DecodedCarsAudi S4 vs Lexus IS
2025 Audi S4 vs 2025 Lexus IS — two compact cars compared on efficiency, size, safety and reliability.
The short version
The Lexus IS is more fuel-efficient: 25 vs 24 MPG combined in its best version.
That works out to about $100 a year less in fuel for the Lexus IS (EPA estimate, 15,000 miles).
The Audi S4 is the bigger car, about 2 inches longer.
Across all model years since 2005, the Audi S4 has had fewer recall campaigns (13 vs 15).
The two cars
The 2025 Audi S4 is a compact car offered with a 3.0L 6-cyl turbo engine and all-wheel drive. It measures about 188 inches long and 73 inches wide on a 111-inch wheelbase, with a curb weight of roughly 3,854 lb.
The 2025 Lexus IS is a compact car offered with 3 engines (2.0L 4-cyl turbo, 3.5L 6-cyl and 5.0L 8-cyl) and rear-wheel drive and all-wheel drive. It measures about 185 inches long and 72 inches wide on a 110-inch wheelbase, with a curb weight of roughly 3,715 lb (300 4dr Sedan RWD).
Buying used? The 2024 S4 and the 2024 IS have the fewest problems in our data; avoid the 2021 S4 and the 2015 IS.
Basics
Efficiency
Performance & space
Safety & reliability
Interest
Green = clearly better. Prices are not included. How we calculate this →
Pros & cons of each
2025 Audi S4
- No recalls so far
- Below-average fuel economyBest version gets 24 MPG combined, 16% below the 2025 compact car average of 28.6 MPG.
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
2025 Lexus IS
- AWD / 4WD available
- Lots of standard safety tech5 of 5 key driver aids standard on the versions we checked.
- No recalls so far
- Below-average fuel economyBest version gets 25 MPG combined, 13% below the 2025 compact car average of 28.6 MPG.
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
- Modest powerUp to 311 hp, versus about 396 hp for similar 2025 models.
Full 2025 Audi S4 specs →Full 2025 Lexus IS specs →Compare fuel costs for your driving →Compare size & garage fit →