LDTP 78-11
Technical Report
May 12, 1978
Tire Rolling Resistance Measurements at
Initial Inflation Pressures Of 45 PSIG and 26 PSIG
by
Richard N. Burgeson
NOTICE
Technical reports do not necessarily represent final EPA decisions
or positions. They are intended to present technical analysis of
issues using data which are currently available. The purpose in
the release of such reports is to facilitate the exchange of tech-
nical information and to inform the public of technical develop-
ments which may form the basis for a final EPA decision, position
or regulatory action.
Standards Development and Support Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Office of Air and Waste Management
U.S. Environmental Protection Agency
-------
I. Introduction
A recent EPA Technical Report [1] presents the results of a
program which relates tire rolling resistance measurements conduc-
ted on a Clayton twin small-roll dynamometer to those on a LABECO
single large-roll (48" diameter) dynamometer. The report extrapo-
lates the results obtained on the LABECO to the road by the appli-
cation of a curvature correction factor developed as a result of
tire testing on both a flat surface machine and a large (67"
diameter) roll dynamometer. This factor has been reported in the
technical literature [2]. In the EPA study, all tests were con-
ducted at 45 PSIG cold inflation pressure which is the typical tire
pressure used for emissions and fuel economy testing on the dyna-
mometer.
In order to determine the effect of tire pressure on rolling
resistance, data were collected on the same tires used in the above
study at a cold inflation pressure of 26 PSIG. These data were
then combined with the 45 PSIG data for statistical comparison.
II. Program Design
A total of 84 tests were conducted on 34 pairs of tires during
this study. The basic design of this study was similar to that
described in the reference [1] report. The following changes in
the test procedure of that report were made for this study:
1) All tests were conducted on a single large-roll dyna-
mometer (the same dynamometer used in the previous study).
2) The Federal Test Procedure (FTP) urban driving schedule
was driven prior to a 15-minute 50 MPH-steady-state tire rolling
resistance measurement period. The FTP was considered the tire
warm-up period.
3) Only two dynamometer horsepower settings were used,
10.5 HP for 14" and 15" tires and 7.4 HP for 13" tires. These
dynamometer settings were determined in the same manner as those
in reference [1].
4) The initial cold inflation pressure for all tires tested
was 26 PSIG.
All other aspects of this study were identical to those described
in the reference [1] report. A complete description of each tire
tested (tires of both studies) may be found in Appendix A.
-------
-2-
III. Analysis
The method used to determine the tire rolling resistance,
F , and the amount of power absorbed by the tire at 50 mph, PATM>
was to monitor both the power transmitted by the vehicle and the
power received by the dynamometer. The difference was considered
the power absorbed by the tire. From this absorbed power, the tire
rolling resistance was derived. For a complete derivation of the
analysis process refer to Appendix B.
The tire rolling resistance and power absorption data gener-
ated in this study were then combined with the corresponding data
generated during the previous EPA study. The combined data were
then corrected for roll curvature using the following equation:
Curvature Corrected Rolling Resistance = F x C
RR UK.
where
F = Tire rolling resistance,
KK
rL -1/2
= roll curvature correction factor = (1 + — — )
1J K R
r = tire load radius, and
LI
R = dynamometer roll radius.
The curvature corrected and the rolling resistance and tire
power absorption data were then statistically compared. These and
the uncorrected data are presented in Appendix C. The percent
difference in mean tire rolling resistance values due to inflation
pressure was computed according to the following equation:
Mean F at 26 PSI - Mean F_D at 45 PSI
t RR .. ,cRR T ] x 100%
Mean FDO at 45 PSI J
KK
An analysis of variance performed on all of the 26 PSI and 45
PSI data indicated that tire pressure has a significant effect on
tire rolling resistance. It was found that, in general, the tire
rolling resistance decreased 2.21% for each 1 PSI increase. In
order to determine if the percent difference was a function of tire
type, the analysis was repeated on the data for the radials, bias
belted, and bias ply tires of the sample. It was found that in
each case, the tire pressure had a significant effect on the
rolling resistance with each 1 PSI increase for each tire type.
-------
-3-
Table 1
Effects of Inflation Pressure on
Rolling Resistance by Tire Type
Tire Type Decrease in Rolling Resistance
Radlals 2.26%/(PSI increase)
Bias Belted 2.51%/(PSI increase)
Bias 1.10%/(PSI increase)
The effects of increased inflation pressure were investigated
further by analyzing the data with respect to both tire size and
type. Table 2 presents these results.
