I have a 60 mile trip to work.
46 weeks a yearx 60 miles dayx 5 days = 13,800 miles
46 weeks a yearx 60 miles dayx4 days = 11,040 miles
Savings of 20%
At 30 MPG I'll use 460 gallons of gas doing the 5 days per week.
At 30 MPG at 4 days per week I'll use 368 gallons.
About $275 in gas alone I save, not to mention extra wear and tear on vehicle.
BTW I recently went to four 10 hour days and love it. I currently work Mon-Thu for Fri/Sat/Sun off and the shift is 8 am - 6 pm at night.
I think in many states it's illegal to workj 10 hour days. Anything after 8 hours is an OT deal, mandatory breaks/lunches etc etc. I'm lukcy that my boss says screw the legislation, we'll do it our way