When running on the interstate at about 60mph, my oil pressure reads about 20 to 30 (about 25% of the gauge) but it drops to almost zero at the red light.

This is not normal is it?

Thanks for any help

I would check the sending unit on the passenger side to see if there is a leak or if its bad. Then do a check on the gauge to make sure its reading right. Check your oil level. I know my 76 oil pressure runs about 60 when running to 55-70. When the oil gets low the gauge sits lower like yours.

Just a little more info -

I did have the oil pressure checked at a shop not long ago and it was fine. I just never paid attention to the gauge really til yesterday.

When the car starts, the Oil Pressure is about 45 to 50. But the gauge reads about 25 after I pull out of the driveway and goes to zero at a red light.

I saw on some other boards where other folks have the similar experience. The general idea is that these Oil gauges aren't very good.....but I will check my oil pressure just to be sure......

Buy a new sending unit. THey are relatively cheap and may help you out. MIne was nearing Zero with my original 37 year old gage. WHen I replaced it, I was reading about 20 psi at idle. THE sending units go bad after a while, its a common problem.