I used to be a Valvoline girl. It was the only oil I would use. I started working at the job I have now and got a discount on Pennzoil. I used Penzzoil Synthetic blend in my !999 Dakota with 153,000 miles for 3 oil changes. It was amazing how much cleaner the oil was by the 3rd drain! So now, that's all I'll use is Pennzoil.