It has one element heating the oil passage and another heating the air passage.  I may be mistaken, but I think it runs a fair bit warmer then 145.  When I was learning about this I spoke with Tom Kagi, who builds his own gun, and it sure seems that I recall him stating that at approximately 300 degrees there is effectively no difference in viscosity regardless of what oil it is, and that is the key to making a nozzle work consistantly on unknown oil.

When I mounted a 20 gallon tank inside the mechanical shed with a sump and drain, with the outside supply coming into it, and the pump running the gun off of it, that's when I would really say that our setup became adequate.  It still requires some work, but now it can be counted on to run for days at a time without being fiddled with.  Before, any time the temperature changed, you were fiddling with it, and if it was hard cold, you could count on trouble.    Now, I have to constantly remind myself that if it is acting up, I probably better go check the tank, 'cause it's probably about empty.  I don't know why but it just refuses to make heat without oil!