How Much Gas Does Idling Use? Cost per Hour

Idling burns a quarter to a half gallon of gasoline an hour, according to fueleconomy.gov, which at the EIA's U.S. regular price of $4.153 a gallon (week of November 2, 2026) costs $1.04 to $2.08 an hour, or 1.7 to 3.5 cents a minute.

The best-measured single figure comes from Argonne National Laboratory, which ran a 2011 Ford Fusion with a 2.5 liter engine on a direct fuel flow meter and recorded 0.279 cubic centimeters of gasoline per second at idle. That is 0.265 gallons an hour, or $1.10 at $4.153. Ten seconds of it costs 0.31 cents, so the saving from shutting the engine off for one short stop is a fraction of a cent. The cost shows up in the habit: twenty minutes a day at that rate is 32.3 gallons and $134.07 a year.

Engine size moves the bill more than geography does. Argonne's light-duty worksheet runs from 0.16 gallons an hour for a 1 liter engine to 0.79 for a 5 liter engine, a factor of 4.9, while the highest regular price in the EIA's weekly state series (California, $5.748) is 1.61 times the lowest (Texas, $3.578). A 0.63 gallon-an-hour engine idling in Texas costs $2.25 an hour; a 0.32 gallon-an-hour engine in California costs $1.84.

A 2.5 liter sedan on a fuel flow meter

The Argonne handout "Which Is Greener: Idle, or Stop and Restart?" (L. Gaines, E. Rask and G. Keller, funded by the DOE Clean Cities program) describes its test car as a 2011 Ford Fusion mid-sized sedan with a 2.5 liter four-cylinder engine rated at 175 horsepower, a six-speed automatic and an EPA label of 23 miles per gallon city, 33 highway and 26 combined. The work was done in a test cell at Argonne's Advanced Powertrain Research Facility under approximate Federal Test Procedure ambient conditions, with a direct fuel flow meter for fuel and an emissions analyzer for exhaust. Its Table 1 gives idling fuel as 0.279 cubic centimeters per second, and the text puts the ambient temperature at 21 C.

The rate sits near the bottom of the range Argonne reports for passenger cars. Its conclusions state: "Idling fuel usage varies from 0.2 to 0.5 gal/h for passenger vehicles across a range of sizes, and increased with idling speed." The same range appears on the October 17, 2012 DEER presentation slide that preceded the handout, while fueleconomy.gov separately says idling "can use a quarter to a half gallon of fuel per hour, depending on engine size and air conditioner (AC) use." The Fusion's 0.265 gallons an hour is a measurement of one car; the two ranges are statements about passenger cars in general.

Argonne is plain about how far one car stretches. The handout's research limitations read: "Data presented here are based on one vehicle at one temperature, with a small number of runs. Therefore, although several conclusions are suggested by this work, generalizations are unwarranted without additional work to confirm the extent to which the results apply, for the following reasons:" The reasons listed are that hot and cold ambient conditions are likely to affect results, as are the loads required to supply passenger comfort at those temperatures, and that older vehicles and diesels are both likely to behave differently. Every dollar figure below therefore comes with an engine, a source and a date, and none is a forecast for a particular driver's car.

About ten seconds of fuel

The handout's Figure 3 plots the idling fuel rate against the fuel burned when the engine is restarted and marks the restart at 10.1 seconds. The shaded area under the idle line before that point is the fuel the engine would have burned idling instead of being off, and the shaded area between the two lines after the restart is the excess the restart costs. The written conclusion is that idling for more than 10 seconds uses more fuel and emits more carbon dioxide than restarting.

The handout prints no restart quantity in cubic centimeters. As an approximation derived here, set the restart penalty equal to about 10 seconds of idling at the Table 1 rate: 0.279 cc per second times 10.1 seconds is 2.82 cc, about 0.57 of a U.S. teaspoon, or 0.00074 gallons. At $4.153 a gallon that is 0.31 cents. A restart, in fuel terms, costs less than a third of a cent. That smallness is why the rule is stated in seconds: the saving starts after the first few seconds of a stop, and then it accumulates at roughly 1.8 cents for each full minute the engine stays off.