Table 2
Effects of Inflation Pressure on
Rolling Resistance by Tire Type and Size
Tire Size and Type Decrease in Rolling Resistance
13" Radial 1.99%/(PSI increase)
13" Bias Belted Insufficient Data
13" Bias 0.54%/(PSI increase)
14" Radial 1.77%/(PSI increase)
14" Bias Belted 2.60%/(PSI increase)
14" Bias Insufficient Data
15" Radial 2.53%/(PSI increase)
15" Bias Belted 3.88%/(PSI increase)
15" Bias 2.15%/(PSI increase)
The above analysis detected a significant effect on rolling
resistance due to inflation pressure for all of the above cases
except for 13" bias ply tires. It should be noted from Table 2
that 14" and 15" bias belted tires seem to be the most sensitive to
tire pressure changes. This may be caused by the reduction in
sidewall deflection as the tire pressure is increased.
Scatter plots of the curvature corrected rolling resistance,
F , and the normalized power absorbed at 50 MPH, PATN> as a func-
tion of tire pressure are presented in Appendix D.
Conclusions/Recommendations
' The conclusions of this study are:
-------
-4-
1) For the tires tested, tire rolling resistance decreases
2.21% per 1 PSI increase in inflation pressure (assuming a linear
effect between 26 and 45 PSIG). It is estimated that a 10%
reduction in rolling resistance produces a 2% increase in fuel
economy [3]. This translates to approximately a 0.4% increase in
fuel economy per 1 PSI inflation pressure increase.
2) The magnitude of the effect of inflation pressure on tire
rolling resistance is dependent upon tire size and type. In
general, the decrease in rolling resistance per PSI inflation
pressure increase is 2.26%, 2.51% and 1.10% for the radial, bias
belted and bias ply tires of this sample, respectively.
3) The greatest fuel economy improvement may be obtained by
increasing the inflation pressure of bias belted tires.
The data contained in this report indicate that tire infla-
tion pressure plays an important role in a particular tire's
rolling resistance and therefore a vehicle's fuel economy. The
trend thus far on the part of the automotive industry has been to
request lower rolling resistance tires from the tire industry and
to increase tire inflation pressures in order to comply with the
fuel economy standards. Although an automotive manufacturer can
recommend a high inflation pressure, there may have been insuffi-
cient incentive to make sure this pressure is maintained by the
vehicle owner or new car dealer. Since the Government's concerns
are with fuel consumption, perhaps a public awareness campaign
should be launched stressing the effects of tire rolling resistance
and the importance of proper tire pressure with respect to fuel
economy. This campaign could be sponsored by the automotive
manufacturers, an automotive association (MVMA, SAE, etc.), or by
the government (EPA, DOT, DOE, etc.). The effectiveness of the
campaign could be evaluated through the EPA Emission Factor
Program.
In conjunction with the public awareness campaign, EPA
should conduct a survey of new car dealerships to determine if
dealers are routinely setting new car tire pressures to the manu-
facturer's specifications. If not, lower, more representative tire
pressures should be required when determining dynamometer road load
settings.
Perhaps all tires on new light-duty vehicles should come
equipped with tire pressure regulating/warning systems to alert
the vehicle owner to under or over inflated tire pressures. This
would aid the vehicle owner in the maintenance of the recommended
tire pressure.
-------
References
1. Burgeson, R.N., "Tire-Dynamometer Roll Effects", EPA Technical
Report LDTP-77-4, March 1978.
2. Schuring,D.J., "Rolling Resistance of Tires Measured Under Tran-
sient and Equilibrium Conditions on Calspan's Tire Research
Facility," DOT-OST-76-9, March 1976.
3. Thompson, G.D. and Myriam Torres, "Variations in Tire Rolling
Resistance", EPA Technical Support Report for Regulatory
Action, LDTP-77-05, October 1977.
4. Elliot, D.R.; Klamp, W.K.; and Kraeiner, W.E., "Passenger Tire
Power Consumption," Society of Automotive Engineers, SAE
710575.
5. Floyd, C.W., "Power Loss Testing of Passenger Tires," Society
of Automotive Engineers, SAE 710576.
6. Crum, W.B., "Road and Dynamometer Tire Power Dissipation,"
Society of Automotive Engineers, SAE 750955.
7. Schuring, D.J., "The Energy Loss of Tires on Twin Rolls, Drum,
and Flat Roadway - A Uniform Approach," Society of Automotive
Engineers, SAE 770875.
