Originally Posted by Spartan 1771

I don't know what your dealership uses, but the two I have dealt with both used Mobile 1. Although a great oil, the manufacturer recommends ester oil. Redline is ester, and like I said, I noticed an immediate difference. I can't get Redline by me, but I order it from Amazon. It's worth the trouble of ordering it. You may also want to consider changing your transmission and rear dif fluid. The factory fluid isn't great. A quality fluid in both can make a noticeable difference. I also use redline in both. Is your Z a manual or automatic?