ROYAL PURPLE!!! 5W-20. I get mine from American Muscle, shipped to my door for $45.75 and thats & quarts. Then I get me either a Ford Racing Filter for $10 or K&N oil filter for $12.
At 5k miles the oil still looks pretty good for all the in town driving I do with that car especially with the motor I have. One thing I did notice going from Castrol 5W-20 (i used during the break-in period for the new motor) to the 5W-20 Royal Purple is the engine when started up cold ran smoother until the engine came up to full temp and the damn thing runs smoother in my opinion. I know its because of synthetic versus reg. oil but for the price I get it I dont think I can beat it.
I looked the other day at O'Reilly's and Advance and they are getting now $7.50 a quart for Royal Purple or any Synthetic Oil!! bunch of crap!!!