Phx it’s plain old diesel with no additives, per the tanker drivers.
Costco on the other hand advertises they have “up to” 5% Bio.
I always question when anyone claims “up to”.
There’s only 2 Costco’s in Ariz with diesel.
2007.5 GMC Sierra 3500 SRW L.B."BLACK" C.C. 4X4 LMM Z71
DIY stock airbox mod, aFe ProGuard 7, OEM drop-in
EFILive ECM ATP - Heavy Tow Tune with Turbo Brake.
EFILive TCM Duramax Tuner
DHD Cold Side High Flow Intake Pipe, DHD PCV Re-Route, AirDog 4G100
Castrol Hypuron/Vecton 15W40 synthetic blend oil
Donaldson P550832 2 qt oil filter
2007 Yukon Denail "BLACK" 6.2 gasser
DIY stock AirBox Mod, K&N, Airaid intake, EFILive TCM only tuning