.27
20.19
20.45
21.58
18.19
16.18
17.68
14.07
14.08
14.40
19.14
18.77
18.04
17.50
17.62
19.66
15.70
15.35
14.03
14.94
13.26
14.74
21.75
20.85
20.02
14.76
16.47
15.35,
14.92
16.92
20.63
20.17
19.80
19.94
20.13
20.09

13.44
13.44
15.61
10.09
9.04
07.47
07.48
07-61
9.30
22.09
20.45
23.05
18.84
16.13
17.58
13.09
13.38
13.59
18.83
18.CO
18.84
18.36
17.30
19.63
15.65
15.29
13.65
14.92
13.82
15.15
20.73
23.03
19.74
14.81
15.67
15.98
15.38
16.24
21.45
19.71
19.32
18.14
19.36
19.65

13.80
14.18
16.09
10.04

9.04
07.40
c9.07
07.49

9.28
22.30
19.55
21.56
19.17
15.69
17.67
13.49
14.09
14.33
18.97
18.84
18.65
17.74

18.74
15.77
15.79
13.72
14.77
13.29
14.14
21.27
21.49
20.70
15.05
15.06
15.20
15.39
16.90
22.82
19.80
20.30
18.79
20.82
20.CO

o11C0
01100
011C0
01100
o11C0
11110
112110
11110
11110
11110
11110
11110
11110
11110
11110
01010
01010
01010
11110
11110
10110
10110
1C€110
11110
11110
11110
11110
11110
11110
11110
01110
01110
c1110
01110
01110
o1llo
01Lco
o1ico
11110
11110
11110
110CO
110C0
11¢co

c1ol
o1ol
coco
olll
ollL
olll
Olll
o1ll
olll
4010
0010
4010
1000
1000
1000
0010
4010
4010
ococ
4C00
o110
4010
5010
cooo
4010
0010
oll
oll.
o1ll
5110
1000
ocoo
1000
cooo
1000
1000
0100
ooco
4010
0010
0010
1010
colo
colo

California Title 13 Data Base (Continued)

225
225
225
360
360
440
440
440
360
85
85
85
119
119
119
168
168
168
097
097
oT
oT
97
097
133
134
156
156
156
134
oT
97
a7
109
109
109
109
109
90
90
90
90
90
90

3500
3500
3500
4500
5coo
5000
5000
5000
5000
2250
2500
2250
2750
3000
3000
3c00
3000
3000
2500
2500
2500
2500
2500
2500
2750
3000
3c00
3000
3c00
2750
2500
2500
2500
2500
3500
3500
3500
2750
2500
2500
2500
2500
2500
2500

NNN BERK RKOOCOCOCOCONNNNNNANNNNNOCOONNNANNN SSS SSSR

3c
3c
3c

reed


CONTENTS

FOREWORD ......... ee ee eee Re ew ee eee » di
ACKNOWLEDGMENTS ...... ee ee wee be eee eee iii
SUMMARY . cee eee ee et eee eee eee eees Vil
1. INTRODUCTION. ......... eee rary tee ee seeee del
2. DATA ACQUISITION AND ANALYSIS. ........00.-000000. 2-1
3. RESULTS «0.2... 2... eee eee ee ee ee eee 3-1
APPENDIX I. CALIFORNIA TITLE 13 DATA BASE.......... eee Tt

APPENDIX II. FORMULAS FOR HARMONIC MEAN FUEL
ECONOMY AND THE TEST STATISTIC FOR
EVALUATING DIFFERENCES IN FUEL

ECONOMY ......- 2 ee eens beeen ee seen ee I-14
TABLES
1-1. Available Data from Three Data Sources ............08- ». 1-3
2-14. Highway-Urban Fuel Economy Correction Factors...... wee ee 2-2
3-1. Carline Classes Common to Both the California
Title 13 Data Base and the EPA Certification Data Base ....... 3-3
3-2. Models in Those Classes Common to Both the California
Title 13 Data Base and the EPA Certification Data Base ....... 3-4
3-3. Production Car Fuel Economy Study - Urban Results ....... oe 3-5
3-4, Production Car Fuel Economy Study Highway Results........ 3-6
3-5. Production Car Fuel Economy Study - Composite Results ..... - 3-7


where

Nj 2
s- ot >} (= - mpg;
JON; - i mpg; PE 5

Ny= number of cars in Jth class

mpBy = Mpg for Jth class

1,2


1110
Lik
LL
l1lL
Lill
1111
1201
1202
1202
1304
1304
1311
22C1
22c3
2204
2204
2204
2204
2204
2205
2205
2206
2206
22c7
2207
2208
2301
2301
2301
2302
2302
2302
2302
2302
2302
2302
2302
23¢3
2303
2303
2304
2401
2401
2401

14
76
15
14
14
14
75
76
15
75
15
14
75
75
75
15
75
74
14
14
14
14
14
75
75
75
7é
16
76
16
16
76
4
14
75
75
15
7
16
16
14
16
7é
if)

Table I-1.

400

460A
460
460
460
460A

460A
351W
302

351C

401-4
401-4
402-4
402-4
401-4
402-4

61J50
6150
6150
61V4
61V4
61V4
501-4
501-4
61V43
61V43
6143
61Vv0
61Vv0
61V0
501-4
1lwiv
1lwWlv
Liwiv

45745144113

F6J87A140551

5J87A136730

F4J587A157342F
F4JS8TALSTT96F
F4J87A158935F
5Y81A862062

F6Y89A873583

SY89A861314

5W37H533335

5W38F540282

4A93H549155

4$07C52115919
4B827C5L110937
4H57552122925
4557557122892
4E37C52114962
4IS57TIS41121742
4557342212032
4R45W4C108090
4R45T4C 108362
4N57J4C 108359
4P5714C 108355
4X39T5H441238
4X39TSH441288
4R35T5X112258
€S69R60459495
6S69R60459412
6S69R6Q0459024
6D47S6Q175543
6047860175378
6047860177463
6047R4A205385
6047R4A202985
6049850192145
6047850191381
6049856191224
6049860193541
6047866201523
6049860201432
6BE9R4A204980
1BO0BE6Y121584
18081 6¥119520
180816Y116399

