A few years ago Grist’s Ask Umbra did a comparison of gas companies. Since then, I’d been loyally going to Conoco-Phillips-66, who at that time was the best in show for humanitarian and environmental reasons. My information is sadly now outdated, so I did some searching to find out who tops the lists now. The answer seems to hover around 3 different companies, depending on your sources. The Fox News (??) article linked here rates Sunoco and BP as hovering at the best.
I also checked A Better World Handbook (which didn’t have dates attached to it, but seems to have been put together at least after 2004), and they agreed, with Marathon taking third—if there were a medal stand of gasoline company olympics. Sierra Club (whom the Fox News article also quotes) puts the same companies at the top, so after a while, I started seeing that either there are definite patterns or everyone Googles the same search terms as I did.
Bottom line: Sunoco/BP (and Amoco) “good”, ExxonMobile bad. Since gasoline is never good, it’s in quotes there. Maybe I should say “four wheels bad, two feet better.”