Chevron seems to be the only gas station chain that has not yet implemented EMV on a wide-scale basis in-store.

Chevron only requires CVV on in-store purchases in some California locations on Visa and MasterCard.

Outside of California, they are requiring zip code on in-store purchases at some locations on all card types for Credit (not CVV).

They are doing the CVV in California because state law prohibits them from wanting the zip code on an in-store transaction. Skimming is a very significant fraud loss reason in California anyway, specifically about three counties down in southern California which account for probably 90% of the fraud in the entire network, so taking the CVV should eliminate some fraud.