How much oil?

Yea this is probably gonna be a pretty retarded question...I'm changing my oil...how much do I put in a 1996 S-10 Blazer? 4.3 liters?

My computer program shows 4.5 quarts.

honestly, i think its a big mystery what the correct amount is. the owners manual may say 4.5 while repair manuals say 5. in the dealer manual for my truck, it says crankcase capacity is 4.5. is an oil and filter change 5qts or does 4.5qts include the filter?

Your best bet is probably to put in 4 qts in the crankcase, .5 qts in the filter. After you give it sufficient time to completely drain down pull the dipstick and check the level, fill to proper level. After you start the truck and check for leaks let it run for a little while, stop the truck and check your level again.
It seems like every book, manual, dealer or "quick lube" place (best if avoided) has a different amount that they recommend for filling.
Remember to use the proper weight (5W 30) and a good filter (not a fram) when doing your change, and good luck.

I tried out this theory about 2 weeks ago when I changed my oil. 5 qts is a hair too much in my 99' Blazer. I put my blazer on a ramp and let the oil drain for about 1.5 hours to make sure about everything is gone.

So it looks like 4.75 quarts is about what I need.

Your best bet is probably to put in 4 qts in the crankcase, .5 qts in the filter. After you give it sufficient time to completely drain down pull the dipstick and check the level, fill to proper level. After you start the truck and check for leaks let it run for a little while, stop the truck and check your level again.
It seems like every book, manual, dealer or "quick lube" place (best if avoided) has a different amount that they recommend for filling.
Remember to use the proper weight (5W 30) and a good filter (not a fram) when doing your change, and good luck.

If it is a bit older you can use 10w-30