The annual circulation tax (Impuesto sobre vehículos de tracción mecánica) is imposed in Spain on an annual basis based on a Fiscal horsepower. Does anybody know the formula for calculating fiscal horsepower from physical properties of the vehicle?
I am looking for the formula, or algorithm, as opposed to a specific case.
From the ACEA 2016 Tax Guide, page 250:
a). for four-stroke internal combustion or spark ignition engines:
hp = 0.080 * (0.785 * D^2 * R)^0.6 * N
b). for two-stroke internal combustion or spark ignition engines:
hp = 0.11 * (0.785 * D^2 * R)^0.6 * N
Where:
D = the diameter of the cylinder in cm
<p>R = the stroke of the piston in cm</p> <p>N = the number of cylinders of the engine </p>c). for rotary engines
hp = Re/7
Where:
Re= effective rating
