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Javi802
01-28-2016, 02:51 PM
What's up yall.

So my sr, according to data scan, idles at 850rpm..But my tachometer shows 1000.

Well, under load, that difference goes to a 500rpm difference. Crusing at 75mph my tachometer will show 4000rpm, but nissan data scan shows 3500. About a 500rpm difference at any speed besides idle.

Im assuming data scan is showing actual rpm? Taking an actual Reading from the CAS?

SoundEfx
01-28-2016, 03:42 PM
In my limited knowledge, I would assume that data scan would be more accurate. It seems as if it's time to re-calibrate or replace the tach.

Kingtal0n
01-28-2016, 05:51 PM
The gauges in 240sx always seem to read slightly high. MPH does the same thing. I always just thought it was "for safety" they would rather have it too high than too low (officer my speedo said 50!) but thats just a guess. Could just be due to worn/aged electronics. I only imagine the engineers designed it to gradually read higher than lower for safety.