Kia Rio vs Lexus IS: Specs Compared

Also searched as Lexus IS vs Kia Rio specs — both orientations show this same side-by-side comparison.

The Kia Rio is the more efficient of the two: it reaches 36 mpg combined versus 26 mpg for the Lexus IS, a 10 mpg advantage and costs about $1,200 less per year to fuel.

Across 5 measured categories, the Kia Rio leads in 5. Figures are EPA test data, not manufacturer claims.

2015–2023

Kia Rio

Compact Cars · 17 configurations

36mpg combined (best)
All Kia Rio specs

2015–2026

Lexus IS

Compact Cars · 52 configurations

26mpg combined (best)
All Lexus IS specs

Head-to-head specifications

MetricKia RioLexus IS
Best combined MPG36 mpg ✓26 mpg
Best city MPG33 mpg ✓22 mpg
Best highway MPG41 mpg ✓32 mpg
Lowest annual fuel costEPA estimate at 15,000 miles per year$1,700 ✓$2,900
Lowest CO2 output249 g/mi ✓345 g/mi
Engines offered1.6, SIDISIDI & PFI, SIDI
TransmissionsAutomatic (AV-S1), Automatic (variable gear ratios), Automatic (S6)Automatic (S6), Automatic (S8)
DrivetrainsFront-Wheel DriveAll-Wheel Drive, Rear-Wheel Drive
Fuel typesRegularPremium
EPA classCompact CarsCompact Cars
Years covered2015–20232015–2026
Configurations on record1752

Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.

Kia Rio vs Lexus IS dimensions and size

The Lexus IS is 25.6 inches longer than the Kia Rio on a wheelbase 8.7 inches longer, and 1,364.7 lbs heavier. Both clear the roughly 200 inches of usable length in a standard single garage bay.

Kia Rio versus Lexus IS exterior dimensions
DimensionKia Rio (2024)Lexus IS (2026)Difference
Length160.2 in185.8 in25.6 in
Width (excl. mirrors)68.1 in72.4 in4.3 in
Height57.1 in56.3 in0.8 in
Wheelbase101.6 in110.2 in8.7 in
Curb weight2,549 lbs3,913 lbs1,365 lbs

Width excludes mirrors; add 8–12 inches for mirrors out. Figures are for the newest model year on record for each vehicle. See both drawn to scale.

Kia Rio vs Lexus IS: what the numbers mean

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Kia Rio burns about $1,700 of fuel annually against $2,900 for the Lexus IS. That $1,200 yearly gap compounds to roughly $6,000 over five years and $9,600 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.

City and highway economy: the Kia Rio leads in both cycles — 33 mpg city and 41 mpg highway against 22 and 32 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Kia Rio is recorded with 2 distinct engine configurations (1.6, SIDI), the Lexus IS with 2 (SIDI & PFI, SIDI). Across 17 recorded Kia Rio configurations and 52 for the Lexus IS, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.

Drivetrain and class: the Kia Rio is offered with Front-Wheel Drive, the Lexus IS with All-Wheel Drive, Rear-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Compact Cars and Compact Cars respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the Kia Rio emits 249 g/mile of CO2 versus 345 g/mile for the Lexus IS. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.

Rio vs IS: common questions

Which is better on gas, the Kia Rio or the Lexus IS?

The Kia Rio is the more efficient of the two: it reaches 36 mpg combined versus 26 mpg for the Lexus IS, a 10 mpg advantage and costs about $1,200 less per year to fuel.

Which costs less to run per year?

By EPA estimates at 15,000 miles a year, the Kia Rio runs about $1,700 a year in fuel at its most efficient configuration, versus about $2,900 for the Lexus IS — a difference of roughly $1,200 per year.

What engines do the Rio and IS offer?

Kia Rio: 1.6, SIDI. Lexus IS: SIDI & PFI, SIDI.

Are they in the same vehicle class?

Yes — the EPA classifies both the Kia Rio and the Lexus IS as Compact Cars, so they compete directly.

More Rio comparisons

More IS comparisons

Comparison id: kia-rio-vs-lexus-is