Cost per mile
 

2010 Toyota Rav4
Cost per gallon 2.07
Total gallons in tank 15.9
Est. MPG highway 28
Miles traveled on tank 445.2
Cost per mile 0.004649596

2013 Subaru BRZ
Cost per gallon 2.7
Total gallons in tank 13.2
Est. MPG highway 30
Miles traveled on tank 477
Cost per mile 0.005660377

Slow day at work today, and I wanted to figure out the cost per mile for my 2013 BRZ vs my wifes 2010 RAV4 (2.5L I4)

Gas in Charlotte, NC for Regular is around 2.07 (gasbuddy.com), Premium is 2.70 on average
I know that all the 15.9 or 13.2 gallons of the tank are not usable, but for the sake of easy comparison I used the full tank capacity for both.

I looked at the estimated MPG for each, even though I know we both get better than that when driving(especially on the highway, I have gotten close to 38 before on long roadtrips with MT)

Anyways, I took a perfect situation when you could consume every last ounce of gas in the tank, and multiplied that by the estimated MPG, to get the total miles per tank possible. Divide that by the cost per gallon, to get these numbers.

Thoughts? Did I totally screw up my logic in how to do the math?

The math has already been done for you.

For your 2013 people average 27.1MPG. at $2.7 per gallon, you are looking at 9.96 cents per mile.

http://www.fuelly.com/car/scion/fr-s

Your math is way off. Cost per mile is just your fillup cost / miles driven, nothing else. So even if I were to use your full tank, $2.7 x 13.2 / 477 = $0.0747

Is this Common Core?

Not to mention a true cost per mile includes other consumables, but that's pedantic...

I've tracked every dollar I've spent on my car since day 1. Price of car, gas, oil changes, taxes, insurance, registration, winter tires, filters, etc.

After slightly under 47,000 miles the car has cost me $0.80 per mile. Total gas mileage average of 30.01 (MT). Assuming a residual value of $16k we're looking at a net price per mile of $0.46. So a little under the government rate.

This is real ^

I get paid mileage for my long trips twice a week and it is paid at the current US average cost of usage which is 58 cents a mile.

I find this is an interesting exercise, but luckily I bought this car for a fun driver and have not had to worry about cost per mile. But it is nice to hear what it is costing me.
well, if I had not modified it and driven it on the track.:)

I've tracked every single tank of gas since purchasing the car too (and for each tank I have the exact price I paid for fuel, the address of the gas station, etc...). If anything I think it's fun to see the trends.
Here's my data, which encompasses everything from road trips, to autocrossing, to snow hooning, etc:

TOTAL: 48,173 miles | 2 yr 7 mo.

MPG: 25.824 (avg), 17.117 (min), 33.979 (max)
$/gal: 3.280 (avg), 2.139 (min), 4.699 (max)

$/mi: 0.127, mi/$: 7.8736

Gal/day: 1.83, $/day: 6.44

Gal/fillup: 9.15, $/fillup: 29.81, Mi/fillup: 236.1, days/fillup: 5.0

FUEL TOTAL: $6,080.35 | 1,866.83 gal

These are just FUEL RELATED costs. Maintenance, modifications, depreciation, tolls, etc... all contribute to total RUNNING COSTS, which are significantly higher.

Keep in mind that estimates of per mile cost are unique to each individual, and that the more you use it, the cheaper it gets. If you drive more, you will be stretching your fixed annual costs like taxes, registration and insurance over more miles, making your per mile cost lower. Additionally, insurance, taxes and registration costs vary depending on who you are and where you live. And there will also be a large difference in maintenance costs depending on whether you do your maintenance yourself or pay someone to do it.

Not if you drive for work or business. Then those costs become very relevant.

----- My fuel metrics -----
(Started tracking since 8/9/14)

64620 -------- Miles Tracked
$2.71 --------- Avg Price/Gallon
$28.60 ------- Avg Price/Fuel-up
$0.105 ------- Avg Price/Mile
$6,777.84 --- Total

Love the rate set by the govt. Whenever I have to go on-site at a client in the tri-state area or even DC and Boston, I just drive even though my company would pay for a flight.

Nice long drive, some alone time with my car, and making .58 cents a mile for those nice highway miles.

I make between $15,000 and $18,000 year just in milage. Seems impressive until you consider my car is now worthless.

It's similar for me. However, I bought the car specifically to use up this way, with the idea that mileage reimbursement would pay my car payment, insurance and fuel costs for the most part. I have to have something to drive and use up anyway, so it might as well be something I like driving. My alternative is for my company to buy me a dumpy economy car that I'll hate.

The fact that it's being used up also has a silver lining. It will long since be paid for at the end of its useful life, so at that point I'll just finance another car to drive for work and keep this one to build out as a weekend/track toy. If it's not worth anything at that point, I won't feel any financial doubts about keeping it.

My exact thoughts. The only difference being that mine will go to my grandson as his first car.