Three months or 3000 miles, whichever comes first.
Pads and tampon packages come in sizes large enough that they should last about as long... so you're going to be shopping for them about the same time.
Mid 90s they had a faulty coating on the inside of the intake manifold that would flake off and damage the cylinder walls. How's your tranny and power steering pump holding up?
Power steering's fine, it doesn't look like the original pump, but the tranny's getting kinda weak. I'm planning on putting a new torque converter in once I go home for the summer. It's an early 80s truck, so it still has the old cast (I think they're cast anyway) manifold
Actually, you should look at the owner's manual to see how many miles before an oil change, many cars recommend 5000 mile or longer oil changes. The 3000 mile number is a holdover from years past with poorer engines.
Pads and tampon packages come in sizes large enough that they should last about as long... so you're going to be shopping for them about the same time.