Tachometer Accuracy

[CraigD]

How accurate should the tachometer be?  I just had mine rebuilt by Palo Alto Speedometer.  Upon reinstallation, I decided to check it's accurcy with an electronic meter.  It's right on at idle - both devices read the same in the range of 800 to 850 rpm.  But at 3000 rpm, the tach reads 250 rpm low.  It doesn't get any worse at 4000 - still 200 to 250 low.  Is that reasonable, or do you think it should be more accurate?


Craig
'70 280SL Euro, Manual,  Leather
Silver/Black

 

[mdsalemi]

Craig,

I'll hazard a guess here.  Assuming that all is well with your mechanical tach and the cable, that the inaccuracy might more likely be in the electronic version, particularly at higher RPMS.  Due to the way they work I believe they may be suseptable to electronic noise, and not be able to pick up every RPM.  Just a guess.

Michael Salemi
1969 280SL
Signal Red 568G w/Black Leather (Restored)
President, International Stars Section
Mercedes-Benz Club of America