Federal regulations · Through 2026-08-25 · Newer source version available

40 CFR Appendix V to Part 86: Appendix V to Part 86—The Standard Road Cycle (SRC)

1. The standard road cycle (SRC) is a mileage accumulation cycle that may be used for any vehicle which is covered by the applicability provisions of § 86.1801. The vehicle may be run on a track or on a mileage accumulation dynamometer.
2. The cycle consists of 7 laps of a 3.7 mile course. The length of the lap may be changed to accommodate the length of the service-accumulation track.
Description of the SRC
Lap Description Typical accel rate (MPH/s)
1 (start engine) Idle 10 sec 0
1 Mod accel to 30 MPH 4
1 Cruise at 30 MPH for 1⁄4 lap 0
1 Mod. decel to 20 MPH −5
1 Mod accel to 30 MPH 4
1 Cruise at 30 MPH for 1⁄4 lap 0
1 Mod. decel to stop −5
1 Idle 5 sec 0
1 Mod accel to 35 MPH 4
1 Cruise at 35 MPH for 1⁄4 lap 0
1 Mod. decel to 25 MPH −5
1 Mod accel to 35 MPH 4
1 Cruise at 35 MPH for 1⁄4 lap 0
1 Mod. decel to stop −5
2 Idle 10 sec 0
2 Mod accel to 40 MPH 3
2 Cruise at 40 MPH for 1⁄4 lap 0
2 Mod. decel to 30 MPH −5
2 Mod accel to 40 MPH 3
2 Cruise at 40 MPH for 1⁄4 lap 0
2 Mod. decel to stop −5
2 Idle 5 sec 0
2 Mod accel to 45 MPH 3
2 Cruise at 45 MPH for 1⁄4 lap 0
2 Mod. decel to 35 MPH −5
2 Mod accel to 45 MPH 3
2 Cruise at 45 MPH for 1⁄4> lap 0
2 Mod. decel to stop −5
3 Idle 10 sec 0
3 Hard accel to 55 MPH 4
3 Cruise at 55 MPH for 1⁄4 lap 0
3 Mod. decel to 45 MPH −5
3 Mod accel to 55 MPH 2
3 Cruise at 55 MPH for 1⁄4 lap 0
3 Mod. decel to 45 MPH −5
3 Mod accel to 60 MPH 2
3 Cruise at 60 MPH for 1⁄4 lap 0
3 Mod. decel to 50 MPH −5
3 Mod. accel to 60 MPH 2
3 Cruise at 60 MPH for 1⁄4 lap 0
3 Mod. decel to stop −4
4 Idle 10 sec 0
4 Hard accel to 80 MPH 3
4 Coastdown to 70 MPH −1
4 Cruise at 70 MPH for 1⁄2 Lap 0
4 Mod. decel to 50 MPH −3
4 Mod accel to 65 MPH 2
4 Cruise at 65 MPH for 1⁄2 lap 0
4 Mod. decel to 50 MPH −3
5 Mod accel to 75 MPH 1
5 Cruise at 75 MPH for 1⁄2 lap 0
5 Mod. decel to 50 MPH −3
5 Lt. accel to 70 MPH 1
5 Cruise at 70 MPH for 1⁄2 lap 0
5 Mod. decel 50 MPH −3
6 Mod accel to 70 MPH 2
6 Coastdown to 60 MPH −1
6 Cruise at 60 MPH for 1⁄2 lap 0
6 Mod. decel to 50 MPH −4
6 Mod. accel to 65 MPH 1
6 Cruise at 65 MPH for 1⁄2 lap 0
6 Mod. decel to stop −4
7 Idle 45 sec 0
7 Hard accel to 55 MPH 4
7 Cruise at 55 MPH for 1⁄4 lap 0
7 Mod. decel to 40 MPH −5
7 Mod. accel to 55 MPH 2
7 Cruise at 55 MPH for 1⁄4 lap 0
7 Mod. decel to 40 MPH −5
7 Mod. accel to 50 MPH 2
7 Cruise at 50 MPH for 1⁄4 lap 0
7 Mod. decel to 40 MPH −5
7 Mod. accel to 50 MPH 2
7 Cruise at 50 MPH for 1⁄4 lap 0
7 Mod. decel to stop −5
The standard road cycle is represented graphically in the following figure:

Where this section sits in the code

Title 40—Protection of Environment
CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY
SUBCHAPTER C—AIR PROGRAMS
PART 86—CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES

2. The cycle consists of 7 laps of a 3.7 mile course. The length of the lap may be changed to accommodate the length of the service-accumulation track.

