EU: Heavy-duty: R49

Overview
The R49 is a 13-mode steady-state diesel engine test cycle introduced by ECE Regulation No.49 and then adopted by the EEC [EEC Directive 88/77, EEC Journal Officiel L36, 8 Feb. 1988]. It had been used for type approval emission testing of heavy-duty highway engines through the Euro II emission standard.

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

Description
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 below. 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.

ECE R49 Cycle