The worksheet's rule of thumb: about 0.16 gallons an hour per liter

A second Argonne document gives idle fuel use by engine size. The light-duty idling worksheet ("How Much Could You Save by Idling Your Light-Duty Vehicle Less?", Wayback copy, saved February 18, 2013) prints a five-row table of idling fuel use "no accessories" for engines of 1 to 5 liters. Dividing each row by its displacement shows how regular it is.

The rate per liter stays between 0.158 and 0.160 gallons an hour across all five rows, which makes the table close to a straight line: every liter of displacement adds about 0.16 gallons an hour at idle. The table does not name a vehicle behind any row or say what temperature the numbers refer to, and the five values are rounded, so it works as a rule of thumb for scale. The 1 liter row (0.16) sits below Argonne's 0.2 to 0.5 range, the 2 and 3 liter rows (0.32 and 0.48) sit inside it, and the 4 and 5 liter rows (0.63 and 0.79) sit above it. Neither range is a limit on what an engine can burn.

The same sheet lists seven example vehicles with their engine sizes. Interpolating the worksheet rate between its whole-liter rows places each of them on the table, with one exception: the 6.2 liter Corvette is beyond the 5 liter top row, and the sheet gives no rate for it.

The Fusion is the instructive row. The worksheet's straight line puts a 2.5 liter engine at 0.40 gallons an hour, and Argonne's own direct measurement of a 2.5 liter Fusion came to 0.265, which is 34 percent lower. Neither document explains the difference. What it changes is the price column: a reader who prices a 2.5 liter car from the worksheet gets $1.66 an hour, and one who prices it from the measurement gets $1.10. Both come from the same laboratory, and the spread between them is a fair picture of the uncertainty in any single idle figure.

Argonne's later two-page worksheet (Wayback copy, saved September 19, 2025) lists cars by name instead. It gives the 2.0 liter Ford Focus 0.16 gallons an hour with no load and 0.29 with load, and the 4.6 liter Ford Crown Victoria 0.39 and 0.59, which are 81 percent and 51 percent more under load. The worksheet attaches its footnotes (high idle, power take-off, air conditioning) to its truck rows only, so the "with load" column for the cars is unexplained, and the two loaded rates appear below exactly as printed with no more claimed for them.

Dollars per hour, from 0.16 to 0.79 gallons

The price of an idling hour is the rate times the price per gallon, and the rates above span a factor of five. Table 4 sorts every rate used on this page from lowest to highest and prices each at the EIA's U.S. regular average for the week of November 2, 2026, with the reading a week earlier ($4.269, week of October 26) alongside.

Every extra tenth of a gallon an hour adds $0.42 to the hour at $4.153. That makes the cheapest row ($0.66) and the dearest ($3.28) $2.62 apart for the same hour of sitting still. The retail price fell $0.116 between the two weeks shown, 2.7 percent, and every row falls by the same percentage with it: the band's hour was $1.07 to $2.13 at the October 26 reading. The weekly price series moves by cents; the rate moves by multiples, and the rate is the part most price-per-hour claims leave unstated. The national price is itself a choice: EIA, AAA and the BLS each build a different one, as the comparison of AAA and EIA gas price averages shows.

Nine states with a weekly series, plus the U.S. average

EIA publishes weekly retail regular gasoline prices for the United States, regional groupings, nine states and ten cities. The states are California, Colorado, Florida, Massachusetts, Minnesota, New York, Ohio, Texas and Washington, and they are the only states in Table 5; the other 41 states and the District of Columbia have no weekly EIA series and are not in it. The dollar columns use the November 2 week, the newest in EIA's release of November 3; the state table of gasoline use per driver prices the October 26 week, so the two pages differ by the Change column. The dollar columns apply four rates: 0.25 and 0.50 gallons an hour (the fueleconomy.gov band), 0.32 (Argonne's 2 liter worksheet row) and 0.63 (its 4 liter row).

