ECE R49

The R49 is a 13-mode steady-state diesel engine test cycle introduced by ECE Regulation No. 49 and then adopted by Directive 88/77/EEC [2871]. It had been used for type approval emission testing of heavy-duty highway engines through the Euro II emission standard.

Since the Euro III stage (October 2000), the R49 cycle has been replaced by the ESC schedule. The R49 test remains a regulatory testing procedure in countries that still accept Euro II or earlier emission standards.

The R49 test is performed on an engine dynamometer operated through a sequence of 13 speed and load conditions. Exhaust emissions measured at each mode are expressed in g/kWh. The final test result is a weighted average of the 13 modes. The test conditions and weighting factors of the R49 cycle are shown in Table 1 and in Figure 1. The table also shows the weighting factors of the former US 13-mode test. The areas of circles in the graph are proportional to the weighting factors for the respective modes.

The running conditions of the R49 test cycle are identical to those of the US 13-mode cycle. The weighting factors, however, are different. Due to high weighting factors for modes 6 and 8 (high engine load), the European cycle is characterized by high average exhaust gas temperatures.