8. Clark, S.K.; Dodge, R.N.; Banter, R.J.; and Luchini, J.R.;
"Rolling Resistance of Pneumatic Tires," University of
Michigan Report DOT-TSC-74-2; Prepared for The Department of
Transportation, Transportation Systems Center, Cambridge,
Mass., July 1974.
9. Curtis, W.W., "Low Power Loss Tires," Society of Automotive
Engineers, SAE 690108.
10. Clark, S.K., "Rolling Resistance Forces in Pneumatic Tires,"
University of Michigan Report DOT-TSC-76-1; Prepared for The
Department of Transportation, Transportation Systems Center,
Cambridge, Mass., January 1976.
11. Thompson, G.D., "Light-Duty Vehicle Road Load Determination,"
EPA Technical Support Report for Regulatory Action, LDTP-76-03,
December 1976.
-------
APPENDIX A
Two Study Tire Description
-------
A-l
Tire Description
ID Number
010
020
050
060
070
080
090
100
110
12A
12B
13A
13B
15A
16A
16B
180
200
210
220
230
240
250
260
270
290
300
310
320
330
340
350
360
370
380
390
400
410
420
(both
Manufacturer
Goodyear
Goodyear
Goodyear
Goodyear
Goodyear
Goodyear
Goodyear
Goodyear
Goodyear
B.F. Goodrich
B.F. Goodrich
B.F. Goodrich
B.F. Goodrich
B.F. Goodrich
B.F. Goodrich
B.F. Goodrich
Firestone
Goodyear
Uniroyal
Goodyear
General
Uniroyal
Goodyear
Uniroyal
Firestone
Firestone
Uniroyal
Firestone
Goodyear
Uniroyal
Firestone
Uniroyal
Goodyear
Firestone
Uniroyal
Firestone
Uniroyal
B.F. Goodrich
B.F. Goodrich
studies combi
Size
BR 70X13
BR 70X-13
HR 78X14
H 78X15
HR 78X15
HR 70X15
HR 78X15
B 78X13
H 78X14
HR 78X15
HR 78X15
H 78X15
H 78X15
HR 78X15
HR 70X15
HR 70X15
GR 78X15
HR 78X15
GR 78X15
GR 78X15
GR 78X15
LR 78X15
1 ER 78X14
FR 78X14
FR 78X14
HR 78X15
ER 78X14
ER 78X14
E 78X14
E 78X14
E 78X14
B 78X13
BR 78X13
BR 78X13
BR 78X13
B 78X13
HR 78X15
B 78X13
GR 78X15
Model
Polyglass Radial WT
Polyglass Radial
Polyglass Radial WT
Custom Power Cushion Polyglass
Polyglass Radial
Polyglass Radial WT
Custom Polysteel Radial
Cushion Belt Polyglass
Cushion Belt Polyglass
Silvertown Steel Radial
Silvertown Steel Radial
Custom Long Miler
Custom Long Miler
Silvertown Belted
Silvertown Lifesaver XL-100
Silvertown Lifesaver XL-100
Steel Belted Radial
Steel Belted Radial Custom Tread
Steel Belted Radial PR6
Steel Belted Radial Custom Tread
Dual Steel II Radial
Steel Belted Radial PR6
Steel Belted Radial Custom Tread
Steel Belted Radial
Steel Belted Radial
Steel Belted Radial
Steel Belted Radial
Steel Belted Radial
Custom Power Belted Cushioned Polyglass
Fastrak Belted
Sup-R-Belted Deluxe Champion
Fastrak Belted
Steel Belted Radial
Steel Belted Radial
Steel Belted Radial
Deluxe Champion
Steel Belted Radial
Silvertown Bias
Lifesaver 78 Steel Belted Radial
-------
APPENDIX B
Methodology for Determining Tire Rolling Resistance
-------
B-l
Methodology Utilized to Determine Tire Rolling Resistance
The power absorbed by the tire was computed each second of
data collected according to the following equations:
P=P -P -P 1
AT engine abs. diff. bearing losses dyno
= TengWE - TdiffWE ' TLCWD ' VWD 2
(T - T )W - (T + T )W
Ueng diff' E- ULC BI/ D
where
P = the power absorbed by the tire at the test speed
A J.
•p = torque from the engine/transmission (measured by the
etl8 driveshaft torque sensor)
T = torque required to revolve the rear axle and. associ-
ated bearings and gearing which make up the differ-
ential. Note: This quantity includes any effects
due to brake drag.
T = total torque measured by the dynamometer load cell
IjC
T = torque due to bearing and frictional losses in the
dynamometer
W and W = the angular velocities of the vehicle driveshaft
and dynamometer roll, respectively.
