Switching to the new WLTP consumption cycle does not only affect fuel consumption, but in a few cases it also affects the power output. The most prominent example is the BMW X3 M40i, because here the rated output of previously 265 kW / 360 hp drops to “only” 260 kW / 354 hp. The culprit is the integration of the gasoline particulate filter, which is absolutely necessary to comply with the new limit values of certain exhaust gas components and increases the exhaust backpressure.
The Otto particle filter also has an effect on the torque of the B58 six-cylinder unit. Although the maximum torque of the BMW X3 M40i remains unchanged at 500 Newton meters, it is in a slightly narrower band of the engine speed range. The torque maximum is still reached at 1,520 rpm, but the plateau peaks now at 4,500 compared to the previous 4,800 rpm.
It is noteworthy that the weight of the BMW X3 M40i does not increase despite more complex exhaust gas purification: the DIN curb weight still amounts to 1,810 kilograms. However, due to the lower engine power, the power-to-weight ratio deteriorates from 5.03 to 5.11 kilograms per horsepower.
The standard consumption according to WLTP is 9.1 liters per 100 kilometers and is therefore is almost one liter higher than the old NEDC rules, when the X3 M40i was rated at 8.2 to 8.4 liters per 100 kilometers. As a result, the official CO2 emissions increase from 188 to 193 to 206 to 207 grams per kilometer, which makes the German motor vehicle tax slightly more expensive. So far, the engine has “only” met the Euro 6 emission standard, but it now meets the requirements of the Euro 6d TEMP emission standard.
The performance of the BMW X3 M40i even with 354 hp stays the same: The factory specification for the sprint from 0 to 100 km/h is unchanged at 4.8 seconds, the maximum speed is still limited electronically to 250 km/h.
Only these changes are relevant to the European models, the US market is governed by a different set of emission rules so the power output stays the same.[Source: Bimmertoday]