Too much load?
It's been really hot here lately and outside temps. have been in the mid-90s. Whenever I'm sitting at a stoplight or just idling with the A/C on, the car starts to drop in rpms (lower than normal idle speed) and oil pressure drops to around 25-30 psi. Is the car simply just experiencing too much load with the high temps., radiator fan going on and A/C blowing?
She has a lot of miles, but I would like to remedy the situation so I don't have to turn off the A/C everytime I come to a stop.

