The EPA UDDS schedule has been developed for chassis dynamometer testing of heavy-duty vehicles (CFR 40, 86, App.I). Sometimes referred to as “cycle D”. It should not be confused with the FTP-72 cycle for light-duty vehicles, which is also termed UDDS.
The following are basic parameters of the cycle:
- Duration: 1060 seconds
- Distance: 5.55 miles = 8.9 km
- Average speed: 18.86 mi/h = 30.4 km/h
- Maximum speed: 58 mi/h = 93.3 km/h
![[chart]](images/udds.gif)
Figure 1. HD UDDS Cycle
The UDDS schedule was a basis for the development of the FTP transient engine dynamometer cycle.