Well,
For the time being, I have installed this multimeter in my ALTO, non- EFI engine and it is working OK
For the RPM measurement , EFI and Non-Efi use different techniques. For RPM measurement in non-efi, RPM signal is directly taken from -ve side of ignition coil. Then after some filtering and condition circuits, RPM measurement are made.
With EfI cars, I am sure, RPM signal is available on some connector pin from the ECU. This signal is already conditioned in ECU. So it can be directly interfaced.
What is required is that RPM signal connector pin need to traced either from ECU specifications or from in dash tach.
The same method is used in CNG switch for efi cars (correct me if I'm wrong), RPM signal is interfaced to switch from pet to CNG for RPM switch point.
Specific Car ECU model can be googgled to find RPM signal point and format.
I'm working to figure out this multimeter for efi engine for RPM measurement. The rest of measurements are common.
I 'll be happy if I could work with you for this RPM measurement.