NRNNENNANRNE RENAN NNN RNR EE RE RP RE NNN NRE RUNNER REN

7.70
8.76
07.62
07.32
07.68
07.36
08.37
8.69
07.94
07.10
9.34
8.62
14.20
12.44
12.10
10.65
11.80
09.56
08.86
06.47
06.21
08.60
06.56
8.39
9.46
8.89
10.43
10.58
10.32
08.82
08.59
08.95
8.25
7.87
9.06
9.33
9224
08.87
08.18
08.61
7284
19.29
19.24
20.96

7.71
8.87
07.55
07.24
07242
07.39
07.91
8.79
07.56
07.83
9.41
8.55
14.05
12.68
11.54
1b.t2
11.53
09.39
09.76
06.92
06.53
09.60
06.47
8.83
9.33
9.20
10.40
10.82
10.59
08.88
08.54
09.05
8.67
7.89
8.79
8.96
9.24
08.78
08.51
08.85
7299
19.54
20.35
21.19

I-3

8.16
8.95
09.39
C7.25
C7643
07.82
C7.87
9.05
08.02
07.49
9015
8.76
14.47
12.02
12.10
11.54
1L.61
08.73
09.25
C6.78
06.60
08.80
C6.57
8.87
9.41
9.05
11.21
11.49
11.21
09.04
o8.71
08.93
8.84
8.45
9.18
9.29
9.76
08.97
08.56
08.87
8.73
19.89
20.47
21.80

11200
11110
11110
110C0
11¢00
11000
LILLO
11110
11110
11110
11110
11200
Ollie
oll.
O1ll0
01110
oun.
11100
11100
11160
11100
11100
11160
O1oLL
01011
o10n1L
11010
11010
11010
11110
11110
11110
11200
11200
Li.
lita.
dllli
1110
11110
11110
11200
11110
11110
11110

111
0111
0111
0111
oul
0111
o1ll
o1ll
oul
0111
0110
0111
oul.
0111
oll
o1ll
oil)
0111
oll
0111
o1ll
o1nt
0111
oul
0111
0211
0111
0111
Olli
O1lL
0111
out
o11L
o1nl
oll
o1nl
Olt
oll
0111
0111
ull
0100
1000
0000

California Title 13 Data Base (Continued)

400
460
460
460
460
460
460
460
460
351
302
351
231
231
350
350
23h
350
350
455
455
350
455
455
455
455
350
350
350
500
500
500
472
472
500
500
500
500
5co
500
472
098
08s
08s

5500
5500
5500
5500
5500
5500
5500
5500
5500
4000
4000
4500
3500
4C00
4500
4500
4000
4500
4500
5500.
5500
5000
5500
5500
5500
5500
4500
4500
4500
5500
5500
5500
5500
5500
5500
5500
5500
5500
5500
5500
5500
2250
2250
2250

Hmm POCO PD LAD HS PROOCOHL HDDS DEL ENEENNNNNS SHS SDSSDN

7GM
7GM
136M
13GM
7GM

26M
26M
26M


Table I-2. Format of California Title 13 Data Base

COLUMNS DATA

1-4 Model Code*

6-7 Model Year

9-14 Engine Family

16-30 Vehicle ID

32 Test Type*

34-38 mpg

40-44 mpg Repeat Tests
46-50 mpg

52 Air

53 EGR Devices*
54 EM

55 CAT

56 FE

60 Transmission Type*
61 Air Conditioned

62 Power Brakes

63 Power Steering Accessories*
65-67 CID

69-72 Test Weight (1b)

74 Carburetion*

%See Table 1-3

1-9


2505
25C5
25C6
2506
2601
2604
2604
2604
2604
2604
26C5
2605
2606
2606
26C6
26C8
2608
2609
2609
2609
3001
30Cl
30cL
3CCl
3CC3
30c3
3CC3
3CC3
3CC4
30C5
30Cc5
3cc5
3201
32CL
3202
32C4
3204
3205
32C7
3208
3208
3208
3208
3208

75
75
75
75
75
76
ais
76
74
14
75
76
75
Té
4
75
7é
75
75
75
75
15
75
75
75
15
15
74
75
75
14
74
75
15
716
76
75
14
TE
75
75
75
75
75

Table I-1.

31443

11023
B1H25
B1H2S
1LFL

201-4
201-4

21K4

21K4
201-4

21K4

CLA4
CLA4

RB

RB
RB
CLA2
CLA2

CLA2
LA-4

3N39T5X112369
3N39K5X132669
3X37TSML96471L
3X37TSMLTLT54
2V77B5C 106344
2Y27F6L103492
2Y1L7F6L103501
2Y69D6L 104678
2217B4L131459
2217B4L131460
2S87E5N515109
2T87P6N537924
2F37E5P150816
2F37P6P201204
2Z17B4L131464
2K57W5P182930
255 7P6P197482
2P49S5X135705
2R49W5X 148464
2L45W5X148145
SS22N5R266779
$S22N5R281690
$$22J5R130592
$S22J5R143299
CS23T5C164462
CS23T5C177722
CS41LTSC191136
€S23T4C179422
YM23T5C140115
CS46TSC254914
CP46T40197442
CP46T40205193
LL2965G6111638
LH41G5R140853
NH41G6B107738
WH41G6A136109
wWH41G5A136860
WP2954A140521
WH23G6G113584
CK41N50222030
DP43T5D150018
OK41U5C191408
CK41U50194301
CK41U5C0227622

NNN NNN PNR NNN BEER NEN ANN NNN NR NNER RRR EE NUNN

9.78
8.93
9.31
9.58
18.43
11.16
11.50
11.98
9.00
8.81
10.17
11.72
9.17
10.62
9.01
8.42
10.70
8.93
8.58
7.86
09.48
09.58
10.86
10.31
08.31
08.61
08.02
B92
07.72
07.95
7.90
8.90
11.CO
10.18
10.77
10.69
10.18
9.13
10.65
08.88
07.63
08.04
07.70
o7.71