California's $5.748 is 1.61 times Texas's $3.578, a gap of $2.170 a gallon. At half a gallon an hour that is $1.09 an hour, and at a quarter gallon it is $0.54. Engine size beats the state: a 0.63 gallon-an-hour engine in Texas ($2.25) costs more to idle than a 0.32 gallon-an-hour engine in California ($1.84). Washington follows California at $5.095, and the six states from New York at $4.217 down to Florida at $3.791 sit within $0.426 of each other, so their idling hours differ by about $0.21 even at the top of the band.

One week can reorder the middle of the table. Colorado fell 8.7 percent between October 26 and November 2, from $4.458 to $4.068, moving from third highest of the nine to sixth, and Ohio fell 6.6 percent, from $4.380 to $4.090. The U.S. average moved 2.7 percent. Idling costs follow the pump price one for one, so a dollar-an-hour figure built on a single week is a snapshot, and the date it was taken is part of the number. The tax and supply reasons behind the spread are in why gas prices differ by state, and the PetroEyes city gas price map carries city-level prices.

What one stop costs

Idling comes in minutes, not hours. Table 6 prices stops of 10 seconds to an hour at the Fusion's measured rate, at Argonne's 2 liter worksheet rate and at the top of the band, using the U.S. price of $4.153. The first column also gives the Fusion's fuel in cubic centimeters, the unit Argonne measured in.

A dollar buys 54 minutes of idling at the Fusion's rate and 29 minutes at the top of the band. Five minutes costs 9.2 cents to 17.3 cents, ten minutes 18.4 cents to 34.6 cents. The 10 second line shows why the rule is so easy to ignore: 0.31 cents at the Fusion rate and 0.58 cents at the band top are the cost of 10 seconds of idling, which on the restart approximation above is about the cost of one restart.

Turning the engine off: what the federal text says

Three federal statements carry the guidance, and they answer slightly different questions. Argonne's handout answers a fuel and carbon dioxide question about one car: idling for more than 10 seconds uses more than restarting. The Clean Cities fact sheet "Idling Reduction for Personal Vehicles", prepared by Argonne in May 2015 (Wayback copy, saved April 12, 2026), turns that into advice, and fueleconomy.gov adds a cost-and-starts rule with its own thresholds. Table 7 sets the statements side by side with the exact wording.

fueleconomy.gov ties its one-minute figure to the limit of about 10 starts a day and does not say why it is a minute and not 10 seconds; Argonne's and the fact sheet's 10 seconds are statements about fuel and emissions. The same fueleconomy.gov passage adds that occasionally exceeding 10 starts "should not cause excessive starter wear", and the fact sheet states that "today's gasoline and diesel vehicles do not suffer damage by being turned on and off" and that starters and batteries are much more durable than they used to be. None of the sources puts a dollar figure on starter or battery wear, so none is included in the arithmetic here.

Within those statements the fuel arithmetic is short. A driver who keeps to the 10-starts-a-day guidance and spends 20 minutes a day with the engine off, in 10 shutdowns, avoids 1,200 seconds of idling and pays for 10 restarts at about 10.1 seconds each. The net is 1,099 seconds of idling a day, which at the Fusion's rate is 29.6 gallons a year: $123 at $4.153, $170 at California's $5.748 and $106 at Texas's $3.578. The same sum describes a car with a start-stop system that stops the engine at 10 stops totalling 20 minutes a day, if its restart costs about what Argonne's key-start did, which the sources do not say. The fact sheet says stop-start technology "also eliminates idling when the car is stopped".

Heat, air conditioning and the loaded hour

Argonne lists "the loads required to supply passenger comfort" at hot and cold temperatures among the reasons its single-car result cannot be generalized, and fueleconomy.gov names air conditioner use as one of two drivers of idle fuel (engine size is the other). Neither prints a rate for a gasoline car with the A/C on, by engine size. What fueleconomy.gov does print is a cost per minute at an assumed $4.28 a gallon: $0.02 to $0.03 a minute with the A/C off and $0.03 to $0.05 with it on. Dividing by the price and multiplying by 60 turns those into the gallons an hour they imply.