Description of the SRC

Lap Description Typical accel rate (MPH/s)

1 (start engine) Idle 10 sec 0

1 Mod accel to 30 MPH 4

1 Cruise at 30 MPH for 1⁄4 lap 0

1 Mod. decel to 20 MPH −5

1 Mod accel to 30 MPH 4

1 Cruise at 30 MPH for 1⁄4 lap 0

1 Mod. decel to stop −5

1 Idle 5 sec 0

1 Mod accel to 35 MPH 4

1 Cruise at 35 MPH for 1⁄4 lap 0

1 Mod. decel to 25 MPH −5

1 Mod accel to 35 MPH 4

1 Cruise at 35 MPH for 1⁄4 lap 0

1 Mod. decel to stop −5

2 Idle 10 sec 0

2 Mod accel to 40 MPH 3

2 Cruise at 40 MPH for 1⁄4 lap 0

2 Mod. decel to 30 MPH −5

2 Mod accel to 40 MPH 3

2 Cruise at 40 MPH for 1⁄4 lap 0

2 Mod. decel to stop −5

2 Idle 5 sec 0

2 Mod accel to 45 MPH 3

2 Cruise at 45 MPH for 1⁄4 lap 0

2 Mod. decel to 35 MPH −5

2 Mod accel to 45 MPH 3

2 Cruise at 45 MPH for 1⁄4> lap 0

2 Mod. decel to stop −5

3 Idle 10 sec 0

3 Hard accel to 55 MPH 4

3 Cruise at 55 MPH for 1⁄4 lap 0

3 Mod. decel to 45 MPH −5

3 Mod accel to 55 MPH 2

3 Cruise at 55 MPH for 1⁄4 lap 0

3 Mod. decel to 45 MPH −5

3 Mod accel to 60 MPH 2

3 Cruise at 60 MPH for 1⁄4 lap 0

3 Mod. decel to 50 MPH −5

3 Mod. accel to 60 MPH 2

3 Cruise at 60 MPH for 1⁄4 lap 0

3 Mod. decel to stop −4

4 Idle 10 sec 0

4 Hard accel to 80 MPH 3

4 Coastdown to 70 MPH −1

4 Cruise at 70 MPH for 1⁄2 Lap 0

4 Mod. decel to 50 MPH −3

4 Mod accel to 65 MPH 2

4 Cruise at 65 MPH for 1⁄2 lap 0

4 Mod. decel to 50 MPH −3

5 Mod accel to 75 MPH 1

5 Cruise at 75 MPH for 1⁄2 lap 0

5 Mod. decel to 50 MPH −3

5 Lt. accel to 70 MPH 1

5 Cruise at 70 MPH for 1⁄2 lap 0

5 Mod. decel 50 MPH −3

6 Mod accel to 70 MPH 2

6 Coastdown to 60 MPH −1

6 Cruise at 60 MPH for 1⁄2 lap 0

6 Mod. decel to 50 MPH −4

6 Mod. accel to 65 MPH 1

6 Cruise at 65 MPH for 1⁄2 lap 0

6 Mod. decel to stop −4

7 Idle 45 sec 0

7 Hard accel to 55 MPH 4

7 Cruise at 55 MPH for 1⁄4 lap 0

7 Mod. decel to 40 MPH −5

7 Mod. accel to 55 MPH 2

7 Cruise at 55 MPH for 1⁄4 lap 0

7 Mod. decel to 40 MPH −5

7 Mod. accel to 50 MPH 2

7 Cruise at 50 MPH for 1⁄4 lap 0

7 Mod. decel to 40 MPH −5

7 Mod. accel to 50 MPH 2

7 Cruise at 50 MPH for 1⁄4 lap 0

7 Mod. decel to stop −5

The standard road cycle is represented graphically in the following figure:

Collected 2026-08-27T02:26:04Z. Source file · JSON

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