10.08
9.86
9.79

10.03

21.24

11.11

12.03

13.02
9.78
8.46

10.39

12.04

10.02

11.03
8.79
9.07

10.95
8.99
9.03
8.56

08.74

08.55

10.97

10.24

07.95

08.22

08.co
8.74

07.47

07.52
7.65
9.09

11.C1

10.16

11.01

10.66

10.27
9.17

10.48

08.5C

07.79

08.05

07.52

07.71

I-5

9.75
9.54
9.53
9.96
18.68
11.27

8.74
8.59
10.49
12.12
9.43
11.17
9.01
8.70

8.97

8.64

7.93
10.19
09.04
11.31
10.36
08.02
08.67
oe8.cs

8.90
07.54
C7.98

8.02

9.08
10.89
10.26
10.71
10.39

9.89

9.49
10.73
08.99
C7287
08.30
08.19
08.13

O1o0iL
11010
oll
O1oll
11110
01110
01110
11110
a1ico
01100
11010
11110
11010
11110
01100
Old.
11110
01011
OWL
OULLL
11110
11110
11110
11110
11110
11110
11110
11100
11110
11110
11100
111C0
11110
11110
11110
11110
11110
o1ico
11LLO
11110
11110
11110
11110
11110

olll
oll
Olli
O1lL
1100
oll.
oll.
ollL
olll
o1ll
Olli
Olll
O1ll
o1li
olll
0100
OllLL
OllL
Olli
OllL
oLll
oll)
oO1ld
olll
olll
oll.
OllL
Olli
O1lL
oll.
Olll
oll.
Olll
Olpl
ollL
ollL
Olll
onli
Olll
o1co
oll.
O1lL
OlLL
oll.

California Title 13 Data Base (Continued)

455
350
455
455
140
260
260
250
350
350
350
350
350
350
350
455
350
400
455
455
400
400
360
360
440
440
440
440
440
440
440
440
318
318
318
318
318
30
318
460
440
440
440
440

5000
5c00
5000
5000
3000
4000
4000
4000
4cco
4C00
4000
4000
4500
4500
4000
4500
4500
5000
5000
5500
4500
4500
4500
4500
5500
5500
5500
5000
5500
5500
5500
5500
4C00
4500
4000
4500
4500
4500
45C0
scoo
5500
5000
5c00
5000

PRD PANE ENN ES DEE EDAD EDD APE RRA ERLE PRR ERENNNS ERS

36M

3GM
3GM

16M

16M

46m

1GM
46M
46M
4C
4c

5c
2c
2c

5C
2c

ic
ic

1c
4C
5C
3c
3c
3C


TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)

REPORT NO. 2. 3. RECIPIENT'S ACCESSION NO,
EPA -460/3-76-027
4. TITLE AND SUBTITLE Is. REPORT DATE
October 1976
Analysis of Production Cars' Fuel Economy 6, PERFORMING ORGANIZATION CODE
7 AUTHOR(S) ls. PERFORMING ORGANIZATION REPORT NO.
Dr. Ronald F, Janz ATR-77(7358-03)-1
J9. PERFORMING OR TANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT NO.
The Mobile Systems Group
Environment and Energy Conservation Division 11, CONTRACT/GRANT NO.
The Aerospace Corporation
El Segundo, California 68-01-0417
12. SPONSORING AGENCY NAME AND ADORESS 13, TYPE OF REPORT AND PERIOD COVERED
EPA Office of Air and Waste Management
Office of Mobile Source Air Pollution Control 14. SPONSORING AGENCY CODE
Emission Control Technology Division
Ann Arbor, Michigan 48105

15. SUPPLEMENTARY NOTES:

16. ABSTRACT

Harmonic mean fuel economies, in miles per gallon, were computed for nine
carline classes which were common to the California Title 13 Data Base and the
U.S. Environmental Protection Agency (EPA) Certification Test Data Base for
1975 and 1976 model years, The parameters used to define a carline class were:
model year, inertia weight, cubic inch displacement, number of carburetor
barrels, and transmission type.

Both urban and highway fuel economies determined from the California Title 13
data were found to be consistently lower (urban: 5 to 19%; highway 6 to 23%) than
corresponding fuel economies determined from the EPA certification data. These
differences may be at least partially explained by the typical mileage accumulation
of 20 to 120 miles for the California tested cars compared to the 4,000 miles
accumulated on the EPA prototype certification test vehicles.

KEY WORDS AND DOCUMENT ANALYSIS

a DESCRIPTORS Ib IDENTIFIERS/OPEN ENDED TERMS |c. COSATI Ficld/Group
Motor Cars 13F
Fuel Economy
8. DISTRIBUTION STATEMENT 19, SECURITY CLASS (This Report) 21, NO, OF PAGES
tend Unclassified
Unlimited 20, SECURITY CLASS (This page) 22. PRICE
Unclassified

EPA Form 2220-1 (9-73)



Table 3-5, Production Car Fuel Economy Study - Composite Results

Sales Weighted: No
Minimum Number of Cars Per Class: 3
Critical Value of Test Statistic at .05 Significance Level = 3.84146

MEAN FUEL ECONOMIES test statistic?)
CLASS EPA Cert Calif Title 13 EPA-Calif
530014020 19.8 17.8 8.9
545035040 13.0 12.4 0.8
550044040 10.8 9.0 32.4
550045440 11.8 10.8 2.4
550045440 11.3 10.0 1.6
640025010 16.6 14.4 22.8
640030420 13.3 12.3 7.7
645035040 15.0 12.4 46.5
645036040 13.3 11.0 19.4

(1) Defined in Appendix II.

3-7


SECTION 2

DATA ACQUISITION AND ANALYSIS

The California Title 13 Data Base was constructed from data acquired
from the CARB, El Monte, California. A listing and description of this data
base is given in Appendix I, Three miles-per-gallon (mpg) values (from re-
peat tests) were recorded for each car. Arithmetic mean values were used
to represent individual car fuel economies. For all carline classes which
were common to this data base and the EPA Certification Test Data Base, the
mpg values corresponded to the 1975 urban test procedure. Highway values
were obtained by the use of the factors supplied by the EPA Project Officer
and are summarized in Table 2-1. Composite values were obtained from the

following formula:

(1)

TMPE composite “0. 55/mP By ban.