From each P the rolling force was then derived as follows:
A JL
PAT = TTWT 4
where T is the torque at the tire/roll interface and W is the
angular velocity of the tire. However, T can be defined as the
product of a force and a lever arm as follows:
TT = FR x r 5
where F is the rolling force of the tire and r is the tire
radius. Substituting equation 5 into 4 yields:
PAT - (FR x r) WT 6
-------
B-2
Since the angular velocity W can be represented as a ratio of
the linear velocity, V, and the radius of the tire, r, a sub-
stitution for W in equation 6 produces:
(F x r)V
p = _£ - 1 _ v ?
AT r *RVT '
the linear velocity V is in actuality the ground o test surface
velocity. However, with all vehicle tests on dynamometers,
a certain amount of slip between the tire and the dynamometer roll
occurs. Therefore, the vehicle linear velocity, the one parameter
common to both dynamometers, rather than the dynamometer-roll
linear velocity was utilized for this analysis. Therefore, F can
be expressed as;
PAT
where V is the vehicle speed.
Of all the parameters affecting tire power absorption, the
vertical load on the tire has yet to be discussed. In general,
tire power absorption is directly proportional to the load upon
it. As the vertical load increases, the tire power absorption
also increases. Therefore, all the above computations are a
function of the vertical load under which a particular set of
tires was tested. The vertical load used for this experiment was
arrived at by weighing the rear portion of each test vehicle with a
full tank of fuel and a driver. Fuel was added to each test vehicle
at the completion of every second test in order to maintain as
constant a vertical load as possible. However, the vertical load
of the two test vehicles differed, therefore, making direct
tire rolling force, FR, data comparsions difficult. By calculating
the ratio of FR to the test vertical load, F , all tire test
results cold then be directly compared. This is expressed in the
equation below:
F = — 9
RR FZT
However, statements concerning the power absorbed at 50 mph ,
PAT, for all the data still could not be made. Since the tire
rolling force, FR> ±s nearly linear with vertical load, [2] [3] [4]
estimates of the power absorbed at 50 mph can be obtained using
a form of equation 9. Using the rolling resistance values, F ,
previously obtained, a standard vertical load was chosen and the
power absorbed at 50 mph was predicted. The equations presented
below outline this process:
-------
B-3
FRN =FRXFZN 10
PATN ' FRN X 5°
where F is as defined in equation 9 and
RR
F = normalized F
RN R
F = 2.985 x 10 Ibs.
PATN = normalized PAT
The standard vertical load was chosen to be the rear weight of the
Ford stationwagon used to test 14" and 15" tires.
-------
APPENDIX C
Normalized Test Results by Tire Identification Number
-------
Table C-l
Normalized Test Results by Tire Identification Number
ROLL CURVATURE CORRECTED
TIRE
ID
010
010
020
050
n50
OSO
060
060
070
070
000
080
090
090
090
090
090
itQO
090
100
100
100
110
110
l?A
12A
1?B
12B
13A
13A
13A
13A
13A
13A
13A
13B
13B
ISA
15A
15A
15 A
15A
15A
IRO
. 1HO
200
-------
Table C-l continued
ROLL CURVATURE CORRECTED
ROLLING
TIRE RESISTANCE
ID (LB/K-LB)
240
250
250
260
260
270
270
290
300
300
120
120
340
340
350
350
360
360
370
370
370
380
3fiO
390
390
390
400
400
4)0
410
420
420
020
020
020
060
060
070
080
080
126
128
12B
13A
13A
138
16A
168
168
180
200
200
210
220
220
230
230
240
240
250
15.415
14.101
9.515
12.326
11.P94
12.714
12.167
lb.820
10.934
10.575
15.193
16.013
17.755
18.436
16.508
13.010
11.624
12,497
10.905
14.320
11.491
14.660
11.872
19.736
14.737
1 « . 265
13.407
14.324
14.993
13.630
13.520
12.874
6.008
12.160
14.681
9.783
7.962
5.405
8.145
11.409
10.997
