# 40 CFR 86.529-98 - Road load force and inertia weight determination.

(a)

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

F = A + CV 2

(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

Loaded vehicle mass (kg) Equivalent inertial mass (kg) Force coefficients Force at 65 km/h (nt) 70 to 60 km/h coastdown calibration times
A (nt) C (nt/(km/h) 2) Target time (sec) Allowable tolerance
Longest time (sec) Shortest time (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.

[ 63 FR 11849, Mar. 11, 1998, as amended at 80 FR 9104, Feb. 19, 2015]
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