The A/C-off range, 0.28 to 0.42 gallons an hour, sits just above Argonne's Fusion measurement (0.265) and brackets the 2 liter worksheet row (0.32), so the tips page and the laboratory table cover the same ground. The A/C-on range, 0.42 to 0.70, reaches above the half-gallon top of the same page's text. fueleconomy.gov does not reconcile the two, and the rounding margin of about 0.07 gallons an hour covers only part of the 0.20 gallon difference at the top. For a budget, the practical reading is that a hot day or a cold morning with the climate control working can push an idling hour from the $1.04 to $2.08 band toward the top of it or beyond, at $4.153.

Cold weather adds one more entry that is not about fuel rate. fueleconomy.gov's cold-weather page says that warming a vehicle up before a trip lowers fuel economy and that "idling gets 0 miles per gallon", and the fact sheet notes the winter exception for defrosting windows and the inspection-station exception, where a station may require the engine to idle to keep it at operating temperature. Those are statements about when idling is unavoidable, and the cost tables apply to them the same way: a 10 minute defrost at the Fusion's rate burns 0.044 gallons, 18.4 cents at $4.153.

Idling by the year: 5 to 60 minutes a day

Table 9 multiplies fueleconomy.gov's quarter-to-half-gallon band by a daily idle time and 365 days, then prices the gallons at the U.S. average, at California's price and at Texas's. The 6 minute row is the figure Argonne's handout uses for its national estimate. The ranges run from the band's low end to its high end, so a car at the Fusion's 0.265 gallons an hour lands near the bottom of each one.

The gallons scale in a straight line with minutes, so any other habit can be read off the table by proportion. A school pickup line of 15 minutes is 1.5 times the 10 minute row. At 20 minutes a day, a car idling at the band's ends uses 30.4 to 60.8 gallons a year, the equivalent of 791 to 1,582 miles of driving at the Fusion's 26 mpg. At an hour a day, the range reaches $379 to $758 a year at the U.S. price, and a Californian at the top of the band spends $1,049. The state price matters less than the minutes: the whole California-versus-Texas gap on the 20 minute row at the band high is $132 a year, while doubling the idle time doubles the bill in either state.

Checking the 3 billion gallon claim

Argonne's handout opens its case with a national figure: "If each car in the United States idles just 6 minutes per day, about 3 billion gallons of fuel are wasted annually, costing drivers $10 billion or more." The handout does not say how many cars it counted. The Clean Cities fact sheet, from the same laboratory, gives "the 250 million personal vehicles in the U.S." and states that personal-vehicle idling wastes about 3 billion gallons a year, and the Alternative Fuels Data Center says roughly half of the more than 6 billion gallons that idling wastes across all vehicle types is attributable to passenger vehicles. Combining the two documents gives an idle rate that can be compared with the tables above.

The claim works out to 12.0 gallons per vehicle a year and an implied idle rate of 0.329 gallons an hour. That lands inside the 0.2 to 0.5 band and next to the 2 liter worksheet row (0.32), which is in line with the laboratory figures for a 2 liter engine. The dollar figure implies $3.33 a gallon, and the handout says "or more"; at the EIA's $4.153 for the week of November 2, 2026, the same 3 billion gallons would cost $12.46 billion. The 6 minutes is a fleet average, so it includes vehicles that never idle and ones that idle for hours.

Idling against driving: minutes per mile

Fuel economy puts idling on a scale that drivers can feel. The Fusion's EPA combined label of 26 miles per gallon is 0.0385 gallons a mile, which at $4.153 is 16.0 cents a mile. Its idle rate of 0.265 gallons an hour burns that much fuel in 8.7 minutes, so each 8.7 minutes of idling uses the fuel of a mile of combined driving, and an hour of idling uses the fuel of about 6.9 miles. A 10 minute wait in a parking lot is worth 1.15 miles of fuel; a daily 20 minutes is 2.3 miles of fuel every day, or 839 miles a year. The comparison uses the label's combined figure, and real fuel use per mile varies with speed, so it is a scale marker and not a conversion.

