Where our numbers come from
Every number on Milealot comes from a primary source: a U.S. government agency or the carmaker. Here is each source, what we use it for, and how often we check it.
On this page (8 sections)
Mileage rates: IRS and GSA
The IRS standard mileage rate is the amount per mile you can use to deduct business driving on your taxes. Many employers also use it to pay back employees who drive their own cars. We take each rate and its start date from the IRS announcement (a news release or notice) and link to it on the IRS mileage rate page.
The GSA mileage rate is what the federal government pays its employees for driving a privately owned vehicle on official travel. We take it from the U.S. General Services Administration (GSA) and show it on the GSA mileage rate page.
Fuel economy: EPA and fueleconomy.gov
Official fuel economy ratings (the city, highway, and combined MPG on a new car’s window sticker) come from the U.S. Environmental Protection Agency (EPA). We use the data on fueleconomy.gov, which the EPA and the U.S. Department of Energy run together. Your own MPG will differ from the rating, so the MPG calculator works from your own miles and gallons.
Gas prices: EIA
Average U.S. gas prices come from the U.S. Energy Information Administration (EIA), which publishes retail gasoline and diesel prices every week. We use them only as a starting point, for example in the trip gas cost calculator. Enter the price you actually pay for a better answer.
Tires, VINs, and recalls: NHTSA
The National Highway Traffic Safety Administration (NHTSA) is the source for how to read the tire date code (the “DOT” code on the sidewall), which we use in the tire age calculator. NHTSA also runs the official recall database and the vehicle identification number (VIN) decoder, which the Milealot app uses to check your car for open recalls.
Maintenance schedules: owner’s manuals
How often a car needs an oil change, new filters, or other service depends on the make, model, year, and how you drive. The carmaker’s owner’s manual or maintenance schedule is the source we use. We summarize intervals in our own words and name the manual we used. If your manual says something different from our pages, follow your manual. Our car maintenance log has room for the intervals from your manual.
How often we check
| Source | When it changes | When we check |
|---|---|---|
| IRS mileage rate | Usually announced once a year, in December, for the next year. The IRS can also change it mid-year, as it did in 2022. | When the IRS announces a new rate, and at the start of each year |
| GSA mileage rate | Usually at the start of the year, and after IRS rate changes | At the start of each year and when the IRS rate changes |
| EPA fuel economy | As new model years are tested | Before each update of our car data |
| EIA gas prices | Every week | When we update the default prices in our calculators |
| NHTSA tire and recall information | Recalls are added as they are issued | The app checks recalls for your car; site pages are checked when we update them |
| Owner’s manuals | With each model year | When we write or update a page |
Each page shows the date we last checked its sources. If you see an outdated number, please tell us.
Licenses and reuse
- U.S. government data. Works created by the U.S. federal government, including data from the IRS, GSA, EPA, EIA, and NHTSA, are not protected by copyright in the United States (17 U.S.C. § 105). We still name the source on every page that uses it, and the EIA asks that its data be credited.
- Owner’s manuals. Owner’s manuals belong to the carmakers. We don’t copy them; we summarize intervals in our own words and name the source.
- Our pages and logs. The text, calculators, and design of this site belong to Milealot. You are welcome to print and use our logs for your own records. Other terms are in our terms of use.