That’s 0-5 volts. Most modern sensors (not all) provide a 0-5 volt signal to the ECU/PCM. Like I said before, buy the OT1 the rpm reading will be accurate enough (I believe it samples 12 times a second). As for jacking up your car and doing a 4th gear pull you should really think about spending the money on some dyno time and we’ll give you a rpm/af printout and copy it to your jump drive if you like. For $149+shipping of the OT1 you could do a few different dyno sessions and actually get alot more info…