9.919
9.836
8.329
15.967
11.463
11.475
11.427
11.875
11.628
4.907
7.279
6.335
8.235
5.582
10.136
6.404
10.468
7.149
8.327
ROLLING ABSORBED ROLLING ROLLING ABSORBED
FORCE AT 50 MPH RESISTANCE FORCE AT 50 MPH TIRE TYPE
(NT)
204.678
187.236
126.338
163.665
157.922
168.821
161.547
210.051
145.175
140.417
201.735
212.615
235.750
244.789
219.189
172.747
154.344
165.930
144.789
190.137
152.572
194.661
157.635
262.054
195.683
242.520
178.015
190.187
199.080
181.648
179.521
170.945
79.770
161.452
194.933
129.896
105.717
71.770
108.150
151.477
146.005
131.699
130.598
110.581
212.003
152.202<
152.359
151.719
157.663
154.385
65.146
96.650
84.118
109.334
74.114
134.572
85.028
138.981
94.924
110.563
(WATTS) (LB/K-LB)
4576.137
4186.172
2824.636
3659.167
3530.766
3774.443
3611.833
4696.266
3245.785
3139.397
4510.324
4753.582
5270.828
5472.922
4900.563
3862.220
3450.779
3709.808
3237.163
4251.035
3411.170
4352.172
3524.353
5858.930
4375.016
5422.203
3980.013
4252.152
4450.977
4061.240
4013.690
3821.945
1782.857
3608.446
4358.250
2903.176
2362.775
1604.059
2417.152
3385.511
3263.212
2943.473
2918.865
2471.485
4738.266
3401.715
3405.224
3390.920
3523.768
3450.505
1456.013
2160.127
1880.037
2443.615
1656.448
3007.684
1900.376
3106.225
2121.551
2471.083
12.P70
11.591
7.821
9.984
9.634
10.425
9.977
12.672
8.988
8.693
12.306
12.971
14.382
14.933
13.487
10.629
9,555
10.273
8.964
11.771
9.446
12.036
9.747
16.164
12.070
14.959
10.726
11.459
12.279
11.204
10.870
10.351
4.927
9.971
12.053
7.797
6.346
4.324
6.516
9.127
8.798
7.935
7.869
6.638
12,726
9.113
9.088
9.039
9.393
9.349
3.931
5.830
5.093
6.621
4.488
8.139
5,142
8.333
5.691
6.778
(NT)
162.924
153.908
103.850
132.569
127.917
138.433
132.469
KP.251
119.334
115.423
163.405
172.219
190.957
198.279
179.077
141.134
126.871
136.394
119.017
156.293
125.414
159.817
129.418
214.622
160.264
198.624
142.412
152.150
1*3.047
148.770
144.335
137.440
65.411
132.391
160.040
103.527
84.256
57.416
86.5?0
121.182
116.804
105.359
104.478
89.133
168.966
121,001
120.668
120.010
124.711
124.126
52.182
77.417
67.631
87.905
59.588
108.061
68.277
110.629
75.559
89.998
(WATTS) SIZE CODE
3642.605
3441.033
2321.851
2963.925
2859.920
3095.043
2961.703
3761.709
2668.035
2580.584
3653.363
3850.401
4269.367
4433.066
4003.759
3155.434
2836.540
3049.462
2660.948
3494.351
2803.182
3573.133
2893.494
4798.461
3583.138
4440.781
3184.010
3401.722
3645.350
3326.156
3227.007
3072.844
1461.943
2958.926
3578.123
2313. R31
1883.131
1283.247
1933.722
2708.409
2610.569
2354.778
2335.092
1969.773
3776.397
2704.364
2696.937
2682.218
2787.301
2774.206
1166.266
1730.261
1511.550
1964.666
1331.784
2415.170
1526.002
2472.555
1688.754
2011.461
15
14
14
14
14
14
14
15
14
14
14
14
14
14
13
13
13
13
13
13
13
13
13
13
13
13
15
15
13
13
15
15
13
13
13
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
14
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
4.
4.
4.
4.
5.
5.
3.
3.
3.
3.
3.
3.
3.
5.
5.
5.
3.
3.
5.
5.
3.
3.
3.
3.
3.
4.
4.
3.
3.
3.
3.
3.
3.
5.
5.
5.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
TEST
PRESS.
(PSI)
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
26.0
45.0
45.0
26.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
. 45.0
45.0
45.0
-------
Table C-l (concluded)
ROLL CURVATURE CORRECTED
ROLLING
TIRE RESISTANCE
IP (LB/K-LB)
250
250
250
260
260
270
270
290
300
100
300
310
M{\
u
no
11 0
»,( 4 V/
320
320
3?0
*J C \J
330
330
330
340
340
340
150
-.' -J \J
350
370
370
400
" U V
u i n
*T I V
4]0
41 0
~ 1 •*
4?0
~T C. V
420
11.978
7.852
8.054
9.317
7.737
8.598
8.977
10.650
9.846
12.584
8.671
12.081
7.582
6.074
1 1 . 143
9.453
9.049
9. 143
14.467
11.732
10.645
12.026
1 1.630
10.880
15.710
11.524
tt.892
10.681
10.808
18.624
12.388
13.689
7.410
6.654
ROLLING
FORCE
INT).
