Name:   GoneFishin - Subject:   WATCH THE GAS YOU BUY Date:   8/16/2022 10:31:56 PM

Ofter you will jump on gas priced a little lower. However, if you check your car manual you will probably see under recommended fuel the term TOPTIER. Gas that is delivered to the station can be from any refiner. What customizes it are additives which are added by the station and are then considered to be TOPTIER.  Name brands such as Shell, Chevron, Citgo, Exxon, Texaco, and Mobie are all considered TOPTIER. According the list,  gas sold by COSTCO  is  and Sam's CLUB is not TOTIER.

Check your manual.