I was wondering if anyone could tell me how accurate our factory tachs are? A friend of mine put an aftermarket tach in his '88 stang, and his stock tach was off by a full 1000rpm up top. I was wondering if anyone knew how far off ours are. I have a new motor and don't have the $ for a new tach just yet. But I have taken it to the track, and I don't like NOT knowing for sure where I am shifting. Thanks for any help.

 

Well, to be honest, our factory tachs are not too good. Neither are the rest of the gauges, really. Most of our instruments are now at least 12 years old and that doesn't help. My tach reads around 2500 RPM at idle when my Autometer reads 650 RPM, just for comparison.

The problem with our tachs is a capacitor. If you take the gauge cluster out you can take off the old one and solder in a new one from somewhere like Radioshack. I don't know what kind of capacitor, though, but if you search I think you can find the valve or size you need. You could also try and find a used gauge cluster at a junkyard and compare your old one with that one.

If I were you, I would buy an aftermarket tach from Autozone or Advance, and use it until you can afford a better one. When you get the better tach, just return the cheap one. You can probably get one for about $40, instead of about $120.