If Exxon has to pay more in taxes in those countries, you can be sure that they are charging the retailers more, and the retailers are passing that on to the consumer.
Rule #27 of Capitalism - only the end user pays taxes.
Or we could just invest in bringing alternative energy sources to market, like we have been talking about doing for the last 40 years. Oh wait, that would make us socialists, or worse, communists!
Nevermind.