Brent, This a complicated issue, but here goes, in California if you blend 92 octane or over, unless you have very expensive advanced control systems or a Fluidized catalytic cracker
{ A refinery unit} Which alot of California refineries do not have, you have to follow a patent formula owned buy Unocal{union
oil}and therefore have to pay them a royalty on every gallon of gas
without the controls or units above it was seat of your pants blending, unless you followed unocals "recipe" for distillation you could have very costly reblends, so to avoid this the distillation numbers were changed, a 50% of 210° was Unocals recipe, by changing to a 50% at 210.5, which rounds up to 211 you avoid the costly patent, but you make 91 octane, as usual it is all $$$$ and cents!!!