159.039
104.248
106.932
123.708
102.725
11^.163
119.187
141.404
130.734
167.087
115.121
160.4Q3
100.672
80.645
147.946
125.506
120.146
121.398
192.077
155.767
141.334
159.679
154.410
144.461
208.586
153.007
1 18.062
141.815
143.499
247.276
164.479
181 .753
98.388
88.346
ABSORBED ROLLING
AT 50 MPH RESISTANCE
(WATTS) (LB/K-LB)
3554.52?
2329.941
2389.930
2764.874
2295.904
2551.543
2663.330
3160.379
2921.905
3734.394
2572.954
3585.007
2250.019
1802.416
3306.593
2805.059
2685.263
2713.245
4292.92?
3481.39?
3158.815
3568.826
3451.063
3228.703
4661.898
3419.715
2638.676
3169.557
3207,203
5526.621
3676.104
4062.173
2198.972
1974.533
9.750
6.392
6.556
7.537
6.259
6.973
7.280
8.531
7.995
10.218
7.041
9.8?2
6. 164
4.938
9.059
7.657
7.330
7.406
11.733
9.515
8.633
9.729
9.409
8.802
12.851
9.427
7.300
8.769
8.646
15.253
10.146
11.211
5.950
5.343
ROLLING ABSORBED
FORCE AT 50 MPH TIRE TYPE
(NT)
129.458
84.858
87.043
100.080
83.105
92.586
96.661
113.265
106.1=56
115.675
93.478
130.408
81.846
65.564
120.280
101.6f,0
97.318
98.332
155.774
126.327
114.622
129.180
124.918
116.869
170. 6?3
125.160
96.929
116.430
114.799
202.519
134.708
148.856
79.006
70.942
(WATTS) SIZE CODE
2893.381
1896.573
1945.403
2236.783
1857.386
2069.301
2160.366
2511.463
2172.587
3032.328
2089.239
2914.611
1829.265
1465.364
2688.260
2272.098
2175.063
2197.729
3481.560
2023.409
2561.799
2H87.180
2791.910
2612.021
3813.433
2797.327
2166.353
2602.206
2565.762
4526.301
3010.729
3326.920
1765.774
1585*550
14
14
14
14
14
14
14
15
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
13
13
13
13
15
13
13
13
15
15
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
3.
4.
4.
4.
4.
4.
4.
4.
4.
4.
5.
5.
3.
3.
3.
5.
5.
5.
3.
3.
TEST
PRESS.
(PSI)
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
Tire Type Code
3 = Radial
4 = Bias Belted
5 = Bias
-------
APPENDIX D
Plots of PATM and F as a Function
A.J. W K.IX
of Inflation Pressure
-------
o.
rt
3
4333.3
3777.8
322?.?
4
9
6
8
3
5
5
3
6
5
4
7
4
4
4
3
u
00
c
2111.1
1555.
3
3
S
1000.0
?6.000 45.000
COLD INFLATION PRESSURE(PSI)
-------
a
4333.3
O
l-l
cr
re
o.
o
1 x
3777.H
CD
I
P-.
T3
0)
N
?66b.7
3
2
5
4
3
4
5
4
7
4
4
4
2
4
4
t) C
H1 3
H P-
H- O
it 3
00
C
2111.1
15S5.6
1000.0
26.000
COLO INFLATION
45.000
PRESSURE (PSI)
-------
-------
a.
13
33
4333.3
•O
01
.0
1-1
O
ITS
.0
H- CO H-
& OQ
« tU C
3777.8
2
3
>fl
1 C
3
M O
(D 3
a
i
3
-t-h
H*
[U
2666.7
2111.1
1555.6 +
1000.0
26..000 45.000
COLD TNFLATION PRESSURE(PSI)
-------
SI E:13 CASES=TYPE:3
N= 15 OUT OF 15 6.PATMC VS. 9.PSI
PATNC
6000.0 *
Corrected for Roll Curvature
4868.9
T)
O
S
to
4333.3
cr
CO
O
cr
o.