1
y+ (0.457 mP Bhi chway)
(The above formula and factors were used only in conjunction with the California
Title 13 data since highway and composite fuel economies were supplied directly
in the EPA Certification Test Data Base.)

As indicated in Section 1 of this report, four design parameters were
used to characterize an individual carline class: inertia weight, cubic inch
displacement (CID), number of barrels in the carburetor (or fuel injection),
and transmission type (automatic or manual). Those cars whose inertia
weights differed by a few pounds or CID by a few cubic inches were grouped ir
the same class. For example, cars with inertia weights of 5501 lb were
grouped together with cars whose inertia weights were reported as 5500 lb.
Similarly, cars with a CID of 302, 304, or 305 were grouped together in the
same class. With respect to the nine classes considered in this study, the only

relevant grouping parameter is the CID; e. g., one California Title 13 class


Table I-4. Engine Family Code

COLUMNS 76-79 CODE FOR ENGINE TYPE

1c CD-318-2-P5S
2c C-RB-CAP-II
3G C-RB-HP-CAP
4c C-B4-CAP

5C C-RB-CAPIL
1GM 21K43-F

2GM 41543 /0

3GM 31843F /0

4GM 21843E/0

5GM 61V43

6GM 113234 /0

71GM 41E23/0

8GM 31H23E/0

9GM 11F13A /0
11GM 6130
12GM 31543
13GM 41343 /0

3F 250 (ICEE) (Trucks, Vans)
4F 2.3 (ICEF)

5F 250 (1 CEF)

6F 351 m/400 (2 CET)
TE 2.3L

8F 302

oF 2.8L (2CEF)
10F 302 "A"! (ICEF)
11F 460 "A"! (2CMT)

I-15


Table I-3.

Manufacturer

Ford Ford
I 1
Lincoln
2
Mercury
3
General Motors Buick
2 2

Division

California Title 13 Data Base Codes (Continued)

Model

01 Pinto

02 Pinto Wgn.
03 Mustang IL
04 Maverick

05 Granada

06 Torino

07 Torino Wgn.
08 Elite

09 Ford (Cust. 500, Galaxy, LTD)
10 Ford Wen.
11 Thunderbird

01 Continental
02 Continental Mk IV

01 Bobcat

02 Bobcat Wgn.
03 Comet

04 Monarch

05 Montego

06 Montego Wgn.
07 Monterey

08 Monterey Wgn.
09 Marquis

10 Marquis Wgn.
11 Cougar

01 Skyhawk
02 Apollo

03 Skylark

04 Century/Regal
05 Century Wgn.
06 Le Sabre

07 Electra

08 Estate Wen.

09 Riviera


SECTION 1

INTRODUCTION

The objective of this study was to compare fuel economies from three
sources: (1) The California Title 13 Data Base Tests, (2) The U.S. Environ-
mental Protection Agency (EPA) In-Use Compliance Test program, and (3) The
EPA Certification Test Data Base.

The California Air Resources Board (CARB) testing of production
vehicles, authorized under Title 13 of the California Administrative Code, has
as its objective the emission testing of new production vehicles, with primary
attention given to those engine families which just barely meet the California
emission requirements during the EPA certification tests. Mileage is accu-
mulated on these vehicles prior to testing over an approved durability driving
schedule. The CARB permits each manufacturer to specify the mileage ac-
cumulation it considers necessary to overcome the ''green-engine" effect from
an emissions point of view. Typical mileage accumulation varies from 20 to
120 miles compared to the 4000 miles accumulated on the prototype certifica-
tion test vehicles. The CARB tests about 80 engine families per year.

The In-Use Compliance Test program is conducted by the EPA to
monitor the emissions performance of production vehicles as tested after the
cars are in operation. This data base consisted of 4950 vehicles covering the
1972 through 1974 model years.

The EPA Certification Test Data Base incorporates the fuel economy
data for 1975 and 1976 model year vehicles as determined from the EPA emis-
sions certification test results. This data base includes 759 vehicles for the
1975/1976 model years. Of this total, 277 vehicles were equipped to meet the
California emission standards. The remainder were equipped to meet the
Federal emission standards.

Data from the first source did not exist in a form suitable for analysis

at the beginning of the study. However, an appropriate data base was developed

1-1


SUMMARY

Harmonic mean fuel economies, in miles per gallon, were computed
for nine carline classes which were common to the California Title 13 Data
Base and the U.S. Environmental Protection Agency (EPA) Certification Test
Data Base for 1975 and 1976 model years, The following parameters were
used to define a carline class: model year, inertia weight, cubic inch dis-
placement (CID), number of carburetor barrels, and transmission type. A
class was considered to be acceptable for analysis if it contained at least
three cars.

Both urban and highway fuel economies determined from the California
Title 13 data were found to be consistently lower (urban: 5 to 19%; highway:

6 to 23%) than corresponding fuel economies determined from the EPA certi-
fication data. However, the statistical significance of this result could not be
assessed since the test for statistically significant differences is an asymp-

totic test requiring a larger number of cars per class than were available for

analysis in this study.

vii


APPENDIX |

CALIFORNIA TITLE 13 DATA BASE

A listing of the California Title 13 Data Base is given in Table I-1.
Each line of information corresponds to a different car. The format of these
data is given in Table I-2 with additional explanations of the coded information
in Table I-3. In some instances, the engine family designation involved more
characters than were provided for in the standard format. When this occurred,
a code for the engine family was put into columns 76 through 79. That code
is interpreted in Table 1-4. The occasional ''X'' which appears in column 80
means that at least one inconsistency in the data was recorded on the original
test forms.

I-1


The data which were available for this study, organized according to
model year and California versus the other 49 states, are shown in Table i-1.
It is clear from this table that, given these data, comparisons between data
bases can only be made for California cars in model years 1974 through 1976.
However, it was found that the comparisons were further restricted by the
fact that there was an insufficient number of 1974 model year cars in the EPA
In-Use Compliance Test Data Base to compare with corresponding cars in the
California Title 13 Data Base. In the In-Use Compliance Test Data Base, the
date of purchase was used to determine the model year, while the test site
was used to determine the California cars. A carline class could not be identi-
fied which contained at least three cars purchased after September 1, 1973
and tested in Los Angeles. Consequently, it was not possible to use the EPA
in-use compliance data in this study. Asa result, only comparisons between
the EPA Certification Test Data Base and California Title 13 Data Base for
model years 1975 and 1976 were made.

