The 2011 Kia Optima has a fuel tank capacity of 17.2 to 18.5 gallons (65–70 liters), depending on the trim. The most common size is 18.5 gallons, used on 5 trims.
A full tank is good for roughly 629–671 highway miles or 407–585 miles around town, going by the EPA ratings.
020 gal40 gal
18.5 gal · Smaller than 59% of 2011 models we list.
Tank figures are the manufacturer's rated capacity, sorted smallest tank first. Range is tank size times EPA city or highway MPG.
How far a 2011 Kia Optima goes on a tank
Gallons left and the distance they cover at each mark on the fuel gauge, at EPA city and highway mileage. At the combined rating of 26 MPG, a full 18.5-gallon tank covers about 481 miles.
Gauge
Gallons
Highway miles
City miles
Full
18.5
629
407
3/4
13.9
472
305
1/2
9.3
315
204
1/4
4.6
157
102
1/8
2.3
79
51
Over 15,000 miles a year (the EPA's yearly estimate) this configuration uses about 577 gallons, roughly 31 full tanks.
Fuel gauges aren't perfectly linear and the low-fuel light comes on with a few gallons still in the tank, so plan your stop before the last eighth.
At 18.5 gallons, the Optima's largest tank ranks second of the seven 2011 sedans compared here. The Nissan Altima Hybrid carries the most (20.0 gal) and the Dodge Avenger the least (16.9 gal).
Other 2011 sedans of a similar size, one model per brand.
2011 Kia Optima fuel system recalls
NHTSA lists 1 fuel-system recall for the 2011 Kia Optima, out of 6 recalls in total. A recall applies only to the vehicles named in it, so check your VIN.
Delivery · Hoses, lines/piping, and fittingsDec 19, 2018 · NHTSA 18V907000 · Kia Motors America · 71,653 vehicles
Kia Motors America (Kia) is recalling certain 2011-2017 Optima, 2012-2017 Sorento and 2011-2018 Sportage vehicles that previously received an engine replacement under recall number 17V-224, warranty, or the Knock Sensor Detection System (KSDS) Product Improvement Campaign. The high pressure fuel pipe that connects to the fuel pump outlet may have been damaged, misaligned or improperly torqued during the engine replacement procedure, possibly causing a fuel leak.
Risk and remedy
Risk: A fuel leak in the presence of an ignition source can increase the risk of a fire.
Remedy: Kia has notified owners, and dealers will inspect and replace the fuel pipe, as necessary, free of charge. The recall began January 17, 2019. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC172.
What is the fuel tank capacity of the 2011 Kia Optima?
The 2011 Kia Optima holds between 17.2 and 18.5 gallons, depending on the trim. 18.5 gallons is the usual size; the smaller 17.2-gallon tank is on the Hybrid 4dr Sedan.
How many gallons and liters does the 2011 Kia Optima gas tank hold?
The 2011 Kia Optima tank holds 65–70 liters, or 17.2–18.5 gallons in US gallons.
Which 2011 Kia Optima has the biggest gas tank?
The 18.5-gallon tank is on the EX 4dr Sedan, EX Turbo 4dr Sedan, LX 4dr Sedan and 2 other trims. The smallest tank, 17.2 gallons, is on the Hybrid 4dr Sedan.
Does the 2011 Kia Optima hybrid have a smaller gas tank?
Yes. Hybrid: 17.2 gal; Gas: 18.5 gal.
How far can a 2011 Kia Optima go on a full tank?
About 629–671 miles on the highway and 407–585 miles in town, going from full to empty at its EPA ratings. Expect less in practice, since nobody runs the tank dry.
How many miles can a 2011 Kia Optima go on a quarter tank?
About 157 highway miles or 102 in town from the 18.5-gallon tank, which has roughly 4.6 gallons left at the quarter mark. Gauges aren't exact, so treat that as a guide.
What gas does the 2011 Kia Optima take?
Regular unleaded. The label inside the fuel door confirms it for your car.
How much does it cost to fill up a 2011 Kia Optima?
At the US average of $4.27 a gallon for regular (EIA, week of October 26, 2026), filling the 18.5-gallon tank from empty costs $78.99. It ranges from $68.45 in the Gulf Coast to $108.96 in California.
How much does a full tank of gas weigh in a 2011 Kia Optima?
About 115 pounds for the 18.5-gallon tank. Gasoline weighs roughly 6.2 pounds a gallon.
Does the 2011 Kia Optima have a bigger gas tank than the Dodge Avenger?
Yes. The 2011 Kia Optima holds up to 18.5 gallons; the 2011 Dodge Avenger holds up to 16.9.
Has the 2011 Kia Optima had a fuel pump or fuel system recall?
Yes. NHTSA lists 1 fuel-system recall for the 2011 Kia Optima: 18V907000 (delivery · hoses, lines/piping, and fittings). Check your VIN at nhtsa.gov/recalls to see if your car is affected.
Sources
Tank sizes: manufacturer-rated capacities from US-market specifications, checked against independent references. Updated October 2026.
MPG and range: EPA ratings (fueleconomy.gov). Range is tank size times EPA MPG.
Fuel prices: U.S. Energy Information Administration, week of October 26, 2026 (this week's prices).