B
1
3777.8
-------
SCATTER PLOT <1A> SI EM4 CflSES=TYP£:3
N= 2* OUT OF 26 fr.PATMC VS. 9.PSI
PATNC
6000.0 +
Corrected for Roll Curvature
4888.9
3
O
p-l
4333.3
3777.8
3222.2
2666.7
2111.1
1555.6
cr
ro
D.
SB
. a
a. ^
H- C
U 3
H- O
1 3
"1
H-
00
1000.0
COLD INFLATION PRESSURE(PSI)
-------
SCATTER PLOT <15> SI E:15
N= 56 OUT OF 56
PATIMC
6000.0 +
5444.4
4888.9
rt
H H-
H- O
1 3
It
in O
i-n
m
c
o
I
2111.1
1555.6
1000.0
26.000 45.000
COLD INFLATION PRESSURE(PSI)
-------
; (7,64)
SCATTER PLOT <13> SI E:13 CASES=TYPE :
N= 3 OUT OF 3 6.P4TNC VS. 9.PST
PATNC
600.0.0 *
5444.4
4888.9
^333.3
Corrected for Roll Curvature
CL
[U
^777.8
co c
n> 3
M O
o
I
0)
3222.2
D. O
g
ro
MM
3
3666.7
2111.1
1555.6
1000.0
36.000 45.000
COLD TNPLaTION PRESSURE(PSI)
-------
SCATTER PLOT <14> SI E:14 CASES=TYPE:81ASRE
N= 15 OUT OF 15 ft.PATNC VS. 9.PSI
PATNC
6000.0 *
5444.4
4888.9
Corrected for Roll Curvature
tr
CO
a.
« "333.3
Mi Ln
O O
CD
•a
01
3
o
OH
3777.8
3322.2
o>
E7) CO
(n
•fl
ts c
CD 3
I-1 O
-ft rr
n> H-
o. o
09
c
1-1
ID
O
I
2666.7
2111.1
1555.6
1000.0
26.000 45.000
COLD INFLATION PRESSURE(PSI)
-------
SCATTER PLOT <15> SI F:15 CASE5=TYPE:BIAS«E
N= 10 OUT OF 10 6.PATMC VS. c
PATNC
6000.0 *
Corrected for Roll Curvature
5444.4
4888.9
-2 4333.3
o
i-t
o-
•a
cu
3777.8
ff§
E. o
O
I
3322.3
ro M
3 ?666.7
2111.1
1555.6
1000.0
26.000 45.000
COLO TNKLATION PRESSURE(PSI)
-------
SCATTER PLOT <13> SI EH3 CASFS=TYPE:BI AS
N= 1? OUT OF 12 6.PATMC VS. 9.PSI
PATNC
6000.0 *
5444.4
Corrected for Roll Curvature
4888.9
4333.3
cr
III
a.
S 3777.8
0!
a en
3 322?.? »
H H-
H- O
i-< 3
(D
CD O
2666.7
2111.1
1555.6
(D
K
01
C
1000.0
36.000 45.000
COLD INFLATION P«FSSURt~
-------
SCATTER PLOT <)S> SI EU5 CASF.S = TYPE :RT AS
N= 12 OUT OF 12 6.PAT"iC VS.
PATNC
6000.0 +
Corrected for Roll Curvature
48H8.9
4333.3
3777.8
3222.2
2666.7
2111.1
1555.6
IS
O
O
l-l
a-
o
o.
"0 C
H- 3
»< O
ft
H H-
H- O
11 3
ID
CO O
3
t-tl
H"
U
00
c
rl
o
i
1000.0
26.000 45.000
COLD INFLATION PRESSURE(PSI)
-------
SCATTER PLOT
N= 149 OUT OF" 149 4.Fa,
-------
CD O
0) 3
00
c
g> 11.2^7
9.2000
3
5
5
5
7
3
7
n
ro
CO
ID
c
7.1333 *
5.0667 +
3.0000
26.000 45.000
COLO INFLATION PRESSURE(PSI)
-------
c
H-1 3
rr o
O
H 3
00
C
1-1
ro
o
I
5 11.207
9.2000
i-t
(0
01
7.1333
^.0667
3.0000
26.000 45.000
COLD INFLATION! PRESSURE (PSI)
-------
SCATTER PLOT CftSES=TYPE:BIAS
M= 3«* OUT OK 24 4.FRRC Vs. 9.PST
FHRC
21.600 *
19.533
17.467
15.400
Corrected for Roll Curvature
Hi 3
O O
11 ro
2
2
I-1 C
>< 3
oo
c
i-t O
ro -3
00
c
f
11.267
9.2000
7.1333 «
5.0667 »
3.0000 *
26.000 45.000
COLD INFLATION PRESSURE(PSI)
-------
SCATTER RYSTRATA VAP=a;9 CASES=Vs:3 STRAT=V7 INTFPVAL=<3.0.21.6)i (7,64)>
SCATTER PLOT <13> SI E:13 CASES=TrpE:3
M= IS OUT OF 15 4.FRRC VS« 9.PS!
