Cadillac CT5 vs Lexus RC: Specs Compared

Also searched as Lexus RC vs Cadillac CT5 specs — both orientations show this same side-by-side comparison.

The Cadillac CT5 is the more efficient of the two: it reaches 27 mpg combined versus 26 mpg for the Lexus RC, a 1 mpg advantage and costs about $100 less per year to fuel.

Across 5 measured categories, the Cadillac CT5 leads in 5. Figures are EPA test data, not manufacturer claims.

2020–2026

Cadillac CT5

Midsize Cars · 52 configurations

27mpg combined (best)
All Cadillac CT5 specs

2015–2025

Lexus RC

Subcompact Cars · 50 configurations

26mpg combined (best)
All Lexus RC specs

Head-to-head specifications

MetricCadillac CT5Lexus RC
Best combined MPG27 mpg ✓26 mpg
Best city MPG23 mpg ✓22 mpg
Best highway MPG33 mpg ✓32 mpg
Lowest annual fuel costEPA estimate at 15,000 miles per year$2,800 ✓$2,900
Lowest CO2 output333 g/mi ✓345 g/mi
Engines offeredSIDISIDI & PFI
TransmissionsAutomatic (S10), Manual 6-spdAutomatic (S6), Automatic (S8)
DrivetrainsAll-Wheel Drive, Rear-Wheel DriveAll-Wheel Drive, Rear-Wheel Drive
Fuel typesPremiumPremium
EPA classMidsize CarsSubcompact Cars
Years covered2020–20262015–2025
Configurations on record5250

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

Cadillac CT5 vs Lexus RC dimensions and size

The Cadillac CT5 is 8.7 inches longer than the Lexus RC on a wheelbase 8.7 inches longer, and 92.6 lbs lighter. Both clear the roughly 200 inches of usable length in a standard single garage bay.

Cadillac CT5 versus Lexus RC exterior dimensions
DimensionCadillac CT5 (2026)Lexus RC (2026)Difference
Length193.7 in185 in8.7 in
Width (excl. mirrors)74 in72.4 in1.6 in
Height57.1 in55.1 in2 in
Wheelbase116.1 in107.5 in8.7 in
Curb weight3,799 lbs3,891 lbs93 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.

Cadillac CT5 vs Lexus RC: what the numbers mean

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Cadillac CT5 burns about $2,800 of fuel annually against $2,900 for the Lexus RC. That $100 yearly gap compounds to roughly $500 over five years and $800 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 Cadillac CT5 leads in both cycles — 23 mpg city and 33 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 Cadillac CT5 is recorded with 1 distinct engine configuration (SIDI), the Lexus RC with 1 (SIDI & PFI). Across 52 recorded Cadillac CT5 configurations and 50 for the Lexus RC, 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 Cadillac CT5 is offered with All-Wheel Drive, Rear-Wheel Drive, the Lexus RC 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 Midsize Cars and Subcompact 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 Cadillac CT5 emits 333 g/mile of CO2 versus 345 g/mile for the Lexus RC. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.

CT5 vs RC: common questions

Which is better on gas, the Cadillac CT5 or the Lexus RC?

The Cadillac CT5 is the more efficient of the two: it reaches 27 mpg combined versus 26 mpg for the Lexus RC, a 1 mpg advantage and costs about $100 less per year to fuel.

Which costs less to run per year?

By EPA estimates at 15,000 miles a year, the Cadillac CT5 runs about $2,800 a year in fuel at its most efficient configuration, versus about $2,900 for the Lexus RC — a difference of roughly $100 per year.

What engines do the CT5 and RC offer?

Cadillac CT5: SIDI. Lexus RC: SIDI & PFI.

Are they in the same vehicle class?

The EPA classifies the Cadillac CT5 as Midsize Cars and the Lexus RC as Subcompact Cars, so they aren't a like-for-like match on size.

More CT5 comparisons

More RC comparisons

Comparison id: cadillac-ct5-vs-lexus-rc