Autometer Temp vs Speed Pro Temp, what's right?

[Bobo]

Autometer gauge reads about 10-15 degrees cooler than the SP reading. They are both reading from the front of the intake. Which guage is lying lol.

 

[mosk]

You have some company: I have the same general thing going on, except in my case, the AutoMeter gauge reads 10 - 15 degrees higher than the SpeedPro.

As you said, at least one of 'em is lying

 

[BLKMGK]

Autometer electric?

One of the guys on HybridZ compared an electric gauge vs a labratory thermometer and found the readings to be noticabley "off" - he's had to recalibrate it. Not sure the manual meters are much better.

Honestly though, what's it matter? Drive the car and get used to where the temp usually runs. When\if it runs noticably hotter you'll know there's a problem. With the FAST it's been tuned with the temp sender in there right? So far as it knows whatever temp it was tuned for was "normal" whether it was 100 degrees or 500. Don't sweat the small stuff

 

[Lance]

The FAST ECU uses the standard GM calibration data for its transfer function. There probably is some room for improvement but as BLKMGK so astutely pointed out, why bother? There is marginal differences between individual sensors and small errors that can be introduced from many other factors such as wire length and component tolerances. I too have noted errors when comparing the temperatures from a typical gauge to the ECU reading. I have also consistantly determined the ECU to be more the more accurate of the two in a given set of test conditions. The effort of trying to accurize the readings to the nth degree doesn't really lend itself to any significant gains in performance.