Hello Everyone I presently use Castrol GTX 5w30 cold months, 10w30 warmer months in my 1995 Nissan 4x4 V6 truck. I change the oil every 3 months or 3000 miles (WCF)without fail. Well, I have read there are some other great Dino oils as well . some other names are Pennzoil, Chevron, and Motorcraft. Naming the four above mentioned oils what is my best bet? Thanks in advance.