[Hot Tabasco]

Michigan has only one gasoline refinery that is located in Detroit and owned by Marathon. All the gas stations in Michigan, regardless of who owns them, purchase their gasoline from it at whatever price it is being sold for.

So while it appears that Sunoco, BP, Marathon, etc. gas stations are raising their prices in unison, it's because they're all paying the same price for what they're selling you.......

[ExGeeEye]

That’s the closest to a reasonable explanation that anyone has given thus far.

“Almost thou persuadest me...”

[Drago]

RE: post #31 by HT, here is the one Michigan refinery:

https://www.eia.gov/dnav/pet/pet_pnp_cap1_dcu_SMI_a.htm