So I saw Autocrack had 5 quarts M1 EP and a M1 filter for $34.99 sale going on, I bought it immediatly and really didn't check when I was buying because 1) I was tired 2) china-food was waiting back home 3) I didn't plan on buying when I went in and it was an impulse buy anyway... I get home, and it's the old GF-4 bottles.... well played Autocrack.. Any reason I shouldn't keep the stuff and see if another autozone has GF5/dexos 1 stuf? Keeping in mind that I do have a vehicle that requires Dexos 1. I'm thinking it has to of been sitting on the shelf for 1-2 years already if it's still the GF-4 formulation, so my other question is what's the typical shelf-life? Thanks in advance.