That is not a bad estimate you outlined. You are assuming the car has zero value at 150k miles. That isn’t true. Its value depends on many many things. Lets assume its worth $3000 at 150K dropping your estimate to 21 cents/mile.
It varies greatly on the car you choose, where you live, how you drive and how well you maintain your car. That might not be a bad estimate for a Corolla or Civic but way off for a Mini based on the histories of each. They real key is the $10K breakdown.
2 sets of tires $1000, 2 sets of brakes $1500, 20 oil changes $1200, Wiper blades $120, 2 Timing belts (for cars that need them ) $1400, water pump $200, fuel pump $400. 3 Coolant changes $300, 2 Trans fluid changes $250. That’s $6370 right there. Many would increase the frequency oil, coolant and trans fluid changes but it is close. That shows me 19 cents/mile for a generally high quality, high reliability car.
So business deduction is now $0.56/mile which includes gas and insurance costs, charity is $0.14/mile which doesn’t even cover wear and tear, let alone gas and insurance. Go figure.
Here is what the IRS has to say;
"The business, medical, and moving expense rates decrease one-half cent from the 2013 rates. The charitable rate is based on statute."
It is written into the tax code at 14 cents/mile and hasn’t changed for a long time.
There is an alternative way of deducting the mileage;
“The 14 cents per mile charitable rate is optional. Instead, a volunteer can deduct actual variable costs of operating the car for volunteer purposes. These include gasoline and oil and all taxes thereon. They do not include general repair and maintenance expenses, depreciation, registration fees, or the costs of tires or insurance”
Not sure which would give a higher deduction but I know which is harder to keep track of…