Table 1-1. Available Data from Three Data Sources

MODEL YEAR
_STATE 1972 1973 1974 1975 1976

California In-Use't) In-Use In-Use Epa’) EPA
Title 13) Title 13 Title 13

49 States In-Use In-Use In-Use EPA EPA

(1) Data from EPA In-Use Compliance Test programs,
(2) Data from California Title 13 tests.
(3) Data from EPA vehicle certification tests.

1-3


4307
4368
4308
4401
4401
4401
4401
4401
44cl
4401
4401
4401
4401
4402
4402
4402
4402
4402
4462
4403
4403
4403
4403
4403
4403
4403
44C4
4404
4404
4404
4404
4405
4405
44C5
4405
4405
4465
4405
4405
4405
4405
4405
4405
4405

75
75
75
76
76
76
76
7é
14
74
1S
756
75
716
76
Te
716
Té
TE
7é
76
74
74
715
75
75
76
76
Té
7é
75
76
7é
76
76
76
76
7é
7é
Té
76
76
74
14

Table I-1. California Title 13 Data Base (Continued)

te
bepetet
araqqaqang

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AGR465E1 16741
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AGC465A107114
A4A465E347260
AGA465A331873
ASE465E172340
A5A465E137436
ASC465A228191
AGEGETALIT267
A6CE67A101782
AGAEETE2Z47765
A6A667A240208
AGAGETA2Z40127
AGAEETE2Z51 866
A6C037H147382
AGACSTALZ97T9L
A4A057A330962
44C037H351880
ASA067A131094
ASA037TA222602
ASAOSTH213876
AGANBTA240T06
AGACBTH229423
A6A0BTH234716
A6COBTH238744
AS5AC87TH109672
A6ALGTH104089
A6C167H104073
A6A167H104307
A6A857H238230
AGA167H240783
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B6A167P219038
AGALOTPL28547
AGALOTNILLOG3
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AGAL67N119534
A4AL67TH350512
£4C167H350530

MPN N NUNN NN ANN NEN NAN EE BENNER NNR NNR RE ER RNR NUNN ND

18.24
20.20
20.91
12.57
14.07
12.13
11,42
12.06
14.28
12.13
15.01
11.36
11.48
13.53
11.68
12.25
12.26
11.30
11.34
11.72
11.49
10.48
11.09
11.60
10.93
11.25
11.50
10.37
10.05
10.13
10.61
11.02
11.20
10.04
10.16
10.75
10.47
09.17
10.12
08.85
09.69
09.66
10.20
09.86

21.02
21.64
20.36
12.55
13.70
12.22
11.61
12.56
13.94
12.01
16.08
12.87
11.54
13.67
11.73
12.20
11.81
11.29
12.04
11.71
11.79
10.25
10.82
12.67
11.08
11.11
11.51
10.52
10.16
10.43
11.52
10.96
11.41
10.03
10.46
10.67
10.80
09.22
10.27
08.94
09.66
09.43
10.09
10.56

I-7

20.25
21.10
20.15
12.08
14.17
12.26
11.62
12.49
14.60
12.56
16.12
12.18
12.03
15.38
11.23
12.49
11.85
11.29
12.54
12.77
11.77
10.76
11.24
12.44
11.00
13.82
11.55
10.41
10.23
10.34
11.40
10.86
10.77
10.53
10.21
10.96
11.01
C9219
10.C8
C9202
09.63
C9.74
10.34
10.10

11110
11110
11110
11110
11110
11110
11110
11110
01100
o11co
11111
LM.
110lL
11110
11110
11110
11110
11110
11110
11110
11110
O1LCO
111¢0
11111
11011
lit
11110
11110
11110
11110
iit
11110
11110
11110
11110
11110
11110
11110
11110
11110
11110
11110
11000
11100

co10
4010
4010
ccol
1c00
co000
cool
Olli
coco
0100
1000
olll
oool
1001
olll
co0o0
cool
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coll
OllL
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0101
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olol
cool
ollL
oOlll
oll.
o10l
olll
C101
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OuLL
Olll
Olll
o1ll
Olli
Olli
olll
Olli
oll.
ollL
Olli
Olli

90

90

90
232
232
232
258
258
232
258
232
232
258
258
258
232
258
258
232
304
258
258
304
258
258
304
258
304
304
304
304
304
304
304
304
304
304
360
360
360
360
360
304
304

2250
2250
2250
3500
35C0
3500
3500
3500
3000
3000
3c00
3000
3000
3500
3500
3500
3500
35C0
3500
3500
3500
3500
3500
3500
3500
3500
3500
4000
4000
4000
3500
4500
4500
4500
45C0
4500
4500
4500
4500
4500
4500
4500
4000
4000

RNNNN FS ANNNNNNANNNRERN ERR EERE EP PPP Re Pe RPP EE RNIN


|

| EPA-460/3-76-027
October 1976

ANALYSIS
OF PRODUCTION

CARS’
FUEL

ECONOMY

U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Mobile Source Air Pollution Control
Emission Control Technology Division
Ann Arbor, Michigan 48105


SECTION 3

RESULTS

The nine classes of cars which were identified as common to both the
California Title 13 Data Base and the EPA Certification Test Data Base are
listed in Table 3-1. The individual models for each class are given in
Table 3-2.

Harmonic mean fuel economies for each of the classes are listed in
Tables 3-3 through 3-5. The test statistic (Appendix II) listed in these tables
can ordinarily be used to determine whether the differences in fuel economies
indicated in these tables are statistically significant at a given significance
level. For example, if the value of this test statistic exceeds 3.84146 then
the hypothesis that the mean fuel economies are the same is rejected ata
0.05 significance level. (The formulas which were used to compute the har-
monic mean fuel economies and the test statistics are given in Appendix II.)
Since this is an asymptotic test, it is not strictly applicable to the small classes
considered in this study. The values given in these tables should therefore
be treated with caution. It is apparent, however, from Tables 3-3 through
3-5 that the harmonic mean fuel economies based on the California Title 13
data are consistently lower than those based on the EPA certification data.
These values vary from 5 to 19% lower for urban driving and from 6 to 23%
lower for highway driving.

