# Miles per gallon manual calculation vs car calculation **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** prius, toyota\ **Created:** [May 4, 2013, 12:57am UTC](https://community.cartalk.com/t/miles-per-gallon-manual-calculation-vs-car-calculation/79095 "2013-05-04T00:57:19Z")\ **Posts on this page:** 2\ **Page:** 3
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [May 12, 2013, 9:25am UTC](https://community.cartalk.com/t/miles-per-gallon-manual-calculation-vs-car-calculation/79095/41 "2013-05-12T09:25:15Z")
During a discussion on this topic some years back I jotted down some data on an out of state road trip in my prior Lincoln. The results then, as now, show that the dashboard indicator is extremely accurate although I will not claim that every indicator on every car is that way. Note that the dash indicator does not break it down any further than tenths. Home-Goodland, KS 393 miles - 15.1 gallons - actual mileage 26.026 - display 26.1 Goodland - Loveland, CO 226 miles - 8.34 gallons - actual mileage 27.098 - display 27.1 Loveland - Raton, NM 269 miles - 9.96 gallons - actual mileage 27.008 - display 27.0 Raton - Alva, OK 353 miles - 13.66 gallons - actual mileage 25.841 - display 25. 9 The final leg was not notated; it was midnight and I didn’t care at that point. 😉 Usually I don’t resort to jotting this stuff down and most figuring is just done off he top of the head, but in this case I just wanted to satisfy my curiosity and be as precise as possible. The only other instance of writing things down involved a road trip in which I used acetone mixed with gasoline to verify that bunk about fuel mileage increasing because of the use of acetone. Anyhoo, I would say that the dashboard indicators are extremely accurate in my cars and as TwinTurbo mentioned; it kind of keeps me tuned in as to any potential performance drop offs that may not be noticeable. ---
**Author:** ![Triedaq](https://avatars.discourse-cdn.com/v4/letter/t/65b543/32.png) [@Triedaq](https://community.cartalk.com/u/Triedaq)\ **Post date:** [May 12, 2013, 10:06pm UTC](https://community.cartalk.com/t/miles-per-gallon-manual-calculation-vs-car-calculation/79095/42 "2013-05-12T22:06:53Z")
@ok4450–these figures you obtained on your dashboard indicator are accurate enough for me. I don’t need accuracy to the billionth of an mpg. In fact, to the nearest mpg is fine with me. [Previous page](https://community.cartalk.com/t/miles-per-gallon-manual-calculation-vs-car-calculation/79095.md?page=2)