Oil Brand Quality?

[Big Red]

Hi Everyone
I own a 1995 Nissan Hardbody V6 4x4 with 71,000 miles on it, and a 1998 QX4 4X4 V6 with 50,000 miles on it. I change the oil and filter in both every 3 months or 3000 miles (WCF- Usually months before miles)using Castrol GTX 5w30 winter time- 10w30 warm weather and Nissan oil filters. I have been thinking about other brands of dino oil ie:Chevron, Motorcraft, Pennzoil,or Shell something I can buy at a Wallmart or autoparts store.Are any of the other oils a better choice than Castrol GTX for overall protection/ performance/quality?
Thanks in advance

 

[Al]

Look at the used oil analysis and read comments. Personally I think that Chevron is at least the equal of the Castrol. It wouuld probably be my choice in dino oils. Especially in the 10W variety. The 5W Castrol has thinned out in the past. GTX 10W-30 is very good. Some folks here swear by the Motorcraft.