These results should be considered preliminary in nature since only
a limited number of cars were analyzed in this study. However, the differ-
ence in fuel economy between these data sources can be at least partially ex-
plained by the ''green-engine" effect. As indicated in Section 1, typical mile-
age accumulation for the cars tested by the CARB varied between 20 and 120
miles compared to the 4000 miles accumulated on the EPA prototype certifi-

cation test vehicles.


consists of two Novas (CID = 305), a Camaro (CID = 305), and three Hornet
wagons (CID = 305). This class was compared with an EPA certification class

consisting of three Monarchs (CID = 302)(Section 3, Table 3-2).

Table 2-1. Highway-Urban Fuel Economy Correction Factors

MODEL YEAR

MANUFACTURER 1975 1976
General Motors 1.384 1.399
Ford 1.470 1.380
Chrysler 1.428 1.404
American Motors 1.346 1.352
Volkswagen 1.546 1.498
Toyota 1.489 1.504
Nissan 1.449 1.419


Table I-3. California Title 13 Data Base Codes (Continued)

Manoulacturer Division
Nissan Datsun
4 1
Toyota Toyota
4 2
Volkswagen Volkswagen
4 3

09

10
ll
12

ol
02
03
04
05
06
07

ol
02
03
04
05
06
07
08

ol
02
03
OF
05
06
07
OB

Model

Pontiac (Bonneville, Catalina,
Grandville)

Pontiac Wgn,
Grand Am

Trans Am

B-210
710

710 Wen.
610

610 Wen.
2602
2802

Corolla 1200
Corolla 1600
Corolla 1600 Wgn.
Corona

Corona Wen.

Mk IT

Mk II Wen.

Celica

Beetle
Ghia
Thing
Van
412
Dasher
Rabbit

Scirocco


Table I-3.
Manufacturer Division
General Motors Cadillac
2 3
Chevrolet
4
Oldsmobile
5
Pontiac
6

I-43

California Title 13 Data Base Codes (Continued)

Model

01 Seville
02 Calais /Deville,

03 Eldorado

04 Fleetwood Brougham
05 Fleetwood 75

01 Chevette
02 Vega

03 Vega Wen.

04 Monza

05 Nova

06 Camaro

07 Chevelle (Malibu, Laguna)
08 Chevelle Wgn.

09 Chevrolet (Caprice, Impala, Bel Air)

10 Chevrolet Wgn.
11 Corvette
12Monte Carlo

Ol Starfire

02 Omega

03 Cutlass

04 Cutlass Wgn.
05 Delta 88

06 Ninety-Eight
07 Cust, Cruiser Wgn.
08 Toronado

01 Astre

02 Astre Safari
03 Sunbird

04 Ventura

05 Firebird

06 Lemans

07 Lemans Wen.
08 Grand Prix


by hand-transcribing data from test results kept on file at the CARB office in
El Monte to keypunch coding forms. A card deck consisting of data on 271
cars for model years 1974 through 1976 was then generated from these forms.
Data from the other two sources were supplied by the EPA Project Officer on
magnetic tape.

Many factors affect fuel economy. Those which were singled out for
this study are as follows: inertia weight, cubic inch displacement (CID),
number of barrels in the carburetor (or fuel injection), and transmission type
(manual versus automatic). These parameters were used to define an indi-
vidual carline class. Other parameters, such as axle ratio, number of gears
in the transmission, and whether the car is air conditioned, also may have an
important effect on fuel economy. However, when additional parameters are
used to define a carline class with a relatively small data base, it becomes
increasingly difficult to find enough cars which have these parameters in com-
mon so that meaningful mean fuel economies can be determined and compared,
statistically, with other mean values. In order to assure that the data bases
could be compared on a carline basis, three cars per class were considered
to be the minimum acceptable number. The dispersion in fuel economy was
generally small enough in these classes that mean values could be used to
characterize a class. Since the test for differences between harmonic mean
values adopted by EPA in the FY 72 Automobile Exhaust Emission Surveillance-
Analysis Program (EPA-460/2-74-001, Appendix III) is an asymptotic test,
it is not strictly applicable to classes this small in size. However, the test
statistics for comparing mean fuel economies (Appendix II) were computed
and are tabulated in Section 3 of this report.

The emission control equipment used by various manufacturers, in
general, also affects fuel economy. Consequently, cars intended for operation
in California were distinguished from those designed for the other 49 states in
defining a carline class. Also, since this equipment may change from one year
to the next because of changing emission standards, the model year was used

to define a carline class.

1-2


2402
2402
2402
2402
2402
2402
24C2
2402
2404
2404
2464
2405
24C5
24C5
2405
2405
24C5
2405
2465
24C5
2406
2406
24CT
24C7
24C7
24C9
2409
2409
2409
2410
2410
2412
2412
2412
25C2
25C2
25C2
25C2
2503
25C3
25C3
25C3
2503
25C3

Table I-t.

11€23 1V77B5C109997
11023 1¥7785C109965
1Ol-2  1¥7784U298261
101-2 = 1V77B4U298314
101-2 1V77B4U305492
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1C1l-1 = LV77A4U304894
LOL-t = LV15A4U305225

1M27H5C247321

1M27THSC246824

1M27H5C247552

1X6905L149260
1162 1Y¥69Q6L 117092
1162 1Y¥6SQ6L117483
LLFL 1X27D6L123960
LLFL 1X69D6L124136
1C2-1 = -1X27D4L195071
102-1 1X2704L195058
102-1 =1¥1704L194960
104-4 = 1X27L4L167396

1Q6705N591513
11G2 1087Q6N540239

1037052454756
LLK4 1035L62421918
1L1K43) 1035152444878
11K43) -1N39U55194043
104-4 = 1LE9L4C149202
104-4 1N69U4C148487
1C5-4 =2L35Y4C148917
105-4 = 1N35Y4C149132
105-4 = 1N4S5Y4C1488S9
11LK4 LHS 7L62422055
1LK4 1H57L62422028
Y1K43° 0 LHS7L52444872

