[MrB]

The weight requirement for the tax deduction should have been another requirement.

It was meant to give a deduction for true equipment and capital investment (like tractors),
but has been applied to other vehicles under this lazy standard of looking only at the weight.

[thackney]

The 6,000 lb curb weight is the government distinction between “Heavy Duty” vehicles intended for more than passenger transport. Farm and other business often needs that capacity found in F-250 and larger type trucks. Weight limit is used for EPA requirements like the CAFE standards.

http://www.epa.gov/otaq/imports/glossary.htm#hdvhdt

- - - - -

The Tax deduction now includes language to put larger SUV and crossovers into a more limited deduction.

http://www.section179.org/section_179_vehicle_deductions.html