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Code of Federal Regulations Title 40. Protection of Environment § 40.86.529–98 Road load force and inertia weight determination

Current as of January 02, 2025 | Updated by Findlaw Staff

(a)(1) Road load as a function of speed is given by the following equation:

F = A + CV2

(2) The values for coefficients A and C and the test inertia are given in Figure F98–9 of this section. Velocity V is in km/h and force (F) is in newtons. The forces given by the equation in paragraph (a)(1) of this section shall be simulated to the best ability of the equipment being used.

(b) The inertia given in Figure F98–9 shall be used. Motorcycles with loaded vehicle mass outside these limits shall be tested at an equivalent inertial mass and road load force specified by the Administrator. Figure F98–9 follows:

Figure F98-9

Force coefficients

70 to 60 km/h coastdown calibration times

Allowable

tolerance

Force

Loaded

Equivalent

C

at 65

Target

Longest

Shortest

vehicle

inertial

(nt/(km/

km/h

time

time

time

mass (kg)

mass (kg)

A (nt)

h)2)

(nt)

(sec)

(sec)

(sec)

95-105

100

0.0

.0224

94.8

2.95

3.1

2.8

106-115

110

0.82

.0227

96.8

3.18

3.3

3.0

116-125

120

1.70

.0230

98.8

3.39

3.6

3.2

126-135

130

2.57

.0233

100.9

3.60

3.8

3.4

136-145

140

3.44

.0235

102.9

3.80

4.0

3.6

146-155

150

4.32

.0238

104.9

3.99

4.2

3.8

156-165

160

5.19

.0241

107.0

4.10

4.4

4.0

166-175

170

6.06

.0244

109.0

4.36

4.6

4.2

176-185

180

6.94

.0246

111.0

4.53

4.7

4.3

186-195

190

7.81

.0249

113.1

4.69

4.9

4.5

196-205

200

8.69

.0252

115.1

4.85

5.1

4.6

206-215

210

9.56

.0255

117.1

5.00

5.2

4.8

216-225

220

10.43

.0257

119.2

5.15

5.4

4.9

226-235

230

11.31

.0260

121.2

5.30

5.5

5.1

236-245

240

12.18

.0263

123.2

5.43

5.7

5.2

246-255

250

13.06

.0266

125.3

5.57

5.8

5.4

256-265

260

13.93

.0268

127.3

5.70

5.9

5.5

266-275

270

14.80

.0271

129.3

5.82

6.1

5.6

276-285

280

15.68

.0274

131.4

5.95

6.2

5.7

286-295

290

16.55

.0277

133.4

6.06

6.3

5.8

296-305

300

17.43

.0279

135.4

6.18

6.4

6.0

306-315

310

18.30

.0282

137.5

6.29

6.5

6.1

316-325

320

19.17

.0285

139.5

6.40

6.6

6.2

326-335

330

20.05

.0288

141.6

6.50

6.7

6.3

336-345

340

20.92

.0290

143.6

6.60

6.8

6.4

346-355

350

21.80

.0293

145.6

6.70

6.9

6.5

356-365

360

22.67

.0296

147.7

6.80

7.0

6.6

366-375

370

23.54

.0299

149.7

6.89

7.1

6.7

376-385

380

24.42

.0301

151.7

6.98

7.2

6.8

386-395

390

25.29

.0304

153.8

7.07

7.3

6.9

396-405

400

26.17

.0307

155.8

7.16

7.4

6.9

406-415

410

27.04

.0310

157.8

7.24

7.5

7.0

416-425

420

27.91

.0312

159.9

7.33

7.6

7.1

426-435

430

28.79

.0315

161.9

7.41

7.6

7.2

436-445

440

29.66

.0317

163.7

7.49

7.7

7.3

446-455

450

30.54

.0318

164.9

7.61

7.8

7.4

456-465

460

31.41

.0319

166.0

7.73

8.0

7.5

466-475

470

32.28

.0319

167.1

7.84

8.1

7.6

476-485

480

33.16

.0320

168.3

7.95

8.2

7.7