FRRC
21.600 »
19.533 »
17.467 *
15.400 *
Corrected for Roll Curvature
3
00
i?
i 13.333 *
m
H- C
O 3
H' O
D
I
eo
e
II 3
TO
01 O
f-h
M
3
Ml
M
»
rt
H-
O
9.2000 *
7.1333 *
5.0667 +
3.0000
26.onn 45.000
COLO INFLATION PRESSURE(PSI)
-------
SCATTER PLOT <14> SI F.:14 CASFS=TYPE:3
N= 26 OUT OF 26 4.FRRC VS. 9.PST
FRRC
21.600 *
Corrected for Roll Curvature
19.533
17.467
15.^00
13.3J3
» OJ
03
a. TI
H- C
[0 3
H" O
rt
H H-
1-^ O
I 3
ro
CO O
00
C
S 11.267
a:
ao
c
I
os 9.2000
7.1333
S.0667
3.0000
26.000 *5.000
COLO INFLATION PRESSURE(PSI)
-------
SCATTER PLOT <15> 51 E:15
N= 56 OUT OF 56
FRRC
21.600 »
CASES=TYPE:3
4.FRRC VS. 9.PST
Corrected for Roll Curvature
19.533
17.467
15.400
i-n 01
O D
3 13.333
a. TI
H- C
01 3
H H-
H- O
n a
oo
c
1-1
re
00
c
f
3
2
3
3
4
2
3
3
4
7.1333
5.0667
3.0000
?6.000 45.000
COLD INFLATION PRESSURE(PSI)
-------
SI E:13 CASES=TYPE :BI ASBE
N= 3 OUT OF 3 4.FRRC VS. 9.PSI
FRRC
31.600 *
19.533
17.467
Corrected for Roll Curvature
pa
j
i
15.4UO
« 13.333
3
TO
so
n>
o it
ri 01
3
•-- o
Cd CD
H-
(B (fc
O
I
to
O
3 11.P&7
a!.
oo
c
H- O
1-1 H>
It
en M
3
f
9.?000
7.1333
5.0667
3.0000
36.00" 45.000
COLD INFLATION PRESSURE(PSI)
-------
SCATTER PLOT <14> SI E:14 CASES=1YPE:BIAS«E
N= 1!3 OUT OF 15 4.FRRC Vs. 9.PST
FRRC
21.600 »
19.533
17.467
15.400
Corrected for Roll Curavature
po
o
3
00
to
O n
n 0)
a
P- O
13.333
(B Oi
w
fD 3
i-1 n
rt rr
(0 H-
-------
SCATTER PLOT <15> M F:15 CASES=TYPE:
N= 10 OUT OF 10 4.FRRC VS. 9.PST
F«RC
21.600 *
Corrected for Roll Curvature
19.533
17.467
15.400
13.3J3
11.267
3
00
co c
n> 3
I-1 O
o
I
9.2000
7.1333 »
5.06^7 »
3.0000 *
26.000 45.000
COLO INFLATION P«ESSU«E(PSI)
-------
SI E:13 CASES=TYPEtBJflS
N= 1^ OUT OF 12 4.FRRC \/S. 9.PST
FRRC
21.600 »
Corrected for Roll Curvature
19.533
17.467
15.400
13.333
en
t-h rt
O B
H 3
O
i- re
CO
r 0)
00
C
00
C
11.267
H O
H- 3
i-l
TO O
9.2000
7.1333
5.0667 *
3.0000 *
26.000 45.000
COLD INFLATION PRFSSURE(PSI)
-------
SCATTER PLOT <15> SI E:15 CASES = TYPF. :BT AS
*J= 12 OUT OF 12 4.FRRC V/S. 9.PST
FRRC
21.600 »
Corrected for Roll Curvature
19.533
17.467
H
H-
i-l
to
J
I
15.400
13.333
o
00
%
CO
H-
CO
>1 3
o
I— (0
Ln
: pi
CO
03
01
« 11.267
00
c
Q.POOO
7.1333
5.0667
3.0000
26.000 45.000
COLD INFLATION PRfSSURE(PSI)
------- |