Nothing on this page is typed in. Every number is computed from the log when the site builds, so it moves the moment a tank is added. Averages that would rest on fewer than 5 tanks are left blank rather than stated.
The price of a gallon, 2013 to 2026
Total paid divided by gallons pumped, one dot per fill-up, colored by car. Diesel for the Golf, regular gasoline for the rest.
$1.53
Cheapest gallon
May 19, 2020, 2017 Honda Fit
$4.46
Priciest gallon
June 30, 2022, 2017 Honda Fit
$1.98
Cheapest year
2020 average over 22 tanks
$3.89
Priciest year
2013 average over 27 tanks
$2.89
All-time average
mean of 302 tanks; $2.94 as total dollars over total gallons
Price by month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
2013
4.00
4.08
4.00
3.85
3.80
3.80
3.85
3.90
3.90
3.90
3.90
3.84
2014
3.70
3.73
3.85
3.85
3.83
3.72
3.67
3.66
3.59
3.49
3.32
3.18
2015
2.60
2.76
2.65
2.60
2.77
2.66
2.61
2.55
2.43
2.40
2.39
2.28
2016
2.06
1.90
1.98
2.09
2.23
2.36
2.28
2.28
2.30
2.31
2.34
2.40
2017
2.29
2.51
2.37
2.21
2.21
2.14
2.16
2.25
2.70
2.39
2.42
2.28
2018
2.46
2.37
2.44
2.56
2.72
2.71
2.69
2.72
2.75
2.78
3.06
2.00
2019
2.07
2.11
2.29
2.70
2.64
2.46
2.55
2.40
2.53
2.46
2.35
2020
2.31
2.13
1.99
1.53
1.90
1.96
1.97
1.96
1.97
1.98
1.96
2021
2.15
2.24
2.64
2.61
2.52
2.89
2.93
2.98
2.95
3.10
3.19
3.12
2022
3.14
3.32
4.24
3.93
3.92
4.46
4.20
3.54
3.30
3.22
3.14
2.88
2023
3.00
3.30
3.26
3.22
3.29
3.22
3.27
3.99
3.38
3.07
2.80
2.99
2024
2.75
2.94
3.33
3.41
3.39
4.11
2.94
2.47
2.90
2.91
2025
2.97
3.14
3.06
3.15
2.99
2.82
2.98
2.87
2.72
2.82
2026
2.56
2.66
3.45
3.65
3.94
3.55
3.70
3.80
3.92
3.80
$1.53$4.46average price per gallon in that month; brighter is pricier; diesel through early 2017
January
Cheapest month of the year
$2.67 average over 26 tanks since 2013
May
Priciest month of the year
$3.04 average over 26 tanks
Every tank since 2013 grouped by calendar month, all years together. The gap between the two months is what seasonal blending and summer demand look like from one household's receipts.
How much driving
Miles logged in the year divided by the days those tanks covered. The first tank of each car counts its days from the purchase date.
41.0 miles a day in 2014, 11.0 in 2024
The busiest and quietest full years in the log. The slide starts in 2016, the year the notes record a new job.
51 days without a fill-up in spring 2020
The longest gap of that year ended May 19, 2020, at $1.53 a gallon. The pandemic shows up in a fuel log as silence.
Habits
Saturday is the most common fill-up day (51 tanks); Tuesday the least (35). Counted from the date of every tank in the log.
How low the tank goes
Car
Tank
Typical fill
Deepest fill
Left at a typical fill
Full-tank range
2012 Volkswagen Golf TDI
14.5 gal
13.0 gal (90%)
13.84 gal (95%)
1.5 gal (56 mi)
541 mi
2013 Honda Fit
10.6 gal
8.3 gal (78%)
9.10 gal (86%)
2.3 gal (70 mi)
320 mi
2017 Honda Fit
10.6 gal
7.8 gal (74%)
8.70 gal (82%)
2.8 gal (97 mi)
366 mi
2023 Toyota Corolla
13.2 gal
9.0 gal (68%)
10.40 gal (79%)
4.2 gal (140 mi)
441 mi
95% of the tank in one fill
The deepest fill in the log: 13.84 gallons into the 2012 Volkswagen Golf TDI's 14.5 gallon tank on December 21, 2016 (Deep freeze). As a habit, the 2012 Volkswagen Golf TDI was run the lowest, a typical fill covering 90% of its tank.
Rated capacities verified by the owner. Every fill is treated as a fill to full, so gallons pumped is what was missing; the fuel left and the range are estimates from the rated capacity and the car's median MPG, not gauge readings.
What it costs
Dollars spent on fuel per calendar year, every car combined.Running total of fuel spend from January 1, one line per year, every car together. 2026 in blue, 2025 in white, 2013 to 2024 in gray behind them. Hover any line for the total on that date.
$84 ahead of 2025
2026 had spent $389.05 on 13 tanks by October 9. 2025 stood at $304.67 on October 4 and finished at $411.93 over 15 tanks.
Fuel cost per mile over each car's whole record: total dollars divided by total miles. Fuel only; no maintenance, insurance or depreciation.
Mileage
Mean of the per-tank MPG figures for each car. Hover a bar for the overall miles-per-gallon ratio, which weights big tanks more.
