[thackney]

The price of crude is supposed to be about 80% of the price of a gasoline.

When has it ever been at 80%?

GASOLINE PUMP COMPONENTS HISTORY
http://www.eia.gov/petroleum/gasdiesel/gaspump_hist.cfm

[Chad_the_Impaler]

Presumably when crude oil goes down the corresponding taxes go down by a similar amount. 63%+13%=76%.

[ROCKLOBSTER]

OK, let me rephrase that. First, it should have been .75.

In order to get a quicky price guesstimate, you divide the price per barrel by 42(gallons)

$65/42 = $1.55 (per gallon of crude)

Then you divide the price per gallon by the factor .75

1.55 /.75 = 2.07

Then you add the tax (.45)

$2.07 + .45 = $2.52