3B69J5L113306

3S27F5L111581
Blk2J 381 7F6L 103230
3O1-4 =3B27K4L122426

3ISTF5R140584

3F3ITF5R140254
3C1-4 «3495 7K4R192929
301-4 «35 7K4R192559
31943) 3529K5R154916
21343) 3557K5R154858

NNR BERN RRNA NR RR RR RR NNN NN EEE PENNA NE EE RENN

16.44
15.76
14.85
16.85
13.73
13.87
18.49
19.19
12.31
11.14
11.69
11.37
11.06
11.00
13.02
12.49
13.67
11.98
11.17
09.79
11.92
11.36
10.81
09.48

9.36

9.41
09.13
07.49
08.03
07.89
07.82
10.29
10.04

9.34
11.61
11.17
12.1¢

9.33
10.30
10.60

9.50

9.50
10.01
10.08

16.40
16.08
15.41
16.00
15.04
13.49
20.28
20.36
11.89
11.48
11.28
11.32
11.35
11.48
13.65
13.15
13.35
11.98
11.01
09.41
11.89
11.65
11.68
09.56

9.72

9.70
08.86
07.39
07.99
07.67
07.72
10.48
10.19
10.13
11.64
12.36

9.78
10.28
10.71
10.01

9.96
10.21
10.15

I-4

16.16
15.88
15.90
17.61
14.18
14.33
18.72
19.80
12.04
11.54
11.35
10.98

11.47
13.25
13.08
14.14
12.28
11.20
C9284
12.16
11.61
11.14
C9244

9247

964k
09.34
C7.61
08.11
C7.77
C7.73
C9294
10.37

9.16
11.74
11.66

9245
10.65
10.63

9.62

9.73
10.97
10.81

11110
11110
01200
012C0
o1ico
012c0
o11co
o11co
11110
11110
11110
11110
01110
01110
11110
11110
112¢c0
112c0
112c0
110C0
Litt
o1110
Liat
11110
LVL
lian
110C0
110C0
11000
11¢CO
11Cco
L1LLO
11110
Litht
01110
c1llo
O1llod
o11co
O1LLO
o1llo
01100
011C0
11010
11010

California Title 13 Data Base (Continued)

oo0o0
0100
1100
1100
1101
cooo
1000
1000
coll
Olll
olli
coco
ollL
OLld
Ollt
OllL
1000
oooo
cool
o1oL
ool.
coll
Olll
ollL
ooo
Obl
oll
OllL
oll)
Olli
OllL
oll.
Olll
Olli
Olli
OL
oll.
OLlt
OllL
Olli
oll.
ollt
OllL
oll

140
140
140
140
140
140
140
140
350
350
350
250
305
305
250
250
250
250
250
350
250
305
250
350
350
400
350
400
454
454
454
350
350
350
350
260
260
350
260
260
350
350
350
350

3000
3000
3000
3000
3000
2750
2750
2750
3500
3500
3500
4000
40C0
4C00
3500
4000
3500
3500
4C00
4000
4C00
4000
4c00
$000
5000
5coo
4500
5C00
5500
5500
5500
4500
4500
4500
4000
4000
4000
4000
4500
4500
4500
4500
4500
4500

PRE PUNENN EDD SSD LER ESPEN PER PRP ENN EN NNER ENR

6GM
6GM
6GM
9GM

9GM

9GM

13GM
8GM

8GM
8GM


Model Code -

Type Test

Devices

Transmission

Accessories

Carburetion

(Venturi)

Table I-3. California Title 13 Data Base Codes

See Below (Ex: Dodge Coronet = 3204)

CVS-I=l (Urban, 1972)
CVS-U=2 (Urban, 1975)

Air = Air injection 0=Not installed
EGR =Exhaust gas recirc. 1=Installed
EM=Engine Modification 2=Not recorded

CAT=Catalyst or OC
FE=Fuel Evaporization or EFE

0=Automatic

1=Manual - undefined

3=Manual 3 speed primary on U.S. cars
4=Manual 4 speed primary foreign, Opt. U.S.
5=Manual 5 speed Optional on foreign, U.S.

0=No
1=Yes

2=Not recorded (no summary sheet)

0=Fuel Injection

l= 1 BBL

2= 2 BBL

4>4 BBL

5= Undefined :


ACKNOWLEDGMENTS

During the course of this study, Mr. J. Dillard Murrell of the U.S.
Environmental Protection Agency (EPA), Emission Control Technology
Division, served as the EPA Project Officer and provided valuable guidance
and assistance. His efforts are gratefully acknowledged.

Dr. R. F. Janz of The Aerospace Corporation was principally

responsible for the analysis effort. The following technical personnel of The
Aerospace Corporation also made valuable contributions to the analyses per-
formed under this contract:

W. M. Smalley

P. L. McGill
E. Lamken
S. Cheung
K. A. Glaser
D. A. Oster

L. Forrest, Director
Vehicle Performance Office

Mobile Systems Group

Approved by

QL Keaton

M. G. Hinton, Group Director

Mobile Systems Group
Environment and Energy Conservation Division

nvironment and Energy Conservation Division

iii


Fre

Table 3-2.

Models in Those Classes Common to Both the California Title 13
Data Base and the EPA Certification Data Base

CLASS* CALIFORNIA TITLE 13 EPA CERTIFICATION
530014020 Pinto (2), Vega (2) Mustang IJ, Bobcat Wgn, Monza, Astre
545035040 Century/Regal (2), Monte Carlo, Monte Carlo, Cutlass, LeMans
Cutlass, LeMans
550044040 Monaco (3), Fury (3) New Yorker (3)
550045540 Delta 88, 98, Granville 98, Granville (2)
555045540 Electra, Estate Wgn, Granville Riviera, 98, Pontiac Wgn
640025010 Granada (2), Nova, Ventura Granada (2), Cutlass (2), Chevelle
640030420 Nova (2), Camaro, Hornet Wgn (3) Monarch (3)
645035040 Grand Prix, LeMans, Monte Carlo (2) LeMans (2), Monte Carlo, Century/Regal,
Cutlass
645036040 Matador (2), Matador Wgn Coronet (3)

*Class Code: Digit 1
Digit 8

now

Model year, Digits 2-4 = weight/10, Digits 5-7 = CID,
Carburetion, Digit 9 = Transmission (see Table 3-1),


Table 3-4, Production Car Fuel Economy Study - Highway Results

Sales Weighted: No
Minimum Number of Cars Per Class: 3
Critical Value of Test Statistic at .05 Significance Level = 3.84146

MEAN FUEL ECONOMIES rest statistic'!)
CLASS EPA Cert Calif Title 13 EPA-Calif
530014020 24.3 22.0 7.7
545035040 15.6 14.7 0.3
550044040 13.9 14.4 25.7
550045440 14.3 13.4 1.6
555045440 13.6 12.2 0.8
640025010 19.8 17.2 21.7
640030420 16.3 14.8 9.6
645035040 18.8 14.7 32.4
645036040 17.0 13.1 20.4

(1) Defined in Appendix II.


