I work with a 12 mile one way commute.
I will start working from home 3 days per week, saving $15 per week in gas alone. Annual gas savings $750
$15 of gas at $3.163/gallon = 4.74 gallons
24 miles * 3 = 72 miles
72 miles / 4.74 gallons = 15.2 mpg
Your primary commuter vehicle averages 15.2 mpg? Or is gas much more expensive where you live than the national average?
Yep just hideous isn't it! 1999 Mercury Mountaineer. (275K) Probably averages 17 overall. I gave my 2001 Toyota Camry to my daughter. It had 375K and still runs great with 30 mpg.
Bought the Mountaineer for 2K 2 years ago. If I replaced it with a 10K 30 mpg vehicle it would cost me around $700 per year in investment opportunity costs. Although, prior to moving to the less commute idea I had considered buying a new ford focus for 13K that would average 34 mpg and save me about $1,200 per year in gas but cost me an additional $500 in insurance. Plus I would still keep the Mountaineer for camping and hauling kayaks.
By the way, in Missouri we usually have the lowest gas prices in the nation and I can buy gas today for 2.70.
Bottom line -- I may decide to buy a new Ford Focus for around 13K. Please don't anyone slam me with the idea that I need to buy a 6K used car. I'm not in debt and in very good shape financially. I'm 55, so the Focus would probably last me the rest of my life with my long term anticipated average annual mileage of 7,000 per year.
Thanks for you astute math work!