I recently installed a VDO cylinder temp guage and am off on my first trip of 2000mi.  The question is how accurate are these guages and what is an acceptable temperature for the #3 cylinder?

I am seeing 375-425 at highway speeds with 450 degrees at the start whent he alternator is charging the battery.  This sounds high to me, but I am not sure how acuurate the guage really is and am not sure what is an OK range for #3.  Can anyone tell me the range or accuracy of the guage.

David

PS.  I just finished a 26 hour, 1200 mile trip and everything seems to run fine, it's been 90+ degrees out.  BTW the flaps are all the way open and the tin is prettly well sealed.