I've kind of hijacked a couple threads talking about temperature/pressure gauges and their accuracy. Some say that mechanical gauges are more accurate, others seem to believe electric with sensors are just fine. My current gauges are isspro black face and bezel and red pointer. Want to stay with same looking gauges. Sounds like the electric gauges with sensors opperate well below the standard battery voltage with some kind of regulator. So what are your recommendations? Electric or mechanical?

Pressure gauges I say mechanical.

 

Temperature gauges I say electric.

I am opposite, I perfer, electric for fluid pressures "I don't much care for runing live pressurized fluid tubing into my cab", and mechanical for air pressure, temp gauges I go either way, if it is a short straight easy run for the capilary tubing then mechanical if it is a long or gauge is in a hard spot to get to run then electrical.

Electrical  can  be  easier  to   install,   capillary  tubing  can  be  a  bugger!   Plus,  when  it's  time to remove  the sensor wire or  tube  for  component  removal, (manifolds, IP,  etc )   you have to be pretty careful not to  twist up the  'tube.    electrical  all you have to do is  unplug it.       BUT,    I'd  imagine  overall  durability, hence accuracy,  swings  back  to  mechanical.    

I went  with   auto meter  electrical  on  my  last   install,   903  cummins powered  tractor.   Right out of the  box,    the  probe  for the  pyrometer  was  faulty.   ( the  gauge  auto  'zeroes',  goes  through a  self test,   everytime  it's  energized. )  mine  was off  almost 100 degrees.    New probe  was  sent  to me  free,  and  been ok  so  far.     The   coolant  gauge  been  fine so far too.

 

 

Man,   these  days,   any  'high end'   gauge    should  be  pretty darn good   regardless  of    how it's   signaled...   (not  saying  my  auto meter is  high end..  it  was  *affordable*.)

I'm  going to mount  my  FP  on  the  back edge of the hood. (my  2000 ram)  I too  am   a little leary  of   piping  fuel  into the  cab.   (unless  there is  an  isolator version?)

I am not concerned with running the fluids all the way to the gauge in my truck. I have needle valves on all of the lines before they go into the cab as a safety precaution. If you think about it, big rigs and tractors/equipment almost always use mechanical gauges just because of the longevity. How many of the almost 2 dozen gauges in each truck do you think are being used with isolators? Probably none. I am just going off of all of the big rigs my dad has owned/driven over the years. If it was that big of an issue to have gauges fail and pump liquids into the cab, I am fairly certain that truckers would have gone away from straight mechanical gauges a long time ago. 

Just my .02 and IMHO of course.

fuel  would be the only fluid  I'd  keep  isolated..  (from my  gasoline racing days)..    more  for a   'stinking up the cab'  part,  not so much the  'burst into  flames'  worry!  lol,     If  you guys  could  see whats  stuck  on the  floor mats  in  my  trucks, *cow poop*    a little  diesel fuel might actually be a nice  air freshener!   heck,  most days  I could probably   wring out  a  quart of  fuel  from  my   cover-alls.   

 

True,  a  burst   gauge or  tube  would  be  rare,  very rare.    I was  just thinking  *worst case scenario* 

I've always felt (and understood) that mechanical is the most accurate gauge.  That of course doesn’t mean all electrical gauges are inaccurate and that all mechanical gauges are superior either.  I think that accuracy verses inaccuracy is going to come down to the gauge manufacture quality over more than type.  I had a high quality electrical fuel pressure gauge for years and then when it finally failed (as do most electric fuel pressure gauges because of sender failures) I chose to go mechanical rather than replace the electrical.  I found that the mechanical gauge was more accurate than the electrical gauge.

 

As for running fuel into the cab.  That seems to be personal preference but in saying that, I also think its illegal to run fuel into the cab.  Not a big deal unless you care about strictly following the laws or if you happen to be in an accident that results in a fire.  I used an isolator and it works fine.  I think isolators get a bad rap because most of the time they're install incorrectly.