2015 head-to-head · Midsize Car

2015 Buick Regal vs Kia Optima

MPG, range and what each one really costs you to fuel, from official EPA ratings and recalculated with your own gas and electricity prices.

Swap sides
✓ Cheaper to run
$1,938/ year to fuel
24 MPG
✓ Cheaper to run
$1,788/ year to fuel
26 MPG

The 2015 Kia Optima is the cheaper one to run. Driving 15,000 miles a year with $3.10/gal regular gas, it costs about $1,788 a year to fuel (26 MPG), versus $1,938 for the 2015 Buick Regal (24 MPG). That's roughly $149 a year, or about $745 over five years.

Your numbers

Change these to match your driving and local prices. Every figure and chart on this page updates.

Fuel cost over 10 years

  • Buick Regal
  • Kia Optima

Side by side

Buick RegalKia Optima
$1,938 Your annual fuel cost $1,788
24 MPG Combined efficiency 26 MPG
20 MPG City 23 MPG
31 MPG Highway 33 MPG
98 cu ft Passenger volume 102 cu ft
13 cu ft Cargo volume 15 cu ft
372 g/mi Tailpipe CO₂ (g/mi) 334 g/mi
6/10 EPA fuel economy score 7/10
6/10 EPA greenhouse gas score 7/10
Gas Powertrain Gas
Regular gasoline Fuel Regular gasoline
2.0L 4-cyl turbo Engine / motor 2.4L 4-cyl
6-speed manual Transmission 6-speed automatic
FWD Drivetrain FWD

✓ marks the better value. EPA scores run 1–10 (10 is best). Volumes come from the EPA interior volume index and aren't published for every body style.

Buick Regal vs Kia Optima across model years

  • Buick Regal
  • Kia Optima

Annual fuel cost of the most efficient configuration of each model year, at your prices. Click a point to open that year.

How they differ

Per EPA interior volume figures, the Kia Optima has more passenger space (102 vs. 98 cu ft); the Kia Optima has more cargo space (15 vs. 13 cu ft).

Among 69 2015 midsize cars, the Buick Regal ranks 40th and the Kia Optima 33rd for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2015 Buick Regal or the 2015 Kia Optima?

Measured by cost to drive, the Kia Optima. The Buick Regal is rated 24 MPG combined and the Kia Optima 26 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2015 Buick Regal vs. the Kia Optima per year?

At 15,000 miles a year with $3.10/gal regular gas, about $1,938 for the Buick Regal and $1,788 for the Kia Optima.

Which has more cargo space?

The Kia Optima, with 15 cu ft of luggage volume versus 13 cu ft (EPA interior volume index).

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