Originally Posted by davidyan

Several years ago, auto manufacturers got together and put together a list of "top tier gasoline brands" which are recommended Here is the link:

Top Tier Gasoline

Whats not clear is if the manufacturers really believe they are technically better or if its just some promotional agreement they have with the oil/gas companies.

With regards to octane however, what I've always been taught by some auto engineers and ASE Master techs (i took a bunch of classes at a tech school out of pure interest years back) is that octane requirements do matter however, IF your car requires it based on engine compression. Our 370Z's do, so you should use a 91 or higher octane. The terms "premium" or "regular" don't really mean that premium is higher quality. The higher octane burns slower which prevents pinging in higher compression engines. Likewise, lower octane burns faster.