There was no noticeable difference between the two. That's why I switched to Mobil 1. People told me unless I was racing my truck, I wasn't going to see any added benefits with Royal Purple. I've used Mobil 1 in the last 3 oil changes and it's great stuff. I buy the 5 qt. jug at Wal-Mart for $28 (I think) and then just another single quart.
Hey i saw a couple of posts where your talking about oil. Just wondering if you noticed any differences between Royal Purple and Mobile1. Its coming up soonish for an oil change and im thinking switching over to synthetic. Thanks