This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors

and grantees, and nonprofit organizations - as supplies permit - from
the Air Pollution Technical Information Center, Environmental Protec-
tion Agency, Research Triangle Park, North Carolina 27711, or from the
National Technical Information Service, 5285 Port Royal Road, Spring-
field, Virginia 22151.

This report was furnished to the Environmental Protection Agency by Aero-
space Corporation, El Segundo, California, in fulfillment of Contract No.
68-01-0417. The contents of this report are reproduced herein as received
from Aerospace Corporation. The opinions, findings, and conclusions ex-
pressed are those of the author and not necessarily those of the Environmen-
tal Protection Agency Mention of company or product names is not to be

considered as an endorsement by the Environmental Protection Agency.

Publication No. EPA-460/3-76-027

in


44C5
4405
4405
44C6
44C6
44C6
4406

1S
75
15
76
Te

76

tic
TIC
TIC
TI-c
1I-C
TI-C
Iv-C

Table I-{. California Title 13 Data Base (Continued)

A5C167H105631
ASC1ETH168452
A5A16TH206060
A6A887H233205
A6A8B7h233230
£6A887H233203
AGABBTIP226924

RNNNe ee

09.18
11.13
10.54
09.75
09.87
10.19
09.84

09.98
10.85
10.56
09.91
10.10
10.22
09.76

1-8

1€0.C6
10.53
10.36
10.01
10.35
10.17
09.86

SSSEs olll
LidiL oll.
22212 0000
TLLLo Olll
11110 oll
11110 olll
11110 OLln
0271 CARDS

304
304
304
304
304
304
360

4500
4500
4500
4500
4500
4500
4500

SNUNARNAN


ANALYSIS
OF PRODUCTION
CARS’
FUEL
ECONOMY

by
Dr. Ronald F. Janz
Mobile Systems Group
Aerospace Corporation
El Segundo, California 90245
Contract No. 68-01-0417

EPA Project Officer: J.D. Murrell

Prepared for

EPA-460/3-76-027

U.S. ENVIRONMENTAL PROTECTION AGENCY

Office of Air and Waste Management

Office of Mobile Source Air Pollution Control

Emission Control Technology Division
Ann Arbor, Michigan 48105

October 1976


APPENDIX II

FORMULAS FOR HARMONIC MEAN FUEL ECONOMY AND THE TEST
STATISTIC FOR EVALUATING DIFFERENCES IN FUEL ECONOMY

The following was extracted from Appendix III of the U.S. Environ-
mental Protection Agency report EPA 460/2-74-001.

I. 4 HARMONIC MEAN FUEL ECONOMY
HMFE = ——L— (1-1)
mpg
where

Zz
Hl

= number of cars per class
mpg; = miles per gallon for ith car ina class
u.2 TEST STATISTIC

It can be shown that the following quantity is distributed as a chi-

square witha level of confidence and one degree of freedom:

2
G= ( 1 ) 5 1 5 (IL-2)
TMpBy mpg,



Table I-3. California Title 13 Data Base Codes (Continued)

Manufacturer Division Model
AMC AMG 01 Gremlin
4 4 02 Pacer
03 Hornet
04 Hornet Wgn.
05 Matador

06 Matador Wgn.
07 Ambassador
08 Ambassador Wgn.

09 Javelin
Chrysler Chrysler 01 Cordoba
3 0 02 Newport

03 New Yorker
04 Imperial
05 Town & Country Wen.

Dodge 01 Dart
2 02 Aspen
03 Aspen Wen.
04 Coronet
05 Charger

06 Coronet Wen.
07 Charger S.E.
08 Monaco

09 Monaco Wen.

Plymouth OL Valiant (Scamp, Duster)
3 02 Volare
03 Volare Wen.
04 Satellite (1975 Fury)
05 Satellite (1975 Fury) Wgn.
06 Fury (1975 Gran Fury)
07 Fury (1975 Gran Fury) Wen.

I-41


It was the original intent of this study to compare data bases not only
on a carline basis, but also by manufacturer and fleet. This was not possible
because of the limited number of carline classes and models per class which
were available for analysis. For example, there were only two Pintos and
two Granadas representing Ford in the California Title {3 Data Base in car-
line classes which were common to the EPA Certification Test Data Base.
These four cars cannot realistically be used to represent the Ford Motor
Company.

Even though projected sales data were available by model, it was
not used to compute sales-weighted harmonic mean fuel economies for carline
classes. In addition to relating mean fuel economies to sales, sales weight-
ing is used to correct for differences in model (or class) mix, and it is clear
from Table 3-2 that rarely are the same models being compared in the two

data bases. Also, in many cases, only a single car represents a given model.


Table 3-3. Production Car Fuel Economy Study - Urban Results

Sales Weighted: No
Minimum Number of Cars Per Class: 3
Critical Value of Test Statistic at .05 Significance Level = 3.84146

MEAN FUEL ECONOMIES TEST statistic!)
CLASS EPA Cert Calif Title 13 EPA-Calif
530014020 17.2 15.4 8.8
545035040 14.5 10.6 1.3
550044040 9.2 7.8 35.0
550045440 10.3 9.5 2.3
555045440 9.9 8.8 2.6
640025010 14.6 12.4 17.9
640030420 11.5 10.8 5.7
645035040 13.0 10.5 49.9
645036040 14.3 9.7 14.0

(1) Defined in Appendix II.

3-5