If i take the car out and time my 0-60 times is the speedometer accurate enough to do this. Does the gauge take more time to reach 60 then the car does? My old 79 would be reading a slower speed on hard acceleration but as soon as i let off the gas it would still be going and catch up.

 

If your just curious then yes but if you are serious then take it to a dyno.

 

If you buy certain gauges, it will figure that out for you. I replaced my gauges with Nordskog digital gauges, and the speedometer not only has pushbutton calibration, but it has the capability of measuring and displaying your 1/4 mile time & 0-60 time. The only catch is you gotta make sure you get the calibration on the speedo right, or neither of those figures will be accurate...

 

G-Tech makes a device that accuratly reads your 0-60 time as well as other things. Otherwise, unless you have strayed your car in wheel/tire size from stock or done anything to change the gearing, your stock speedo should be pretty darn accurate.

 

No i don't think your stock gauges are accurate enough to try to calculate this. When i had my scanmaster in and on the mph setting the speedo would fall behind by up to 5mph on a hard acceleration compared to the scanmaster.