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1989 BMW 325i Smog Check Dynomometer Testing RPM Speed

Past smog testing recorded for my 1989 BMW 325i at 15/25 mph had the RPMs of 1700/1800 range. This time they’re in 2300/2600 range. Why? Is the objective to achieve “speed” or an RPM level? If RPM level is required, where in state documents are these levels specified? I can’t seem to find anything about required RPM levels needing to be achieved during dyno testing.

Answer:

The required RPMs are set by the State of California, and the information is downloaded to the smog check machine. The smog check process requires a technician to drive a vehicle in 2nd gear (for standard transmissions) and obtain the correct RPMs in order to complete the smog check. The "correct" RPMs will be displayed in a window on the smog machine while the smog test is being administered. The technician will need to keep the RPM marker within this window during the dynamometer portion of the smog test. posted by SmogTips Support

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