486-495

490

34.03

.0320

169.4

8.06

8.3

7.8

496-505

500

34.90

.0321

170.5

8.17

8.4

7.9

506-515

510

35.78

.0322

171.7

8.28

8.5

8.0

516-525

520

36.65

.0322

172.8

8.39

8.6

8.2

526-535

530

37.53

.0323

173.9

8.49

8.7

8.3

536-545

540

38.40

.0323

175.1

8.60

8.8

8.4

546-555

550

39.27

.0324

176.2

8.70

9.0

8.5

556-565

560

40.15

.0325

177.3

8.80

9.1

8.6

566-575

570

41.02

.0325

178.5

8.90

9.2

8.7

576-585

580

41.90

.0326

179.6

9.00

9.3

8.8

586-595

590

42.77

.0327

180.8

9.10

9.4

8.9

596-605

600

43.64

.0327

181.9

9.19

9.5

8.9

606-615

610

44.52

.0328

183.0

9.29

9.5

9.0

616-625

620

45.39

.0328

184.2

9.38

9.6

9.1

626-635

630

46.27

.0329

185.3

9.47

9.7

9.2

636-645

640

47.14

.0330

186.4

9.56

9.8

9.3

646-655

650

48.01

.0330

187.6

9.65

9.9

9.4

656–665

660

48.89

.0331

188.7

9.74

10.0

9.5

666-675

670

49.76

.0332

189.8

9.83

10.1

9.6

676-685

680

50.64

.0332

191.0

9.92

10.2

9.7

686-695

690

51.51

.0333

192.1

10.01

10.3

9.8

696-705

700

52.38

.0333

193.2

10.09

10.4

9.8

706-715

710

53.26

.0334

194.4

10.17

10.4

9.9

716-725

720

54.13

.0335

195.5

10.26

10.5

10.0

726-735

730

55.01

.0335

196.6

10.34

10.6

10.1

736-745

740

55.88

.0336

197.8

10.42

10.7

10.2

746-755

750

56.75

.0336

198.9

10.50

10.8

10.2

756-765

760

57.63

.0337

200.1

10.58

10.9

10.3

766-775

770

58.50

.0338

201.2

10.66

10.9

10.3

776-785

780

59.38

.0338

203.3

10.74

11.0

10.4

786-795

790

60.25

.0339

204.5

10.82

11.1

10.5

796-805

800

61.12

.0339

205.6

10.91

11.2

10.6

806-815

810

62.00

.0340

206.7

10.99

11.3

10.7

816-825

820

62.87

.0341

207.9

11.07

11.4

10.8

826-835

830

63.75

.0341

209.0

11.15

11.5

10.8

836-845

840

64.62

.0342

210.1

11.24

11.5

10.9

846-855

850

65.49

.0343

211.3

11.32

11.6

11.0

856-865

860

66.37

.0343

212.4

11.40

11.7

11.1

866-873

870

67.24

.0344

213.5

11.48

11.8

11.2

(c) The dynamometer shall be adjusted to reproduce the specified road load as determined by the most recent calibration. Alternatively, the actual vehicle road load can be measured and duplicated:

(1) Make at least 5 replicate coastdowns in each direction from 70 to 60 km/h on a smooth, level track under balanced wind conditions. The driver must have a mass of 80 ±10 kg and be in the normal driving position. Record the coastdown time.

(2) Average the coastdown times. Adjust the dynamometer load so that the coastdown time is duplicated with the vehicle and driver on the dynamometer.

(3) Alternate procedures may be used if approved in advance by the Administrator.

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Cite this article: FindLaw.com - Code of Federal Regulations Title 40. Protection of Environment § 40.86.529–98 Road load force and inertia weight determination - last updated January 02, 2025 | https://codes.findlaw.com/cfr/title-40-protection-of-environment/cfr-sect-40-86-529-98/

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