The Chevron Texaco merger to form ChevronTexaco, when it first occurred, disallowed ChevronTexaco from owning the Texaco stations in North America. They, instead, continued to be owned by Shell. They did not have Chevron gasoline or diesel.
As of July 1, 2004, both ChevronTexaco and Shell have the rights to the Texaco name and ChevronTexaco has chosen to use the name in 13 mostly-southern states and the District of Columbia. The thirteen states are Texas, Louisiana, Mississippi, Alabama, Georgia, Florida, Tennessee, Kentucky, West Virginia, North Carolina, South Carolina, Virginia and Maryland. Chevron is also currently rolling out Chevron-owned Texaco stations in seven states in the West. They are Oregon, California, Idaho, Nevada, Arizona, and New Mexico.
This makes it confusing since some of the Texaco stations in these states will be owned by Shell and some of them will be owned by ChevronTexaco. As of now the only way to tell which Texaco stations in those states are owned by ChevronTexaco is that they will accept the Chevron credit card and will advertise that fact on the premises. If you do not live in one of the states mentioned, all of your state's Texaco stations will be Shell-owned. If you do live in one of the states mentioned, those Texaco stations found there may be owned by either Shell or ChevronTexaco.
All of this will become easier in less than two years time (07/01/06). At that time ChevronTexaco will own exclusive rights to the Texaco name and any Chevron or Texaco stations you find anywhere in the US will be selling ChevronTexaco fuel (and not Shell fuel).