I used Blackstone Labs, they send you the sample bottles for free, you just mail it in along with a check or payment info. There are plenty of other places that do the same thing. Blackstone doesn't show all of what some of the company's do, I cant remember right off hand what they skipped. It was cheap though and I wanted a base to compare the RP to when the time comes.

Honestly the VR-1 stuff i wouldnt run in a street car. I ran it in my engine after I first put it together, ran that in it regularly and changed it every 2500-3000 miles. When I pulled the engine the first time to make some changes to the heads, cam and intake, I noticed some sludge beginning to form in the oil pan. Most the rest of the engine was fine, just in the bottom of the pan which is where the pickup sits... Really that oil only belongs in a race car that will get the oil changed pretty frequently. BUT it is a fantastic oil for that!! We ran it in our dirt car for a couple years, would change the oil every other weekend, and the engine was perfectly clean and virtually 0 wear was found every season. We also ran mobil 1 a couple years with even better luck then the valvoline!

Amsoil Signature 5w-30!!!