Idling also pulls down the miles per gallon of the trip around it. fueleconomy.gov's cold-weather page puts it as "idling gets 0 miles per gallon". Take a 26 mile trip at the label's 26 mpg, which uses 1.000 gallon, and add 10 minutes of idling first at the Fusion's rate: the fuel becomes 1.044 gallons and the trip's miles per gallon falls to 24.9, 4.2 percent lower, with no change in how the car was driven.

How old the figures are, and one DOE chart that disagrees

The measurements behind this page are older than the prices. The Fusion is a 2011 model tested in 2012 and described in a 2013 handout. The by-liter worksheet was captured in February 2013 and lists model-year 2010 and 2011 example vehicles. The later worksheet cites an Argonne conventional-vehicle study presented on December 2, 2012 for its car rows. Argonne's own conclusion that older vehicles and diesels are likely to behave differently applies the other way as well: this page has no measurement of a recent turbocharged or hybrid engine, and no rate from any source for a car with a stop-start system at rest.

The DOE's Fact of the Week 1239 (May 23, 2022) restates the 10 second result and notes that fuel used when idling "varies by the amount of heat/air used, accessories used (radio, lights, and fans), vehicle make and model, ambient conditions, and many other factors." Its chart, "Fuel Use for Idling versus Restarting Engine", shows 10.2 cubic centimeters for a restart and 11.3 for 10 seconds of idling. Eleven point three cubic centimeters in 10 seconds is 1.13 cc per second, about 1.07 gallons an hour, which is roughly 4.1 times Argonne's Table 1 and outside Argonne's 0.2 to 0.5 band. The direction of the chart matches the handout, with the restart costing less than 10 seconds of idling, but its scale does not, so this page uses the handout's own figures throughout.

The EIA series used here is the weekly retail regular series as released on November 3, 2026, which carries the week of November 2, its newest reading, and the week of October 26 before it. For a longer view of the price itself, our gas prices by year, adjusted for inflation shows where $4.153 sits against 1978 to 2025.

Pricing your own idle minute

The formula is one line: gallons per hour times the price per gallon, divided by 60 for a minute. For a 3.6 liter engine, such as the 2010 Chevrolet Malibu in Argonne's example list, the interpolated worksheet rate is 0.57 gallons an hour. In New York at $4.217 that is $2.40 an hour and 4.0 cents a minute, and Table 6 or Table 9 scale it by proportion. The rate is the uncertain input: replace the worksheet's value with the idle figure for your own engine if you have one, and use the weekly price from the PetroEyes gas price page or the EIA's state series for the price. For the gallons a year that a driver in each state burns while moving, our gasoline use per driver by state table gives dollars per driver at the October 26 price, and why gas prices differ by state explains the price gaps that Table 5 shows.

Data and sources, all checked November 3, 2026: Argonne National Laboratory, Which Is Greener: Idle, or Stop and Restart? (L. Gaines, E. Rask and G. Keller, 2013 handout hosted by the Alternative Fuels Data Center) and the DEER 2012 presentation P-09 (October 17, 2012). Argonne, How Much Could You Save by Idling Your Light-Duty Vehicle Less? (Wayback copy, saved February 18, 2013) and the Idling Reduction Savings Calculator worksheet (Wayback copy, saved September 19, 2025). U.S. Department of Energy, Clean Cities and Alternative Fuels Data Center, Idling Reduction for Personal Vehicles (Argonne, May 2015; Wayback copy, saved April 12, 2026) and Idle Reduction. fueleconomy.gov, Fuel Economy Tips and Cold Weather Tips. DOE Vehicle Technologies Office, Fact of the Week 1239 (May 23, 2022). U.S. Energy Information Administration weekly retail regular gasoline prices (release of November 3, 2026): U.S., California, Washington, Colorado, Ohio, New York, Minnesota, Massachusetts, Florida and Texas. Conversions, per-hour and per-year costs and the restart approximation are calculated from those inputs.