Cadillac CT4 vs Lexus IS

The Cadillac CT4 is the more efficient of the two: it reaches 27 mpg combined versus 26 mpg for the Lexus IS, a 1 mpg advantage and costs about $100 less per year to fuel.

Across 5 measured categories, the Cadillac CT4 leads in 5. Figures are EPA test data, not manufacturer claims.

2020–2026

Cadillac CT4

Compact Cars · 52 configurations

27mpg combined (best)
All Cadillac CT4 specs

2015–2026

Lexus IS

Compact Cars · 52 configurations

26mpg combined (best)
All Lexus IS specs

Head-to-head specifications

MetricCadillac CT4Lexus IS
Best combined MPG27 mpg26 mpg
Best city MPG23 mpg22 mpg
Best highway MPG34 mpg32 mpg
Lowest annual fuel costEPA estimate at 15,000 miles per year$2,800$2,900
Lowest CO2 output327 g/mi345 g/mi
Engines offeredSIDISIDI & PFI, SIDI
TransmissionsAutomatic (S8), Manual 6-spd, Automatic (S10)Automatic (S6), Automatic (S8)
DrivetrainsAll-Wheel Drive, Rear-Wheel DriveAll-Wheel Drive, Rear-Wheel Drive
Fuel typesPremiumPremium
EPA classCompact CarsCompact Cars
Years covered2020–20262015–2026
Configurations on record5252

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

CT4 vs IS: common questions

Which is better on gas, the Cadillac CT4 or the Lexus IS?

The Cadillac CT4 is the more efficient of the two: it reaches 27 mpg combined versus 26 mpg for the Lexus IS, 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 CT4 runs about $2,800 a year in fuel at its most efficient configuration, versus about $2,900 for the Lexus IS — a difference of roughly $100 per year.

What engines do the CT4 and IS offer?

Cadillac CT4: SIDI. Lexus IS: SIDI & PFI, SIDI.

Are they in the same vehicle class?

Yes — the EPA classifies both the Cadillac CT4 and the Lexus IS as Compact Cars, so they compete directly.

More CT4 comparisons

Comparison id: cadillac-ct4-vs-lexus-is