I switched to Delvac on Saturday. When I start the truck cold the pressure is 70 (used to be 90-100). When it gets to operating temp and Im sitting at a light (61 degree day) it drops to 20psi maybe lower. This seems very low and Im really worried. Whats everyone else here think? I get 2 3/4ths bars on the gauge. The guage is 30 psi per 4 marks. So my calculator tells me thats 20.6 psi at hot idle.