No, I never switched back. And like I said, I never thought that syn caused the oil burning, but it was always a suspect for me. I bought my original VX with 25,000 miles on it, and switched to syn with my first oil change. And it burned oil right away. So it was just a thought. I have no concrete evidence that syn caused or increased the oil burning. The only switch I ever made with my VX was from Mobile-1 to Shell Rotella HW synthetic. And with the Rotella, I can say it might have burned a little less oil, but it was a negligible amount. Some VXes just have an oil appetite I guess!

Bart