42.1MPG
Best tank ever
2012 Volkswagen Golf TDI, October 21, 2013, 533 miles (Ultra conservative driving habits)
28.1MPG
Worst tank
2013 Honda Fit, May 24, 2017
533mi
Longest tank
2012 Volkswagen Golf TDI, October 21, 2013
13.84gal
Biggest fill
2012 Volkswagen Golf TDI, December 21, 2016
$53.09
Priciest fill
2012 Volkswagen Golf TDI, October 4, 2013
52days
Longest gap
ending July 12, 2024, 2023 Toyota Corolla
Temperature and mileage
Each tank against the mean temperature over the days it was driven, measured at Atlanta. One panel per car, because every car has its own MPG baseline; the dashed line is a straight fit.
+0.2 MPG per 10°F, a small effect
The fitted slopes averaged across cars, weighted by tank count. It is not the same car to car: the 2023 Toyota Corolla moves the most at +0.6 MPG per 10°F, the 2012 Volkswagen Golf TDI barely at all at +0.1. Temperature explains at most 11% of the tank-to-tank variation in any car; trips, traffic and how full the tank was matter more.
2012 Volkswagen Golf TDI
100 tanks. Fitted: +0.1 MPG per 10°F, r = 0.08.
2013 Honda Fit
78 tanks. Fitted: -0.3 MPG per 10°F, r = -0.23.
2017 Honda Fit
72 tanks. Fitted: +0.4 MPG per 10°F, r = 0.25.
2023 Toyota Corolla
52 tanks. Fitted: +0.6 MPG per 10°F, r = 0.33.
Car
Cold, under 50°F
Mild, 50 to 75°F
Warm, over 75°F
2012 Volkswagen Golf TDI
36.5 (27)
37.2 (52)
36.8 (21)
2013 Honda Fit
31.2 (14)
30.4 (43)
30.2 (21)
2017 Honda Fit
33.5 (19)
34.7 (40)
35.0 (13)
2023 Toyota Corolla
31.9 (12)
33.5 (27)
34.4 (13)
Average tank MPG by temperature band, tank counts in parentheses, blank under 5 tanks. A tank's temperature is the mean of the daily means from the day after the previous fill through the fill day, and needs 80% of those days on record. Weather data by Open-Meteo (ERA5 reanalysis, Atlanta grid point), 100% of tanks covered.
Seasons
Car
Winter
Spring
Summer
Fall
2012 Volkswagen Golf TDI
36.4 (27)
36.8 (26)
36.8 (25)
37.9 (22)
2013 Honda Fit
31.1 (15)
30.5 (21)
30.0 (24)
30.5 (18)
2017 Honda Fit
33.5 (22)
34.4 (18)
34.8 (16)
35.3 (16)
2023 Toyota Corolla
32.0 (13)
33.7 (13)
34.7 (15)
32.8 (11)
Average tank MPG by season, with the tank count in parentheses. Winter is December to February. A cell shows only the count when a season has fewer than 5 tanks for that car. The old notes column already suspected this: "Winter Storm" and "Hot > 90" sit next to tanks in 2014 and 2016.
Winter gas and mileage
From June 1 to September 15, stations must sell summer gas, made to evaporate less in the heat. The rest of the year they sell winter gas, which carries more butane and, by the figure usually quoted from a 1995 EPA study, 1.7% less energy per gallon. If the blend matters, tanks burning summer gas should beat tanks burning winter gas at the same temperature.
-0.3%
Summer gas against winter gas
average tank MPG with car, temperature and pace held level; 202 tanks
+3.2%
Largest gain the log allows
top of the 95% range, about 1.0 MPG; the bottom is -3.6%
5.0%
Smallest gain it can detect
about 1.6 MPG; a true gain this size shows up four times in five
1.7%
The textbook gap
less energy in winter gas (EPA, 1995), about 0.6 MPG here
No difference this log can see
With the car, the tank's temperature and its miles per day held level, summer gas came out at -0.3% against winter gas, and the 95% range runs from -3.6% to +3.2%. A summer-gas gain above 1.0 MPG is ruled out. The textbook 1.7% is too small for this log to settle: one tank still scatters by 5.6% after all of that, so it takes a difference near 5.0% to stand out reliably.
Every gasoline tank, placed on the calendar by the day its fuel was bought (a tank burns what the previous fill put in), against its own car's average tank MPG, before temperature is accounted for. The shaded span is the summer-gas window. The white line averages the tanks within 15 days either side of each date, every year together; over the year it swings 4.6 points, against the 1.7 the textbook gap would add inside the band.
Summer gas comes with summer weather
Tanks on summer gas were driven at a median 77°F, tanks on winter gas at 55°F. Of the 86 tanks driven at 68°F or warmer, 25 burned winter gas, and every one of those had its fuel bought between April 1 and May 31 or between September 16 and October 31, while the pumps were partway between the two blends. Warm weather on full winter gas, the one comparison that would pull the two apart, never happens here.
The estimate is a least-squares fit of log tank MPG on the car, the tank's mean temperature (as a curve), its miles per day and a summer-gas flag, with robust standard errors, over 202 tanks from 2017 to 2026: every gasoline tank of 4 gallons or more with a temperature on record, 62 of them on summer gas. The 2012 Volkswagen Golf TDI is left out: it burned diesel, and the switch is a gasoline rule. The summer window is EPA's; in the Atlanta area its limit was eased from 7.8 to 9.0 psi in 2020, which brings summer gas a little closer to winter gas.