Doing your math, I get:
60 hr/wk * 50 wk/yr * 60 mi/hr * $3.5/gal * 0.1 gal/mi = $63,000 /yr
$63,000 /yr * 0.2 * 3 = $37,800 /yr in savings
Doing your math, I get:
60 hr/wk * 50 wk/yr * 60 mi/hr * $3.5/gal * 0.1 gal/mi = $63,000 /yr
$63,000 /yr * 0.2 * 3 = $37,800 /yr in savings